JP2013038561A - Transmitter control device - Google Patents

Abstract

Provided is a transmission device control device that controls terminal power in consideration of antenna output characteristics, thereby reducing frequency-dependent characteristics of radiated power of radio waves output from an antenna and improving reception accuracy.
A transmission apparatus control device 1 according to the present invention includes an amplifier 2 that amplifies a data signal, an antenna 3 that receives an output signal of the amplifier 2 and outputs a transmission signal, and power (hereinafter referred to as power) of the output signal from the amplifier 2. , “Terminal power”) according to a predetermined condition based on the output characteristics of the antenna 3, and a control unit 4 that controls the power of a transmission signal output from the antenna 3 (hereinafter, “radiation”). The value of “power”) includes a correction value that falls within a certain range in a predetermined frequency band.
[Selection] Figure 1

Description

  The present invention relates to a transmission device control device that is used in a transmission device that outputs radio waves through an antenna, and that enables radiation output of a predetermined level or more over a wide band, corresponding to the radiation characteristics of the antenna provided in the transmission device.

  A transmitting device that outputs radio waves and transmits data is used in various applications and scenes. In particular, with the widespread use of mobile terminals such as mobile phones and smartphones, various transmission devices, reception devices, and transmission / reception devices that transmit and receive radio waves are used. For example, FM transmitters used in automobiles, wireless LAN devices, wireless hard disk drives, personal computer peripherals using radio waves, etc. communicate data using at least one of radio wave transmission and reception.

  A transmission apparatus using such a radio wave transmits a radio wave multiplied by a carrier wave through an antenna. At this time, the transmission apparatus includes a modulation unit that performs necessary modulation on the data signal, a multiplication unit that generates a radio wave by multiplying the modulated data signal by a carrier having a frequency determined by the standard, and a high-frequency amplifier that raises the radio wave to a predetermined level. (Hereinafter referred to as “RF amplifier”). In addition, an adjustment unit that adjusts the power of the radio wave output from the RF amplifier may be further provided.

  FIG. 12 is a block diagram of a part of a transmission apparatus in the prior art. The transmission device 800 includes other elements related to generation and processing of data signals, but is omitted in FIG. 12 for convenience of explanation. Transmitting apparatus 800 is amplified by modulation / demodulation unit 801 that modulates a data signal and multiplies a carrier wave, adjustment unit 802 that adjusts the output of RF amplifier 803, RF amplifier 803 that amplifies radio wave power to a predetermined level, and RF amplifier 803. An antenna 804 for outputting radio waves. The transmitting device 800 transmits radio waves to the receiving device through the antenna 804.

  Here, the output of the RF amplifier 803 is measured at the position A. The power of the output signal output at this position A is defined as “terminal power”. On the other hand, radio waves output from the RF amplifier 803 to the outside through the antenna 804 are measured at the position B. The power of the transmission signal output at this position B is defined as “radiant power”. The adjustment unit 802 and the RF amplifier 803 adjust the power of the transmission signal that is finally output from the antenna 804. However, the antennas used for the transmission apparatus including the antenna 804 have not only directivity characteristics but also output characteristics. This output characteristic varies the output power of the transmission signal, which is a radio wave, depending on the frequency band.

  FIG. 13 is an explanatory diagram showing the output characteristics of the antenna. Curve C in FIG. 13 shows the output characteristics of the antenna. This antenna may be the antenna 804 in FIG. 12 or a general antenna used in a transmission apparatus. As is apparent from the curve C, the output characteristics of the antenna have a peak output level in a certain frequency band, and the output level tends to decrease outside this frequency band.

  On the other hand, FIG. 14 is an explanatory diagram showing terminal power at position A, which is the output of the RF amplifier 803. The RF amplifier 803 adjusts the terminal power so as to be substantially flat over the entire frequency band required for transmission / reception (the entire frequency band is often divided into channels). As is apparent from FIG. 14, the terminal power is adjusted to be substantially flat from channel 1 to channel 7 having different frequency bands. Since the receiving device uses any one of the channels 1 to 7 as necessary in the received radio wave, the transmitting device has a predetermined terminal power in any of the channels 1 to 7 as shown in FIG. The adjustment part 802 adjusts output power so that it may become.

  However, although the terminal power is more than a certain value over the entire frequency band used for communication as shown in FIG. 14 (that is, over channel 1 to channel 7), the final output from the transmission device 800 is output. The radio wave varies depending on the antenna output characteristics shown in FIG. That is, the radiant power (the output power of the radio wave at position B in FIG. 12) depends on the antenna output characteristics.

  FIG. 15 is an explanatory diagram showing the radiated power that fluctuates depending on the antenna output characteristics in the prior art. Since the output from the RF amplifier 803 is output through the antenna 804, the transmission signal at the position B is a radio wave multiplied by the antenna output characteristic. For this reason, the channels 3 and 4 at the peak position of the antenna output characteristics show high radiated power, but the channels 1 and 7 at both ends show low radiated power. For example, when the threshold value of the radiant power that can be received without any problem (because the receiving device receives a radio wave based on this radiated power) is the broken line in FIG. 15, the receiving device is channel 3, channel 4, channel 5 can be received, but it is difficult to receive the radio waves of channel 2 and channel 6, and it is almost impossible to receive the transmission signals of channel 1 and channel 7.

  Thus, in the prior art, the terminal power at the RF amplifier of the transmission device is multiplied by the output characteristics of the antenna, so that the radiant power of the transmission signal actually output from the antenna 804 becomes the frequency band (channel ) Caused a problem that it was difficult to receive. In order to solve such problems, several technical proposals have been made (for example, see Patent Document 1 and Patent Document 2).

