JPH11274827A - Radio equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To satisfactorily perform communication under a wider range of radio wave conditions. SOLUTION: A terminal connected with one terminal part of the coil-shaped conductor 14b of a miniaturized antenna 14 is provided with a small gap from in power feeding terminal 13a of an antenna 13. A terminal connected with the other terminal part of the conductor 14b is connected to a radio part 15. The antenna 13 and the radio part 15 are matched by the miniaturized antenna 14. A gain can be improved with characteristics similar to a bottom loading monopole antenna by turning the center axis of the coil-shaped conductor 14b in the direction of an arrow A almost the same as the central axis of the antenna 13. When the central axis of the conductor 14b and the central axis of the antenna 13 are in different directions, polarization diversity reception is enabled.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a wireless device. More specifically, matching between a first antenna for transmitting or receiving radio waves and a radio unit for generating a transmission signal of a predetermined frequency or processing a received signal is performed using a second antenna.

[0002]

2. Description of the Related Art Conventionally, a portable wireless device, for example, a portable telephone 40, is provided with an antenna 13 for transmitting or receiving radio waves as shown in FIG. A transmission signal is generated by the radio unit 15. The wireless unit 15 also performs processing of a received signal obtained by receiving a radio wave with the antenna 13.

In this radio apparatus, the antenna 13 is, for example, a half-wavelength antenna to reduce the influence of the human body or the like to efficiently radiate radio waves or to prevent the mobile phone 40 from being affected by the radiated radio waves. By using the monopole antenna, the maximum current point of the antenna 13 is separated from the main body of the mobile phone 40.

Here, the feeder terminal 13a at the end of the antenna 13 which is a half-wavelength monopole antenna has a high impedance, and the output stage of the transmission signal in the radio unit 15 or the input stage of the reception signal. The impedance is set to a predetermined impedance (for example, 50Ω), and the antenna 13 and the radio unit 15 have different impedances. For this reason, a matching circuit 41 is provided to match the impedance between the antenna 13 and the radio unit 15 and prevent a decrease in gain due to reflection loss. One terminal of the matching circuit 41 is a power supply terminal 13a of the antenna 13.
Are provided at a small interval (for example, about 1 mm) and C-coupled. The other terminal is connected to the radio unit 15.

[0005]

By the way, in such a portable radio device, a radio wave state which can be dealt with is determined by the directivity of the antenna 13, so that good communication is performed when the radio wave condition changes. In some cases, it is not possible.

In view of the above, the present invention provides a wireless device capable of performing good communication by expanding the range of radio wave conditions that can be handled.

[0007]

A radio apparatus according to the present invention includes a first antenna for transmitting or receiving a radio wave, a radio section for generating a transmission signal of a predetermined frequency or processing a reception signal, and a radio section for transmitting a radio wave. Alternatively, it has a second antenna for receiving and matching the first antenna with the radio section.

In the present invention, for example, a monopole antenna having approximately a half wavelength is used as the first antenna, and a radio unit for generating a transmission signal of a predetermined frequency or processing a reception signal with the first antenna is used. Is performed by a second antenna configured using, for example, a coiled conductor. Further, the first and second antennas are provided in the wireless device such that the polarization plane of the first antenna is different from the polarization plane of the second antenna.

[0009]

Next, an embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 is a diagram showing the appearance of a portable wireless device, for example, a mobile phone. In FIG. 1, an approximately half-wavelength antenna 1 composed of a linear conductor is provided at the upper end of a main body 11 of a mobile phone 10.
3 is provided so as to be able to be pulled out from the main body 11. Further, a voice passage hole 31 for guiding voice from a built-in speaker (receiver) 19 above the main body 11 to the outside is formed, and a display unit 24 is arranged below the voice passage hole 31. Furthermore, body 1
A microphone (speaker) 20 is arranged below 1. In addition, a key input unit 23 is arranged below the display unit 24 in the center of the main body 11. Further, on the side surface of the main body 11, a volume adjustment key for adjusting the volume is arranged.

FIG. 2 shows the configuration of a portable telephone. The mobile phone 10 includes a microcomputer 12 (hereinafter, referred to as “microcomputer”) for controlling the operation of the mobile phone.
Antenna 13 for transmitting and receiving, small antenna 14 for performing impedance matching while transmitting and receiving radio waves, antenna 13
And a down-converted reception signal of a predetermined frequency received by the small antenna 14 to π / 4 shift QPSK (Quadra
and a π / 4 shift QP output from a digital modulation / demodulation unit to be described later.
A radio unit 15 for up-converting the SK signal to obtain a transmission signal of a predetermined frequency; demodulating a π / 4 shift QPSK signal output from the radio unit 15 to obtain reception data; (Time Division
And a digital modulation / demodulation unit 16 for performing modulation processing on transmission data output from a MultipleAccess) processing unit to obtain a π / 4 QPSK signal.

The mobile phone 10 selects predetermined downlink slot data from the received data (time-division multiplexed data of a plurality of slots) output from the digital modulation / demodulation unit 16 and separates the data into control data and compressed audio data. In addition, a TDMA for multiplexing compressed audio data output from an audio codec unit to be described later and control data output from the microcomputer 12 into a preset uplink slot.
It has a processing unit 17.

