CN205450261U - Calibration source device based on high frequency over --horizon radar - Google Patents

Abstract

The utility model discloses a calibration source device based on high frequency over - -horizon radar, including power supply circuit, GPS circuit, receiving circuit, transmitting circuit and FPGA circuit: power supply circuit includes solar energy receiving module and electric power storage module, the GPS circuit is including constant temperature crystal oscillator, GPS signal reception module and synchronization module, receiving circuit is including the receiving antenna, transmitter -receiver isolation switch, wave filter and the AD converter that connect gradually, the transmitting circuit is including the DA converter, wave filter, transmitter -receiver isolation switch, power module and the emit antenna that connect gradually, the FPGA circuit is connected with GPS circuit, AD converter, DA converter, transmitter -receiver isolation switch and power module respectively. The utility model discloses can analyze radar transmission signal automatically to producing according to radar work agreement and corresponding the calibrating signal, have that the circuit is simple, the low power dissipation, stability is high, with low costs and be suitable for field work's advantage, specially adapted high frequency over -the -horizon radar calibrates.

Description

A calibration source device based on high-frequency over-the-horizon radar

technical field

The utility model relates to a calibration source device based on high-frequency over-the-horizon radar, which belongs to the technical field of high-frequency over-the-horizon radar.

Background technique

High-frequency over-the-horizon radar has been widely used to detect dynamic parameters such as sea surface wind, waves and currents, and can also be used to detect sea surface ships and low-speed flying targets. There are amplitude and phase errors in the radar receiving array, which will affect the detection performance of the radar. Commonly used calibration methods are divided into passive calibration and active calibration. The active calibration method needs to place a calibration source in the far field, and realize the radar receiving array calibration through some active calibration methods. For example, the Chinese invention patent "a method based on inter-station direct wave interference Array phase error calibration method" (Patent No.: CN201110439090.0). The existing calibration equipment has a complex structure, high power consumption, and mostly uses an external power supply structure and cannot analyze radar transmission signals, which cannot meet the work requirements of isolated islands and other places without power supply.

Utility model content

In view of the above problems, the purpose of this utility model is to provide a calibration source device based on high-frequency over-the-horizon radar.

To achieve the above object, the utility model takes the following technical solutions:

A calibration source device based on high-frequency over-the-horizon radar, including a power supply circuit, a GPS circuit, a receiving circuit, a transmitting circuit and an FPGA circuit; the power supply circuit includes a solar receiving module and an electric energy storage module; the GPS circuit includes a constant temperature crystal oscillator, a GPS signal receiving module and Synchronization module; the transmitting circuit includes sequentially connected D/A converters, filters, transceiver isolating switches, power modules and transmitting antennas; the receiving circuit includes sequentially connected receiving antennas, transmitting and receiving isolating switches, filters and A/D converters; The FPGA circuit is respectively connected with the GPS circuit, A/D converter, D/A converter, transceiver isolating switch and power module; the GPS circuit (10) is respectively connected with the A/D converter (9), D/A converter (4 )connect.

The GPS circuit (10) generates a corresponding synchronization signal consistent with the working sequence of the radar to ensure that the calibration source device and the radar are synchronized, and generates a corresponding calibration signal through the transmitting circuit (5) and transmits it under this sequence; the GPS signal receiving module Receive the GPS signal, and the constant temperature crystal oscillator provides a system working clock with high stability, low jitter and low phase noise; the 1PPS signal obtained by taming the clock signal of GPS and its frequency division; after that, the synchronization module generates the radar synchronization control sequence, so that the calibration source device Synchronized with radar work.

The transmitting circuit generates a calibration signal under the control of the synchronous signal generated by the GPS, amplifies and controls the power through the power module, and finally transmits it through the transmitting antenna.

The receiving circuit receives the radar transmission signal, and after digitization, mixes it with local oscillator signals of different center frequencies within the radar working bandwidth to obtain the radar working frequency.

The power supply circuit can convert solar energy into electric energy and store it, and the device can work in a field environment without electric power supply.

Due to the adoption of the above technical scheme, the utility model has the following advantages: it can automatically analyze the radar transmission signal and generate a corresponding calibration signal, and has the advantages of simple circuit, low power consumption, high stability, low cost and suitable for field work, especially Suitable for high-frequency over-the-horizon radar calibration.

Description of drawings

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

Among them, 1—power module, 2—transmitting isolating switch 1, 3—filter, 4—D/A converter, 5—transmitting circuit, 6—FPGA circuit, 7—transceiving isolating switch 2, 8—filter, 9 —A/D converter, 10—GPS circuit, 11—receiving circuit, 12—power supply circuit.

detailed description

Below in conjunction with accompanying drawing and embodiment the utility model is described in detail.

In this embodiment, the high-frequency over-the-horizon radar works in the FMICW system, the sweep frequency bandwidth and sweep cycle remain unchanged, the radar operating frequency accuracy is 1KHz, the radar operating timing is determined, and the participating radars are synchronized through GPS.

As shown in Figure 1, the utility model includes a power supply circuit (12), a GPS circuit (10), a receiving circuit (11), a transmitting circuit (5) and an FPGA circuit (6): the power supply circuit (12) includes a solar receiving module and Electric energy storage module; GPS circuit (10) includes a constant temperature crystal oscillator, GPS signal receiving module and synchronization module; transmitting circuit (5) includes sequentially connected D/A converter (4), filter (3), and a transceiver isolating switch ( 2), the power module (1) and the transmitting antenna; the receiving circuit (11) includes the receiving antenna connected in sequence, the transceiver isolating switch 2 (7), the filter (8) and the A/D converter (9); the FPGA circuit ( 6) Connect with GPS circuit (10), A/D converter (9), D/A converter (4), transceiver isolation switch 1 (2), transceiver isolation switch 2 (7) and power module (1) ; The GPS circuit (10) is connected to the A/D converter (9) and the D/A converter (4) respectively.