JP 2009-205237 A JP 2010-154421 A

  Patent Document 1 discloses a power amplifying unit that amplifies and outputs to an external antenna, a stabilized power source that supplies power to the power amplifying unit, and a module that transmits a pulse signal that indicates the amplification time of the power amplifying unit using a transmission instruction signal DC variable voltage source having a control circuit, a module control circuit, a power amplifying unit and a transmission / reception module housing a stabilized power source, and a control terminal for varying the output voltage to the stabilized power source via the power supply line and supplying the power And a control device that simultaneously sends a transmission instruction signal to the control terminal of the DC variable voltage source and the module control circuit, and the DC variable voltage source discloses an antenna device that boosts the DC output voltage during the transmission period of the transmission instruction signal. To do.

  That is, Patent Document 1 proposes a technique for preventing a variation in voltage supplied by a power source by preventing a decrease in power source voltage when a large pulse current is consumed by a transmission pulse.

  However, the technique disclosed in Patent Document 1 only considers the response to the power of the signal reaching the external antenna. That is, although consideration is given to the power supply voltage, etc., it does not consider improvement to the frequency band dependence of the radiated power caused by the antenna output characteristics. For this reason, the problem of the radiation power caused by the antenna output characteristics generated in the prior art as shown in FIG. 15 cannot be solved.

  Patent Document 2 describes a case where a signal output from a transmission circuit unit (corresponding to a signal having terminal power in FIG. 12) is output from an antenna terminal in a transmission device including both an antenna terminal and a transformer terminal. Disclosed is a technique for controlling the adjustment of the amplifier with the correction values of the antenna terminal and the transparter terminal when output from the transpartor terminal.

  However, even if the amplifier is adjusted by a correction value based on the antenna terminal, Patent Document 2 takes into account variations in parts, differences from characteristics of the transparter, and the like, and a frequency-dependent antenna. It does not consider correcting the output characteristics. For this reason, the technique of Patent Document 2 also has a problem that the frequency dependence of the radiated power generated by the antenna output characteristics cannot be reduced, as in the technique of Patent Document 1.

  As described above, the proposed technique does not consider the output characteristics of the antenna when adjusting or controlling the power of the radio wave reaching the antenna (terminal power at the position A shown in FIG. 12). Or whether to increase the peak output or total output, or to improve the receiving accuracy by devising the receiving apparatus.

  That is, it is required to reduce the frequency dependence of the radiation power of the radio wave actually output from the antenna by controlling the terminal power reaching the antenna in advance based on the antenna output characteristics.

  In view of the above-described problems, the present invention reduces the frequency-dependent characteristics of the radiated power of radio waves output from an antenna and improves the reception accuracy by controlling the terminal power in consideration of the antenna output characteristics. The purpose is to provide.

  In view of the above problems, a transmission device control device of the present invention includes an amplifier that amplifies a data signal, an antenna that receives the output signal of the amplifier and outputs a transmission signal, and power of the output signal from the amplifier (hereinafter referred to as “terminal power”). And a control unit that controls the power of a transmission signal output from the antenna (hereinafter referred to as “radiant power”). And a correction value that falls within a certain range in a predetermined frequency band.

  The transmitter control device of the present invention can determine the terminal power corresponding to the antenna output characteristic based on the frequency dependence. As a result, it is possible to reduce the frequency dependence of the radiated power of the radio wave output under the influence of the antenna output characteristics. In other words, the radio wave output from the antenna shows power that falls within a certain range with little dependence on the frequency.

  In addition, since the radio wave output from the transmission device by the transmission device control device has a constant power regardless of the frequency, the reception accuracy in the reception device is improved. In particular, a receiving device that receives signals while switching the frequency band has more options for the receiving band, which increases convenience for the user of the receiving device.

  As a result, the usability of various applications including a transmission / reception device by wireless communication is increased, and the spread of these is further promoted.

It is a block diagram of the transmission apparatus control device in Embodiment 1 of this invention. It is a graph which shows the radiant power of the transmission signal from the transmission apparatus control device in Embodiment 1 of this invention. It is a graph which shows control of the terminal electric power by the control part in Embodiment 1 of this invention. It is a schematic diagram of the output characteristic of the antenna in Embodiment 1 of this invention. It is a graph which shows the radiant power of the transmission signal in Embodiment 1 of this invention. It is a graph which shows the radiant power of the transmission signal in Embodiment 1 of invention. It is a block diagram of the transmission apparatus control device in Embodiment 2 of this invention. It is a schematic diagram which shows the communication state of the communication apparatus in Embodiment 2 of this invention. It is a graph which shows the radiant power of the transmission signal received with the receiver in Embodiment 2 of this invention. It is a graph of the terminal electric power after control in Embodiment 2 of the present invention. It is a block diagram of the radio | wireless apparatus in Embodiment 2 of this invention. It is a one part block diagram of the transmitter in a prior art. It is explanatory drawing which shows the output characteristic of an antenna. 7 is an explanatory diagram showing terminal power at position A, which is an output of an RF amplifier 803. FIG. It is explanatory drawing which shows the radiant power changed with the antenna output characteristics in a prior art.

  A transmitter control device according to a first aspect of the present invention includes an amplifier that amplifies a data signal, an antenna that receives an output signal of the amplifier and outputs a transmission signal, and power (hereinafter referred to as “terminal”) of the output signal from the amplifier. A control unit that controls the power according to a predetermined condition based on the output characteristics of the antenna, and the predetermined condition is a value of power of a transmission signal output from the antenna (hereinafter referred to as “radiant power”). Is included in a predetermined range in a predetermined frequency band.

  With this configuration, the transmission device control device can reduce the frequency dependency of the radiated power in a predetermined frequency band even when the output characteristic of the antenna is changed.

  In the transmission device control device according to the second aspect of the present invention, in addition to the first aspect, the control unit keeps the value of the radiant power in the predetermined frequency band substantially the same based on the predetermined condition.

