CN2775679Y - High frequency ground wave radar responsing device - Google Patents

Abstract

The utility model discloses a high-frequency ground wave radar response device based on frequency shift keying technology (that is, FSK technology), which is mainly composed of a receiving and delay circuit, a frequency source circuit, a signal restoration circuit, a power amplification and transmitting circuit and Synchronous control circuit structure, the response device sets the local oscillator frequency of receiving and transmitting through the computer, so that the frequency difference between the two can be adjusted between 0.2-0.7Hz, and provides a spectrum for the wide-beam radar to test the target signal arrival angle at 0.2 -The response signal that changes flexibly within the range of 0.7Hz.

Description

High frequency ground wave radar transponder

technical field

The utility model relates to a response device of a high-frequency ground wave radar for sea measurement with a wide beam, which belongs to the technical field of radar detection.

Background technique

At present, wide-beam high-frequency ground wave radar is widely used because of its simple antenna array, low cost and small footprint. However, the resolution of this type of radar to the target is mainly improved by software algorithms. The angle of arrival of the target signal, that is to say, to test the accuracy of the software algorithm, requires a known response signal. With this signal, the high-frequency ground wave can be detected on the sea or on land where conditions permit. The radar is calibrated and calibrated, so the wide-beam radar must be equipped with a transponder to calibrate the angle of arrival of the signal, and the frequency spectrum of the transponder is required to be flexibly changed within the range of 0.2-0.7Hz, while the signal sent by the existing transponder is A fixed frequency spectrum of 0.5 Hz cannot well meet the needs of wide-beam high-frequency ground wave radars for transponders, and the structure of existing transponders is also very complicated.

Contents of the invention

In order to overcome the deficiencies of the prior art, the utility model provides a high-frequency ground wave radar response device, which converts the received signal transmitted by the main radar station into an intermediate frequency signal and delays it for a fixed time before connecting to the recovery and transmission system. At the same time, a local oscillator frequency generator AD9854 is used to generate two local oscillator signals with different frequencies in the form of time division, and the identification signal is inserted into the transmitted signal, that is, the local oscillator frequency is changed during transmission so that the frequency of the transmitted signal is the same as that of the received signal. There is a frequency difference of 0.2-0.7Hz between the signal frequencies, so as to achieve the purpose of making the frequency difference between the two adjustable between 0.2-0.7Hz by changing the local oscillator frequency of receiving and transmitting.

The technical solution adopted by the utility model to solve the technical problems is: the high-frequency ground wave radar response device mainly includes a receiving and delaying circuit, a synchronous control circuit, a frequency source circuit, a signal restoring circuit, and a power amplification and transmitting circuit. The input of the timing circuit is the high-frequency signal of the radar master station, and the delay line output of the receiving circuit is connected with the signal restoration circuit; the signal of the frequency source circuit is output in two ways in the form of FSK (frequency shift keying), one is connected to the receiving and The delay circuit is connected with the signal recovery circuit; the three outputs of the synchronous control circuit are respectively connected with the receiving and delay circuit, the signal recovery circuit, the frequency source circuit and the power amplification and transmission circuit. Among them, the frequency source circuit is composed of the local oscillator frequency generator AD9854, a conventional chipset for selecting the frequency generated by AD9854, and conventional peripheral separation devices; the receiving and delay circuit is mainly composed of switch chip SA630, amplifier A06, filter SBP, mixing Frequency converter JMS-1MH, amplifier Gali52, delay line and conventional peripheral devices are connected. There are two switch chips SA630, which are respectively connected to the input and output of amplifier A06; the synchronous control circuit is mainly composed of EPM3256 and peripheral conventional separation devices. The three pulse signals are the transmission pulse signal (TP) and its inversion signal (NTP), and the ground pressure wave control pulse (TB); the power amplification and transmission circuit is mainly composed of two-stage amplifiers; the signal restoration circuit is mainly composed of amplifiers , Mixer ADE-1ASK, switch control chip SA630 and filter are connected.

The utility model uses the AD9854 chip to generate two signals with different frequencies, outputs them in the form of FSK (Frequency Shift Keying), and then separates them with a switch circuit, and sends them to the receiving component and the signal restoring component respectively, so that the transponder There is a frequency difference between the receiving frequency and the transmitting frequency, and the frequency difference can be adjusted between 0.2--0.7Hz through the computer. Because this signal is an identification signal added after the device receives the radar signal, we can easily distinguish the response signal from the ocean echo, and the geographic coordinates of the transponder are known, so it can be used to calibrate the same geographic coordinates ocean echoes. Moreover, if the device is placed anywhere in the detection area of the ground wave radar, the signal emitted by the radar can be received, and the signal can be amplified and sent back to the main radar station.