The power supply circuit (12) can convert solar energy into electric energy and store it, and the power supply circuit (12) supplies power to the whole device, which can ensure that the calibration device works in the field environment without power supply.

The receiving circuit (11) receives the radar transmission signal through the receiving antenna, and then connects to the transceiver isolating switch 2 (7), and after filtering by the filter (8), connects to the A/D converter (9) for sampling and digitization. Wherein, the isolation degree of the transceiver isolating switch (7) is greater than 60dB, the transmitting and receiving isolating switch two (7) is opened when the radar is transmitting, and the transmitting and receiving isolating switch two (7) is closed when the radar is receiving. The center frequency and bandwidth of the filter (8) are consistent with the radar working bandwidth, and signals outside the radar working bandwidth are suppressed as much as possible. The A/D converter (9) integrates a signal gain circuit inside, which can provide a gain control of -10dB~40dB, and can ensure that the calibration device works in the best state. The receiving circuit is based on the idea of "software radio". The circuit structure is simple, the power consumption is low, and the sensitivity is high, which can meet the actual work requirements.

The FPGA circuit (6) generates local oscillator signals of different center frequencies within the radar operating bandwidth, and performs frequency mixing with the digital signal sampled by the A/D, and the mixed signal is connected to a digital low-pass filter for filtering, The passband frequency of the low-pass filter is 100Hz, and the stopband cut-off frequency is 150Hz, and the output signal energy is counted. Therefore, the power distribution of the received signal under different frequency local oscillator signals can be obtained, and the radar operating frequency can be obtained by determining the maximum power. The FPGA circuit can analyze the radar transmission signal in real time and provide relevant information to the transmission circuit.

The GPS circuit (10) receives GPS signals by a GPS signal receiving module, and the constant temperature crystal oscillator provides a system working clock with high stability, low jitter and low phase noise, and the frequency is 10MHz. The 1PPS signal obtained by taming the 10MHz clock and its 100,000 frequency division through GPS. Afterwards, the radar synchronous control sequence is generated by the synchronous module, so that the calibration source device and the radar work synchronously.

The transmitting circuit (5) generates a calibration signal according to the radar signal information analyzed by the receiving circuit (11), and the calibration signal adopts a Chinese invention patent "a method for realizing simultaneous multi-frequency transmission/reception of ground wave over-the-horizon radar" ( The phase offset method described in the patent number: ZL201410014040.1) simulates the movement of the target. This method can cause the calibration signal to generate Doppler shift, so that the calibration signal is separated from the ocean echo signal and the target echo signal. The generated calibration signal is connected to the filter (3) for filtering, and the filtered signal is connected to the transceiver isolating switch one (2), then amplified and controlled by the power module (1), and finally transmits the signal through the transmitting antenna. Among them, the isolation degree of the transceiver isolating switch one (2) is greater than 60dB, the transmitting and receiving isolating switch one (2) is closed when the radar is transmitting, and the transmitting and receiving isolating switch one (2) is opened when the radar is receiving. The enabling of the power module (1) is consistent with that of the transceiver isolation switch one (2), that is, the power module (1) stops working when the transceiver isolation switch one (2) is turned off, and the power module (1) is turned on when the transceiver isolation switch one (2) is turned on. work, which reduces the power consumption of the calibration setup. The center frequency and bandwidth of the filter (3) are consistent with the radar working bandwidth.

Due to the adoption of the above technical scheme, the utility model can automatically analyze the radar transmission signal and generate a corresponding calibration signal. It has the advantages of simple circuit, low power consumption, high stability, low cost and suitable for field work, and is especially suitable for high-frequency over-the-horizon Radar calibration. The methods utilized in the utility model all belong to the prior art, and the utility model is aimed at innovation and protection of hardware.

Claims (4)

1. a calibration source device based on high frequency over the horizon radar, it is characterised in that: include power circuit (12), GPS circuitry (10), receive circuit (11), radiating circuit (5) and FPGA circuitry (6)；Described radiating circuit (5) includes the D/A converter (4) being sequentially connected with, wave filter (3), transceiver insulation switch one (2), power model (1) and launches antenna；Described reception circuit (11) includes reception antenna, transceiver insulation switch two (7), wave filter (8) and the A/D converter (9) being sequentially connected with；FPGA circuitry (6) is connected with GPS circuitry (10), A/D converter (9), D/A converter (4), transceiver insulation switch one (2), transceiver insulation switch two (7) and power model (1) respectively；GPS circuitry (10) is connected with A/D converter (9), D/A converter (4) respectively.

A kind of calibration source device based on high frequency over the horizon radar the most according to claim 1, it is characterised in that: described GPS circuitry (10) includes constant-temperature crystal oscillator, gps signal receiver module and synchronization module；GPS circuitry (10) produces the corresponding synchronizing signal consistent with radar work schedule, it is ensured that calibration source device and radar synchronize, and emitted circuit (5) produces correspondence calibration signal and launches under this sequential.

A kind of calibration source device based on high frequency over the horizon radar the most according to claim 2, it is characterised in that: described power circuit (12) includes solar energy receiver module and electric energy memory module；Power circuit (12) converts the solar into electric energy and stores, it is ensured that this calibration source device is operated in the wild environment of unregulated power supply.

A kind of calibration source device based on high frequency over the horizon radar the most according to claim 3, it is characterized in that: described reception circuit (11) receives radar emission signal, the local oscillation signal of the different center frequency produced with FPGA circuitry (6) after digitized is mixed, and obtains radar operating frequency.