  With this configuration, the transmission device control device can keep the radiation power of the output transmission signal constant regardless of the output characteristics of the antenna. As a result, in reception, it becomes difficult to generate a band that makes reception difficult.

  In the transmitter control device according to the third aspect of the present invention, in addition to the first or second aspect, the control unit multiplies the output signal of the amplifier by the correction value.

  With this configuration, the control unit can easily control the terminal power of the output signal of the amplifier.

  In the transmission device control device according to the fourth aspect of the present invention, in addition to any one of the first to third aspects, the correction value corresponds to a curve that is symmetrical with the output characteristic of the antenna.

  With this configuration, the transmission device control device can keep the radiation power of the transmission signal output from the antenna at a certain level.

  In the transmission device control device according to the fifth aspect of the present invention, in addition to the fourth aspect, the correction value has a characteristic opposite to the output characteristic of the antenna.

  With this configuration, the transmission device control device can keep the radiant power of the transmission signal output from the antenna at a substantially constant level.

  In the transmission device control device according to the sixth aspect of the present invention, in addition to any one of the first to fifth aspects, the control unit includes at least one of an input signal input to the amplifier and an output signal output from the amplifier. Control power.

  With this configuration, the control unit can control the terminal power in accordance with the configuration of the transmission device.

  In the transmission device control device according to the seventh aspect of the present invention, in addition to any one of the first to sixth aspects, the correction value is determined based on output characteristics obtained for each antenna connected to the amplifier. It is done.

  With this configuration, the control unit can use a correction value suitable for the type and configuration of the antenna. As a result, radiation power that does not depend on the output characteristics of the antenna can be realized.

  In the transmission device control device according to the eighth aspect of the present invention, in addition to any one of the first to seventh aspects, the correction value may be subjected to adjustment corresponding to component variations of the antenna connected to the amplifier. Is possible.

  With this configuration, the control unit can use a more accurate correction value.

  In the transmission device control device according to the ninth aspect of the present invention, in addition to any of the first to eighth aspects, the correction value is adjusted based on the reception state at the reception device that receives the transmission signal from the antenna. It is possible to receive.

  With this configuration, the control unit can control terminal power that dynamically corresponds to the reception state.

  The transmitting apparatus control device according to the tenth aspect of the present invention further includes a storage unit for storing correction values in addition to any of the first to tenth aspects.

  With this configuration, the correction value becomes programmable.

  In the transmission device control device according to the eleventh aspect of the present invention, in addition to any one of the first to tenth aspects, the control unit is realized by at least a part of functions of the microprocessor.

  With this configuration, the transmission device control device can effectively utilize the elements included in the transmission device.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  (Embodiment 1)

(Overview)
First, an overall outline of the transmission apparatus control device according to Embodiment 1 will be described with reference to FIG. FIG. 1 is a block diagram of a transmission device control device according to Embodiment 1 of the present invention. The transmission apparatus control device 1 includes an amplifier 2, an antenna 3, and a control unit 4.

  The amplifier 2 amplifies the data signal. For example, an RF amplifier or a low noise amplifier is used as the amplifier 2. The antenna 3 receives the output signal of the amplifier 2 and outputs a transmission signal. In other words, an output signal that is the signal itself amplified by the amplifier 2 is present before the antenna 3, and a transmission signal that is a radio wave transmitted by the antenna 3 is present after the antenna 3.

  The control unit 4 controls the power of the output signal from the amplifier 2 (hereinafter referred to as “terminal power”, which indicates the power at the position E in FIG. 1) according to a predetermined condition based on the output characteristics of the antenna 3. At this time, the predetermined condition is a correction value that keeps the value of the power of the transmission signal output from the antenna 3 (hereinafter referred to as “radiation power”, which indicates the position F in FIG. 1) within a certain range in the predetermined frequency band. Is included.

  The transmission apparatus control device 1 according to the first embodiment has such a configuration, and thus can prevent variations in radiant power depending on the frequency of the transmission signal that may occur due to the output characteristics of the antenna 3.

  Here, it is a state as shown in FIG. 2 that the radiated power falls within a certain range in a predetermined frequency band. FIG. 2 is a graph showing the radiant power of the transmission signal from the transmission apparatus control device according to Embodiment 1 of the present invention. In the graph of FIG. 2, the band from channel 1 to channel 7 is a predetermined frequency band. This predetermined frequency band indicates, for example, a band permitted in an application that performs certain wireless communication. For example, the frequency band allowed for FM radio and the frequency band allowed for wireless LAN. The application using this predetermined frequency band selects which channel from channel 1 to channel 7 is used according to the transmission / reception status and transmission / reception specifications of the transmission device and the reception device.

  For example, when the application is an in-vehicle FM transmitter, the FM transmitter searches for a channel not used by the FM radio in a place where the mounted vehicle is located. For example, when channels 1, 2, 4 to 6 are used for FM radio, the FM transmitter needs to use channels 3 and 7, which are free bands. Alternatively, applications such as mobile phones, cordless phones, wireless LANs, and RF-ID devices are also available in channels included in a predetermined frequency band defined by the standard (channels that are not used or channels that can be used preferentially, etc.) ).

  Here, in the conventional transmission apparatus, the amplifier outputs an output signal so that the terminal power at the output of the amplifier is constant regardless of the channel. This is the state described with reference to FIG. Here, the antenna has an output characteristic in which its gain changes depending on the frequency. Therefore, if the terminal power of the output signal output from the amplifier is constant, the transmission signal finally output from the antenna The intensity of the radiant power varies depending on the antenna output characteristics. In many cases, an antenna of a normal transmission apparatus is adjusted so that the gain peak is in the vicinity of the center frequency in the small and low frequency band. For this reason, the transmission signal output from the antenna of the transmission apparatus of the prior art may have a small radiant power in the channel near both ends of the predetermined frequency band, as shown in FIG. In some cases, a receiving device that receives a transmission signal from the transmitting device may not be able to receive (cannot receive or demodulate) a channel radio wave corresponding to the reduced radiation power.