The portable telephone 10 performs a decoding process (including an error correction process) on the compressed voice data output from the TDMA processing unit 17 to obtain a received voice signal, A voice codec section 18 for performing compression coding processing (including an error correction code addition processing) to obtain compressed voice data;
Speaker 1 to which the received audio signal output from 8 is supplied
9 and a microphone 20 for supplying a transmission audio signal to the audio codec section 18.

The portable telephone 10 has a DTMF (Dual T
a DTMF modulation / demodulation unit 21 which converts the key data outputted from the microcomputer 12 into a DTMF signal and supplies it to the audio codec unit 18 as a transmission audio signal. And a conversion format storage unit 22 for converting the key data output from the DTMF modulation / demodulation unit 21 into character data. The conversion format storage unit 22 is connected to the microcomputer 12.

The portable telephone 10 has a key input unit 23 operated for setting various operations and making a call. The key input unit 23 is connected to the microcomputer 12, and the microcomputer 12 monitors key operations of the key input unit 23. Further, it has a display unit 24 using a liquid crystal display (LCD) for displaying an operation state and various information. Although not shown, the mobile phone 10 is also provided with a memory for storing telephone numbers and the like, a ring tone output unit for outputting a ring tone, and the like.

Here, as shown in FIG. 3, the small antenna 14 is provided on the outer peripheral surface of a base material 14a such as ceramics.
The conductor is formed by a method such as vapor deposition so that the coil is wound, and the conductor length of the coil-shaped conductor 14b is approximately one.
/ 4 wavelength. One end of the coiled conductor 14b is connected to the terminal 14c, and the other end is connected to the terminal 1c.
4d.

FIG. 4 shows a state in which the small antenna 14 is attached. One terminal 14 of the small antenna 14 is shown.
c (14d) is provided at a slight distance (for example, about 1 mm) from the power supply terminal 13a of the antenna 13, and is C-coupled. The other terminal 14d (14c) is connected to the radio unit 15. Further, the central axis of the coiled conductor 14b of the small antenna 14 is set to a direction substantially equal to the central axis of the antenna 13 (the direction indicated by the arrow A in the figure). In this case, the same characteristics as the bottom loading monopole antenna can be obtained by the antenna 13 and the small antenna 14.

Here, as shown in FIG.
When the and small antenna 14 are C-coupled, the current distribution is as shown in FIG. 3B. Note that FIG.
In B, the dashed line indicates the current based on the image.
Further, as shown in FIG. 3C, the directivity has a figure-shaped characteristic having a peak in the horizontal direction. here,
Since the directivity of the half-wavelength monopole antenna is a characteristic indicated by a broken line in FIG. 3C, the beam width can be narrowed by using the small antenna 14, and the antenna gain can be increased.

By the way, in the case shown in FIG. 4, the planes of polarization of the antenna 13 and the small antenna 14 are assumed to be the same, but as shown in FIG. If the small antenna 14 is mounted so that the central axis of 14b is in a different direction (for example, the direction of arrow B in the figure), the polarization planes of the antenna 13 and the small antenna 14 are different. For this reason, polarization diversity reception can be performed by the antenna 13 and the small antenna 14, and good communication can be performed even if radio waves are reflected and the polarization plane changes.

As described above, according to the above-described embodiment,
By providing the small antenna 14, the antenna 13 and the radio unit 15 can be matched, and the gain can be increased and the polarization diversity reception can be performed. It can be performed.

In the above-described embodiment, the case where the wireless device is a mobile phone has been described. However, it goes without saying that the wireless device is not limited to the mobile phone.

[0021]

According to the present invention, since the matching between the first antenna and the radio section is performed using the second antenna, it is possible to prevent a decrease in gain due to reflection loss,
Since two antennas are used, it is possible to extend a range of a radio wave state that can be supported and perform favorable communication.

Further, by forming the first antenna with a linear conductor and forming the second antenna with a coil-shaped conductor, the gain of the antenna is increased as compared with a conventional radio apparatus using only the first antenna. be able to. Also,
Since the polarization plane of the first antenna and the polarization plane of the second antenna are provided so as to be different from each other, it is possible to perform polarization diversity reception, and to receive the radio wave well even if the polarization plane of the radio wave is changed by reflection or the like. can do.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating an appearance of a mobile phone.

FIG. 2 is a diagram illustrating a configuration of a mobile phone.

FIG. 3 is a diagram showing a configuration of a small antenna.

FIG. 4 is a diagram showing a mounting state of a small antenna.

FIG. 5 is a diagram illustrating characteristics of a bottom-loading monopole antenna.

FIG. 6 is a diagram showing another mounting state of the small antenna.

FIG. 7 is a diagram showing a conventional configuration.

[Explanation of symbols]

 10, 40 mobile phone 13 antenna 14 small antenna 14 b coiled conductor 15 radio section

Claims (3)

[Claims] A first antenna for transmitting or receiving a radio wave; a radio unit for generating a transmission signal of a predetermined frequency or processing a received signal; a radio unit for transmitting or receiving a radio wave, and the first antenna and the radio A wireless device comprising a second antenna for matching with a unit. 2. The wireless device according to claim 1, wherein the first antenna is formed of a linear conductor, and the second antenna is formed of a coiled conductor. 3. A polarization plane of the first antenna and the second antenna.
The wireless device according to claim 2, wherein the first antenna and the second antenna are provided such that the polarization planes of the antennas are different.