Description of drawings

Fig. 1 is a circuit block diagram of the utility model.

Fig. 2 is a receiving and delay circuit diagram of the utility model.

Fig. 3 is the frequency source circuit diagram of the utility model.

Fig. 4 is a signal restoration circuit diagram of the utility model.

Fig. 5 is the amplification and emission circuit diagram of the utility model.

Fig. 6 is a synchronous control circuit diagram of the utility model.

FIG. 7 is a schematic diagram of the timing relationship of signals in the synchronous control circuit of the present invention.

Detailed ways

As shown in Figure 1, the high-frequency ground wave radar response device provided by the utility model mainly includes a receiving and delay circuit 1, a synchronous control circuit 2, a frequency source circuit 3, a signal restoration circuit 4, and a power amplification and transmitting circuit 5. The input of the delay circuit 1 is the high-frequency signal of the radar master station, and the output of the delay line of the receiving circuit is connected to the signal restoration circuit 4; the signal of the frequency source circuit 3 is output in two ways in the form of FSK, and one is connected to the receiving and delaying circuit. Timing circuit 1, the other is connected to signal restoration circuit 4; the three outputs of synchronous control circuit 2 are respectively connected with receiving and delay circuit 1, signal restoration circuit 4, frequency source circuit 3 and amplification and transmitting circuit 5. The utility model is described in detail below with specific embodiment:

The receiving and delay circuit (see Figure 2) includes: switch chip SA630 (T1, T3), amplifier A06 (T2), filter SBP (T4), mixer JMS-1MH (T5), amplifier Gali52 (T6), 64μS delay line (T7) and its peripheral circuits. The high-frequency signal coming in from the antenna reaches pin 3 of the switch SA630 (T1) via J1. This switch is controlled by TB (from the synchronous control circuit). When TB is high, the input signal is transferred from the 8 The pin output is sent to A06 for amplification, and then passes through a switch SA630 (T3) again, and is input from pin 3 of SA630 (T3) and output from pin 8 under the control of TB. The two switches here can basically prevent the transmitted signal from entering the receiver. The signal output from T3 is input to SBP (T4) for filtering, then the signal output by T4 is input to JMS-1MH (T5) to mix with the local oscillator signal after passing through the attenuator composed of R3, R4, R5, and then the output signal of T5 is passed through C11 is amplified by Gali52 (T6) and sent to the delay line (T7) for 64μs delay. Finally, the output of the delay line is connected to a transformer T8 to match the impedance of the next circuit.

The frequency source circuit is shown in Figure 3, which mainly consists of MAX232(T9), 89C51(T10), SN74HC245(T11), SN74HC573(T12), SN74HC125(T13), local oscillator frequency generator AD9854(T14) and filter PLP (T15) is connected, and T14 is the main chip, adopts AD9854, can produce the signal of the specific frequency required by the utility model by it, the selection of its output frequency is by computer through chip T9——T15 it is written into appropriate control words to achieve. The specific working process can be described as follows: programmed by the computer, through the RS-232 interface——J3 in Figure 3, and then level-shifted by T9 to write data to 89C51 (T10), T10 according to the instruction through T11 data buffer, After the T12 address is latched, it is connected to the 1-8 feet and 14-19 feet of the AD9854, and the frequency control word and control command are sent to T14, and the output signal of T14 is sent out by J4 after passing through the band-pass filter T15. Here, by setting the frequency control word of AD9854 to make it work in the working state of FSK, use the TP signal generated by the synchronous control circuit to control the 29 pin of AD9854, when the 29 pin of T14 is low level, the output frequency of T14 is T14 The frequency corresponding to frequency control word 1, when pin 29 of T14 is at a high level, the output frequency of T14 is the frequency corresponding to frequency control word 2 of T14, and at the same time, when pin 29 of T14 is at a high level, the local oscillator is output to the transmitting component. When pin 29 of T14 is low level, the local oscillator is output to the receiving component. By setting the frequency control word of T14, the difference between the carrier frequency of the transmitted signal and the carrier frequency of the received signal is 0.5Hz or other frequencies (between 0.2-0.7Hz), so that the FSK method of transforming the local oscillator signal can be realized in the analog Add an identification signal to the target echo signal.