  For example, as described above, when only channel 3 and channel 7 are available, even if channel 7 is selected, reception is not possible. In addition, although the radio waves of channel 3 can be received, applications such as FM transmitters and wireless LANs are naturally concentrated on the empty channel 3, and as a result, communication concentrates on channel 3, resulting in an application that cannot communicate. End up. That is, all of the channels 1 to 7 that are permitted as the predetermined frequency band are not utilized for communication.

  On the other hand, as shown in FIG. 2, when the radiant power of the transmission signal output from the antenna 3 falls within a certain range, the transmission signal actually communicated as a radio wave is channel 1 to channel. 7 has a receivable level. For this reason, for example, when channel 3 and channel 7 are vacant channels, the receiving apparatus can select both channel 3 and channel 7 and can receive and demodulate. As a result, an application that performs communication using a predetermined frequency band can effectively use all channels included in the predetermined frequency band. As a result, for example, it becomes easy to suppress the maximum output of the antenna 3 (in the conventional technology, in order to make the radiant power of all the channels exceed the threshold as much as possible, the antenna power is limited to the upper limit allowed by the standards and regulations. It was necessary to increase the maximum output), and the design flexibility of the transmitting device and the receiving device itself is increased.

  The control unit 4 controls the terminal power of the output signal of the amplifier 2 so that the radiant power of the transmission signal output from the antenna 3 falls within a certain width as shown in FIG. For this purpose, the control unit 4 controls the terminal power to have a characteristic that is symmetric to the output characteristic of the antenna 3 (curve G in FIG. 2). That is, it is preferable that the control unit 4 controls the output signal of the amplifier 2 as shown in FIG. FIG. 3 is a graph showing terminal power control by the control unit according to Embodiment 1 of the present invention.

  A curve G in FIG. 2 is an output characteristic of the antenna 3. For this reason, the control unit 4 controls the terminal power so that the terminal power corresponds to a curve symmetric with the curve G. More specifically, the control unit 4 controls the terminal power using a correction value corresponding to the curve H that is symmetric to the curve H as a predetermined condition. The curve H in FIG. 3 is a curve that is symmetrical with the curve G corresponding to the output characteristics of the antenna 3 as described above. The correction value used for control by the control unit 4 corresponds to this curve H. By controlling the terminal power of the output signal of the amplifier 2 as shown in FIG. 3 (that is, the terminal power of the channel 1 and the channel 7 at both ends of the predetermined frequency band is large, the channels 3 and 4 near the center are The terminal power is controlled to be small), and finally the radiation power of the transmission signal after being multiplied by the output characteristic of the antenna falls within a certain range as shown in FIG.

  By controlling the terminal power in advance by the control unit 4, the radiated power of the output transmission signal is within a certain range of power values. The transmission signal having the radiation power as shown in FIG. 2 is output from the transmission device, so that any one of the channels 1 to 7 does not have a very low radiation power. In this case, the receiving apparatus can select any one of the channels 1 to 7 included in the predetermined frequency band (if the channel is free). For this reason, the application using the transmission apparatus can improve the frequency usage efficiency, and can realize the reduction of the communication traffic and the improvement of the reception performance.

  Next, the detail of each part is demonstrated.

(Modulator / Demodulator)
The modem 5 generates a basic data signal output from the transmission device control device. For example, when the transmission apparatus transmits an image signal, the data obtained by converting the image data into digital data is encoded by receiving frequency modulation, phase modulation, amplitude modulation, or the like. A data signal is generated by multiplying the encoded signal by a necessary carrier wave. The modem 5 generates this data signal.

  Further, the modem 5 generates a data signal by modulating data when the transmission device outputs a transmission signal. However, when the reception device is used for the reception device and receives the reception signal, the modulation / demodulation unit 5 Demodulate to get the original data. The transmission apparatus control device 1 may be used for a transmission apparatus that performs only transmission, or may be used for a transmission / reception apparatus that performs both transmission and reception. The same algorithm or standard is used for demodulation corresponding to modulation. For example, when the modulation uses PSK modulation or QPSK modulation, PSK demodulation corresponding to this PSK modulation and QPSK demodulation corresponding to QPSK modulation are also used for demodulation. Therefore, the modem unit 5 performs at least one of modulation and demodulation according to the necessity of the device to be used.

  Note that the transmission device control device 1 does not necessarily include the modem unit 5 as an essential element. The modulation / demodulation unit 5 may be provided separately from the transmission device control device 1 as long as the transmission device control device 1 can receive a data signal from the modulation / demodulation unit 5 included in the transmission device or the transmission / reception device.

(amplifier)
The amplifier 2 amplifies the data signal from the modem unit 5. Since the data signal is generated by a semiconductor integrated circuit such as a baseband IC, it has power and voltage according to the power and voltage used in the semiconductor integrated circuit. With this power and voltage, even if it is a radio wave multiplied by a carrier wave, it becomes a very weak radio wave when it is output from the antenna 3. For this reason, the amplifier 2 amplifies the power and voltage of the data signal so that the radio wave from the antenna 3 becomes sufficient power.

  The amplifier 2 may amplify the data signal using an amplifier such as an RF amplifier or an operational amplifier. As the RF amplifier and the operational amplifier used here, elements known in the art may be used. In addition, an amplification element having specifications required to be used in the standard of the transmission device may be used.

  The amplifier 2 amplifies the data signal based on the control from the control unit 4. When the data signal is amplified based on the control from the control unit 4, for example, the terminal power for each channel as shown in FIG. 3 is obtained. That is, the amplifier 2 performs the data signal amplification process not only according to the specifications determined by the amplifier 2 but also according to the specifications determined by the control unit 4.

  Since the amplifier 2 is controlled by the control unit 4, the general amplifier 2 and the control unit 4 may be provided separately. Alternatively, the amplifier 2 and the control unit 4 may be designed and manufactured as one element and incorporated in the transmission device control device 1. The amplifier 2 itself may be provided with an adjusting device for adjusting the amplification level. In this case, the control unit 4 may have a function of outputting a control signal for controlling the adjusting device. Alternatively, the control unit 4 may be included in an adjustment device included in the amplifier 2. For example, if the adjustment device is programmable, the amplifier 2 can amplify the data signal so as to correspond to the terminal power as shown in FIG. 3 by setting this program.

  As will be described later, the amplifier 2 can control the output of the amplifier 2 or control the signal input to the amplifier 2. For this reason, the amplifier 2 not only receives the control of the control unit 4, but also only amplifies the data signal after being controlled. For this reason, when the control unit 4 controls the amplifier 2, the amplifier 2 amplifies the data signal while being controlled by the control unit 4. When the control unit 4 controls a signal input to the amplifier 2, the amplifier 2 amplifies the data signal.

  As described above, the amplifier 2 amplifies and outputs the data signal while being related to the control of the control unit 4.

(antenna)
The antenna 3 uses the output signal of the amplifier 2 as a transmission signal and outputs it as a radio wave. The amplifier 2 amplifies the data signal and outputs an output signal to the antenna 3. The antenna 3 outputs this output signal as a radio wave based on the material and structure of the antenna 3. The antenna 3 has a length and shape determined based on the wavelength of the transmission signal. For example, it is preferable to have a length such as a half wavelength that is a half of the wavelength or a quarter wavelength that is a quarter of the wavelength.

  The antenna 3 may include an antenna member formed of a so-called metal rod-shaped member, or may include a chip antenna or a coil antenna that is an electronic component, or by a pattern printed on an electronic substrate. A pattern antenna may be provided. An antenna member used in a general transmission device or wireless device may be used as the antenna 3.

  The antenna 3 has output characteristics depending on its impedance and frequency. This output characteristic has a change in peak radiation power and radiation power depending on the frequency band. Based on the impedance characteristics of the antenna 3 itself, the potential relationship between the antenna 3 and the ground plane, the impedance characteristics of electronic components connected to the antenna 3, the antenna 3 has such frequency-dependent output characteristics. .

  FIG. 4 is a schematic diagram of the output characteristics of the antenna according to the first embodiment of the present invention. The output characteristics of the antenna 3 shown in FIG. A curve G shows the output characteristics of the antenna 3. The peak frequency indicating the peak value of the antenna 3 is determined by the impedance characteristics. In FIG. 4, position I is the peak frequency. According to this peak frequency, as shown by a curve G, the radiation power has output characteristics that gradually change in the frequency band. In other words, the antenna 3 cannot have output characteristics that provide flat radiation power that does not depend on the frequency, regardless of which antenna is used.

  Since it has output characteristics like the curve G, the radiation power of the transmission signal output by the antenna 3 must be in a state in which the curve G is multiplied. In the transmission apparatus control device 1 according to the first embodiment, the output signal input to the antenna 3 is controlled in advance by the control unit 4 in a state in which this curve G is taken into consideration. 2 is controlled. However, the antenna 3 must have output characteristics like the curve G. The control unit 4 uses the output characteristic represented by the curve G in reverse to reduce the frequency dependence of the radiant power of the transmission signal.

  The antenna 3 may be provided integrally with the transmission device or may be provided separately. The antenna 3 is shown as a separate body from the amplifier 2 and the like in FIG. Since the antenna 3 is an independent member, it is often a separate member. However, the antenna 3 and the amplifier 2 may be integrated, for example, like the antenna 3 including the amplifier 2. Alternatively, the element that controls the antenna 3 may have at least a part of the functions of the amplifier 2 and the control unit 4. In this case, the antenna 3 and a part (or all) of the other elements are integrated. It can also be grasped as an element that became. The transmission apparatus control device 1 according to the first embodiment shown in FIG. 1 does not have to be grasped separately as the elements shown in FIG. This is the same in all of the amplifier 2, the control unit 4, and the modem unit 5.

(Control part)
The control unit 4 controls terminal power that is the power of the output signal of the amplifier 2. At this time, as shown in FIG. 2, the terminal power is controlled according to a predetermined condition having a correction value in which the radiant power of the transmission signal output from the antenna 3 falls within a certain range. That is, the control unit 4 controls the terminal power so that the value of the radiant power of the transmission signal that is finally output from the antenna 3 falls within a certain range in the predetermined frequency band. That is, the control unit 4 has a correction value corresponding to the output characteristics of the antenna 3 in advance, and uses this correction value to control the terminal power.

  The control unit 4 controls the output signal of the amplifier 2 input to the antenna 3 according to the output characteristics of the antenna 3. This is as shown in FIG. That is, the control unit 4 controls the terminal power of the output signal of the amplifier 2 as shown in FIG. 3 in a predetermined frequency band. The output characteristic of the antenna 3 has a curve as shown by the curve G. The control unit 4 controls the terminal power of the output signal using a correction value such as a curve H that is symmetric to the curve G. That is, by multiplying the output signal by the correction value according to the curve H, the terminal power as shown in the channels 1 to 7 in FIG. 3 is controlled. After reaching the terminal power state as shown in FIG. 3, the output signal is multiplied by a curve G (FIG. 4) that is an output characteristic of the antenna 3. As a result, the antenna 3 comes to output a transmission signal having radiation power as shown in FIG. FIG. 5 is a graph showing the radiant power of the transmission signal in Embodiment 1 of the present invention.