Response signal recovery circuit (see Figure 4) includes Gali52 (T16, T17) as the main component of the amplifier circuit, mixer ADE-1ASK (T18), switch control chip SA630 (T19), filter (T21). Local oscillator amplification is completed by T17. In Figure 3, the output signal of AD9854 is sent to pin 1 of T17 through C34, and then sent out from pin 3 after amplification, and then sent to T19 through C36. Connected to pin 1 of T18, one way is sent from pin 8 to JMS-1MH (T5 in Figure 2) in the receiving circuit. When the signal NTP of the control switch is low, the local oscillator signal is sent to 1 of mixer T18 pin, when the signal NTP of the control switch is high, the local oscillator signal is sent to pin 1 of T5 in the receiver circuit. The signal output by mixing frequency is sent out from pin 5, after frequency selection by band-pass filter T21 at the back, the difference frequency signal is taken out, that is, the received signal is restored. Assume that the frequency of the signal received by the antenna of the receiver is f1, the local oscillator frequency is F when receiving, the local oscillator frequency is F+0.5Hz when restoring, and the frequency output by the restoring circuit is f2, that is, the intermediate frequency output by the receiver is:

     f = F-f1 = 4.43MHz

     f2＝F+0.5-(F-f1)＝(f1+0.5)Hz

The power amplifying and transmitting circuit (as shown in Figure 5) includes two-stage amplifying circuits based on A06 (T22) and RF2317 (T23) and two-stage amplifying circuits based on 9014 (T25, T26), A966 (T27), 9014 (T28, T29) , A966 (T30) as the main emission control component, the control pulse is added to the b pin of T25 through R64, when the pulse arrives, T25, T26, T27 are all turned on, the 9V power supply is supplied to T22 through T27, T22 has output, pulse When not coming, above-mentioned T25, T26, T27 all end, and T22 also has no signal to send.

T22 and T23 amplify the signal, T23 uses the RF2317 component, the signal output by T22 is sent to the 4th pin of T23 through C59, the signal amplified by T23 is sent out from the 13th pin, after passing through the band-pass filter T24 at the back, it is sent through J10 Go to the switching circuit of the common antenna for sending and receiving. Here, T28, T29, T30 are used to control the bias voltage of RF2317. When the pulse is added to T28 via R68, T28, T29, and T30 are all turned on, and the 12V power supply is supplied to T23 through T30, and T23 has an output. When the pulse does not come, the above-mentioned T28, T29, T30 are all cut off, and there is no signal sent from T23.

The synchronous control circuit is shown in Figure 6. The T34 in the figure is designed by the EPM3256 in the MAX3000 series chip of ALTER Company, which generates three pulse signals: the transmission pulse (TP); the inverse signal of the transmission pulse (NTP); Wave Pulse (TB). Their waveform diagram and timing relationship are shown in Figure 7. Transmit when TP is high level, receive when TB is high level.

Claims (7)

1. A high-frequency ground wave radar response device is characterized in that: the device at least includes receiving and delay circuit, frequency source circuit, signal restoration circuit, power amplification and transmitting circuit and synchronous control circuit, receiving and the input of delay circuit For the high-frequency signal of the radar master station, the delay line output of the receiving circuit is connected to the signal restoration circuit; the signal of the frequency source circuit is output in two ways in the form of FSK, one is connected to the receiving and delay circuit, and the other is connected to the signal restoration circuit ; The three outputs of the synchronous control circuit are respectively connected with the receiving and delaying circuit, the signal restoration circuit, the frequency source circuit and the power amplification and transmitting circuit. 2. The high-frequency ground wave radar response device according to claim 1, characterized in that: the frequency source circuit is composed of local oscillator frequency generator AD9854 and a conventional chipset for selecting the frequency generated by AD9854, and conventional peripheral separation devices. 3. The high-frequency ground wave radar response device according to claim 1 or 2, characterized in that: the frequency source circuit mainly consists of MAX232, 89C51, SN74H245, SN74HC573, SN74HC125, local oscillator frequency generator AD9854, and filter PLP chip Connected, AD9854 is the main chip. 4. The high-frequency ground wave radar response device according to claim 1 or 2, characterized in that: receiving and delay circuit are mainly composed of switch chip SA630, amplifier A06, filter SBP, mixer JMS-1MH, amplifier Gali52 , delay line and conventional peripheral devices are connected. There are two switch chips SA630, which are respectively connected to the input and output of the amplifier A06. 5. according to claim 1 or 2 described high-frequency ground wave radar answering devices, it is characterized in that: the synchronous control circuit is mainly made of EPM3256 and peripheral conventional separation device, produces 3 pulse signals altogether and transmits pulse signal (TP) and Its inversion signal (NTP), and ground pressure wave control pulse (TB). 6. The high frequency ground wave radar response device according to claim 1 or 2, characterized in that the signal restoration circuit is mainly composed of an amplifier, a mixer ADE-1ASK, a switch control chip SA630 and a filter. 7. The high-frequency ground wave radar response device according to claim 1 or 2, characterized in that: the power amplifying and transmitting circuit mainly consists of two-stage amplifying circuits.

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