  As shown in FIG. 5, the radiant power of the transmission signal falls within a certain width in channel 1 to channel 7. Since all of channel 1 to channel 7 fall within a certain width, a receiving device that receives this radio wave can receive any of channel 1 to channel 7 and can effectively use a predetermined frequency band. .

  Here, the control unit 4 controls the power of at least one of the input signal input to the amplifier 2 and the output signal output from the amplifier 2. The control unit 4 performs control so that the output signal output from the amplifier 2 has terminal power as shown in FIG. That is, it is only necessary that the output signal finally input to the antenna 3 has the terminal power shown in FIG. For this reason, the control unit 4 applies the signal input to the amplifier 2 to the terminal power as shown in FIG. 3 (not the absolute value but the difference in the terminal power of each of the channels 1 to 7 shows the tendency as shown in FIG. May be controlled). If the signal input to the amplifier 2 has a tendency as shown in FIG. 3 in the channels 1 to 7, the signals of the channels 1 to 7 amplified by the amplifier 2 maintain this tendency. It is amplified as it is. As a result, the amplifier 2 can output an output signal having terminal power corresponding to the output characteristics of the antenna 3 to the antenna 3.

  On the other hand, the control unit 4 may control the amplifier 2 so that the output signal output from the amplifier 2 has terminal power as shown in FIG. Also in this case, the amplifier 2 can output an output signal having terminal power corresponding to the output characteristics of the antenna 3.

  The control unit 4 controls the terminal power of the output signal of the amplifier 2 using a correction value based on the output characteristics of the antenna 3. At this time, it is also preferable to control so that the value of the radiant power of the transmission signal output from the antenna 3 is substantially the same as shown in FIG. FIG. 6 is a graph showing the radiant power of the transmission signal in Embodiment 1 of the present invention. Even if they are substantially the same, they do not require perfect identity, but indicate the extent to which they are generally within the same value. In order for the radiated power to be substantially the same, the control unit 4 may multiply the output signal of the amplifier 2 by a correction value having substantially perfect symmetry with the output characteristics of the antenna 3. At this time, since the output characteristics of the antenna 3 are obtained by measurement of the antenna 3, the control unit 4 may have a correction value calculated from the obtained output characteristics of the antenna 3.

  Further, substantially perfect symmetry may be grasped by the inverse characteristic of the output characteristic of the antenna 3. The control unit 4 has a correction value obtained from the inverse characteristic of the output characteristic of the antenna 3, and the control unit 4 multiplies the output signal of the amplifier 2 by the correction value corresponding to this inverse characteristic. A transmission signal is obtained in which the radiant power from channel 1 to channel 7 as shown in FIG.

  Or the control part 4 may control the output signal of the amplifier 2 so that the radiation power of a certain channel may become larger than the radiation power of another channel. For example, when a predetermined frequency band includes channels 1 to 7, only a certain channel may be frequently used. For example, when the transmitter control device 1 is used for an FM transmitter, the FM transmitter uses a channel that is not used by the FM radio. FM radio tends to be biased to a specific channel in order to improve transmission / reception accuracy, and a specific channel may become an empty channel when an FM transmitter is used. For example, in many cases, a channel at an end of a predetermined frequency band such as channel 1 and channel 7 shown in FIG.

  In such a case, the control unit 4 determines that the radiant power of the transmission signal from the antenna 3 is larger than the radiant powers of the other channels. It is also suitable to control. That is, the control unit 4 controls the terminal power of the channel 1 and the channel 7 so as to be very large. As a result, the transmission apparatus using the transmission apparatus control device 1 can easily perform transmission / reception on a channel that is easily available. Of course, the control of channel 1 and channel 7 is an example.

(Correction value)
The correction value is obtained from the output characteristics of the antenna 3. A correction value is obtained by measuring in advance the output characteristics of the antenna 3 used in the transmitter control device 1. At this time, the output characteristics of the antenna 3 may be measured for each type (type by structure, function, etc., type by product number, etc.). In this case, the correction value depends on the type of the antenna 3. That is, the correction value is the same for the same type of antenna 3.

  Alternatively, the output characteristics may be measured for each antenna 3 used in the transmission device control device 1. In this case, the correction value is stored in the control unit 4 according to each of the antennas 3. In the latter case, there is a merit that it is possible to cope with the characteristics and manufacturing variations of the transmission device, but the development cost increases. In this case, a correction value may be determined for each type of antenna 3 as in the former case.

  Further, as in the latter case, even if the correction value is not calculated after the output characteristics are measured for each antenna 3 to be used, the correction value may be subjected to adjustment corresponding to the component variation of the antenna 3. For example, the control unit 4 has a correction value corresponding to the type of the antenna 3. Although the correction value has a correction value corresponding to the type of the antenna 3, the correction value may be adjusted by receiving an adjustment in consideration of component variations of the antenna 3. For example, the control unit 4 may perform operations such as taking into account empirical component variations of the antenna 3 and adjusting based on transmission / reception accuracy in transmission / reception.

  The transmission apparatus and the reception apparatus in which the transmission apparatus control device 1 is used can detect the accuracy in transmission / reception. The control unit 4 can receive the transmission / reception accuracy and determine an adjustment level based on the transmission / reception accuracy. The control unit 4 controls the correction value according to the determined adjustment level.

  The control unit 4 may be realized by at least a part of the functions of the microprocessor included in the transmission device control device 1 or the transmission device. In general, the transmission device and the transmission / reception device include a microprocessor. The microprocessor can execute various functions by reading a program stored in the memory. At this time, if the function of the control unit 4 is stored in the memory as a program, the microprocessor can realize the function of the control unit 4. That is, the function of the control unit 4 is realized by a microprocessor and a program executed by the microprocessor.

  This microprocessor may realize the functions of elements other than the control unit 4 (for example, the function of the modulation / demodulation unit 5), and a general-purpose microprocessor required in a transmission device or the like realizes the function of the control unit 4. do it.

  As described above, the control unit 4 controls the output signal using the correction value. By this control, it is possible to prevent the occurrence of a channel in which the radiation power is reduced below the threshold value due to the output characteristics of the antenna 3.

  The transmission device control device 1 according to the first embodiment does not cause a channel in which the radiated power becomes weak regardless of the output characteristics of the antenna. As a result, it is possible to realize communication that effectively uses the assigned frequency band.

  (Embodiment 2)

  Next, a second embodiment will be described. In the second embodiment, other devices in the transmission device control device 1 will be described.

(Memory part)
The transmission device control device 1 may further include a storage unit that stores the correction value. FIG. 7 is a block diagram of a transmission apparatus control device according to Embodiment 2 of the present invention. The transmission device control device 1 includes a storage unit 8. The storage unit 8 stores correction values used by the control unit 4. The correction value is a discrete value or represented by a mathematical expression, but the storage unit 8 stores the discrete value or mathematical expression as a correction value.

  The storage unit 8 can output the stored correction value to the control unit 4. Alternatively, the control unit 4 can read the correction value stored in the storage unit 8. The storage unit 8 is provided separately from the control unit 4 and stores the correction value, whereby the correction value becomes programmable. The contents of the storage unit 8 can be rewritten from the outside. For example, rewriting can be performed from other elements of the transmission device, and rewriting can be performed from outside the transmission device.

  Since the storage unit 8 can rewrite the stored value, there is an advantage that the optimum correction value for the transmission device control device 1 can be updated at any time. For example, a certain correction value is used for a certain transmission apparatus control device 1. This is a correction value determined to be optimal when the transmitter control device 1 is designed. However, a channel that is frequently used among the channels included in the predetermined frequency band may fluctuate due to a change in the standard of the transmission device that uses the transmission device control device 1 or a change in the use region. In this case, it is preferable that the correction value is rewritten so that the radiant power of the frequently used channel is controlled to be high.

  For example, the modem unit 5 detects the transmission accuracy and the reception accuracy, and detects which channel needs to increase the radiation power from the transmission accuracy and the reception accuracy. Depending on this detection, the correction value may need to be changed. The modem unit 5 instructs the storage unit 8 to change the correction value, and the correction value stored in the storage unit 8 is rewritten. The control unit 4 can control the terminal power of the output signal of the amplifier 2 using the rewritten correction value. As a result, the transmission apparatus control device 1 can output a transmission signal that matches the change in the transmission / reception state.

  When the storage unit 8 is rewritten from the outside, a user using the transmission device rewrites the correction value in the storage unit 8 through an operation of a switch or a program or a program.

  As described above, the storage unit 8 being provided and the correction value can be updated is also suitable for the transmission device control device 1 to be used in various situations.

(Dynamic control)
The control unit 4 is provided in the transmission device control device 1 used for the transmission device. The control unit 4 controls the terminal power of the output signal of the amplifier 2 based on a correction value obtained based on the output characteristics of the antenna 3 of the transmission device control device 1. That is, the static control is focused on only the transmission device.

  As described in the first embodiment, the transmission signal output from the antenna 3 under the control of the control unit 4 has a small difference in radiant power depending on the frequency. However, this control is performed based on the characteristics of the transmission device and the antenna 3. It does not take into account the temporal variation of the actual transmission / reception state.

  For example, depending on the state change of transmission / reception, fluctuations such as the reception state of a certain band having a predetermined frequency band becoming extremely bad or good may occur in time. Depending on the reception environment, the reception state of a certain channel may be extremely deteriorated. In this case, as shown in FIG. 2, even if a transmission signal having a radiant power that falls within a certain width is output, it is difficult for the reception device to receive a transmission signal of a channel that has deteriorated extremely.

  The transmission device and the reception device exchange information with each other through communication. FIG. 8 is a schematic diagram showing a communication state of the communication apparatus according to Embodiment 2 of the present invention. The transmission device 10 and the reception device 20 communicate using radio signals. Each of the transmission device 10 and the reception device 20 may have both transmission and reception functions.

  The transmission apparatus 10 includes the transmission apparatus control device 1 and controls the radiant power of the transmission signal output from the antenna 3 so as to be within a certain width in a predetermined frequency band. That is, when each of the plurality of channels included in the predetermined frequency band is output from the antenna 3, the difference from the radiant power of the other channels is not large, and all channels are considered if the reception environment is not considered. However, it has radiant power exceeding the threshold which can be received. The receiving device 20 receives a transmission signal transmitted from the transmitting device 10 through the antenna 23. The receiving unit 21 receives a signal received by the antenna 23. The demodulator 22 demodulates the received signal and extracts necessary data.

  At this time, the reception unit 21 and the demodulation unit 22 can determine the reception state. The reception state may fluctuate due to changes in the reception environment and other communication states, and the reception unit 21 and the demodulation unit 22 can detect this change in reception state. For example, when communication is performed using a certain channel, the reception state of this channel may be extremely deteriorated due to a change in the reception environment. In this case, it is preferable that the transmission device 10 and the reception device 20 switch communication to another channel. However, when other channels are not available, channel switching cannot be performed.

  FIG. 9 is a graph showing the radiant power of the transmission signal received by the receiving apparatus according to Embodiment 2 of the present invention. For example, the transmission device 10 and the reception device 20 communicate using the channel 3. At this time, the radiation power of the channel 3 may decrease due to a change in the reception environment. FIG. 9 shows a state where the radiant power of the channel 3 is lowered. The radiated power of channel 3 is below the receivable threshold.

  In this case, the receiving device 20 determines that the radiated power of the channel 3 is insufficient, and notifies the transmitting device 10 to that effect. The transmitter 10 increases the radiant power of the channel 3 based on the fact that the radiant power of the channel 3 being used is reduced (in the receiver 20). At this time, the transmitter control device 1 controls terminal power that is the power of the output signal of the amplifier 2. For example, as illustrated in FIG. 10, the transmission device control device 1 increases the value of the channel 3 in the terminal power. FIG. 10 is a graph of terminal power after control in the second embodiment of the present invention. Originally, it is appropriate to reduce the terminal power of channel 3 according to the output characteristics of antenna 3, but based on the fact that the radiated power of channel 3 is insufficient, the value is set when the terminal power is used. Enlarge. As a result, the radiant power of the channel 3 in the transmission signal output from the antenna 3 becomes a sufficient value, and the receiving device 20 can reliably receive the signal of the channel 3.

  At this time, the control unit 4 can control the terminal power as shown in FIG. 10 by adjusting the correction value for correcting the output of the amplifier 2 based on the reception state in the reception device 20.

  As described above, the transmission device control device 1 can dynamically control the terminal power with respect to the change in the reception state in the reception device 20.

(Application of transmitter control device)
The transmission device control device 1 described in the first and second embodiments is applied to various devices and apparatuses. FIG. 11 is a block diagram of a wireless device according to Embodiment 2 of the present invention.

  The wireless device 30 includes at least one of the transmission device control device 1 described in the first and second embodiments, the transmission circuit 31 that outputs a data signal to the transmission device control device 1, and the transmission device control device 1 and the transmission circuit 31. A control circuit 32 for controlling is provided. The transmission apparatus control device 1 outputs the data signal output from the transmission circuit 31 as a transmission signal from the antenna 3. At this time, the terminal power is controlled based on the output characteristics of the antenna 3 as described in the first and second embodiments. As a result, the wireless device 30 can reduce the frequency dependence of the radiated power of the transmission signal in the predetermined frequency band.

  As described above, the wireless device 30 including the transmission device control device 1 can reduce the difference in the radiant power of the transmission signal in the predetermined frequency band regardless of the output characteristics of the antenna 3. As a result, the wireless device 30 can perform communication by effectively utilizing a predetermined frequency band that is permitted to be used.

  Here, the wireless device 30 is also preferably at least one of a radio microphone, a transceiver, a cordless telephone, a computer peripheral device, a wireless speaker, a wireless microphone, a wireless medical device, an FM transmitter, an RF-ID device, and a wireless power feeding device. It is. These devices perform wireless communication using a predetermined frequency band. Also in this case, since these wireless devices 30 include the transmission device control device 1, a predetermined frequency band can be effectively used.

  As described above, the transmission device control device 1 can be applied to various wireless devices and communication devices, and the applied wireless device and communication device can effectively use a predetermined frequency band and execute optimal wireless communication. .

  The transmission device control device described in the first and second embodiments is an example for explaining the gist of the present invention, and includes modifications and modifications without departing from the gist of the present invention.

DESCRIPTION OF SYMBOLS 1 Transmitter control device 2 Amplifier 3 Antenna 4 Controller 5 Modulator / Demodulator 8 Storage unit 10 Transmitter 20 Receiver 21 Receiver 22 Demodulator 30 Radio equipment 31 Transmitter circuit 32 Control circuit

Claims (13)

An amplifier for amplifying the data signal;
An antenna that receives an output signal of the amplifier and outputs a transmission signal;
A controller that controls the power of the output signal from the amplifier (hereinafter referred to as “terminal power”) according to a predetermined condition based on the output characteristics of the antenna;
The transmission apparatus control device, wherein the predetermined condition includes a correction value that keeps a value of power (hereinafter referred to as “radiation power”) of a transmission signal output from the antenna within a predetermined range in a predetermined frequency band.   The transmission device control device according to claim 1, wherein the control unit stores the value of the radiated power in the predetermined frequency band substantially the same based on the predetermined condition.   The transmission device control device according to claim 1, wherein the control unit multiplies the output value of the amplifier by the correction value.   The transmission apparatus control device according to claim 1, wherein the correction value corresponds to a curve that is symmetric to the output characteristic of the antenna.   The transmission apparatus control device according to claim 4, wherein the correction value has a characteristic opposite to an output characteristic of the antenna.   The transmission apparatus control device according to claim 1, wherein the control unit controls power of at least one of an input signal input to the amplifier and an output signal output from the amplifier.   The transmission apparatus control device according to claim 1, wherein the correction value is determined based on an output characteristic obtained for each antenna connected to the amplifier.   The transmission apparatus control device according to claim 1, wherein the correction value can be subjected to adjustment corresponding to component variation of an antenna connected to the amplifier.   The transmission apparatus control device according to claim 1, wherein the correction value can be adjusted based on a reception state in a reception apparatus that receives a transmission signal from the antenna.   The transmission apparatus control device according to claim 1, further comprising a storage unit that stores the correction value.   The transmission device control device according to claim 1, wherein the control unit is realized by at least a part of a function of a microprocessor. A transmission device control device according to any one of claims 1 to 11,
A transmission circuit for outputting a data signal to the transmission device control device;
A wireless device comprising: a control circuit that controls at least one of the transmission device control device and the transmission circuit.   13. The wireless device according to claim 12, wherein the wireless device is at least one of a radio microphone, a transceiver, a cordless telephone, a computer peripheral device, a wireless speaker, a wireless microphone, a wireless medical device, an FM transmitter, an RF-ID device, and a wireless power supply device. Wireless equipment.

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