Continuous wave radar receiving and transmitting system
Technical Field
The utility model belongs to the technical field of the radar, in particular to are in succession by radar send-receiver system.
Background
In recent years, with the development of small unmanned aerial vehicles, airborne radars which fly at low altitude and have a short range of action have attracted much attention. In order to meet the requirements of platform mounting, the radar needs to realize high integration, miniaturization, light weight and low power consumption of a system on the premise of unchanged performance, and can be flexibly mounted on various platforms. The continuous wave radar has light weight, small volume and low power consumption, but the receiving and transmitting antennas of the continuous wave radar work simultaneously and the two antennas are closely spaced, the leakage of the transmitting signal to the receiving channel is serious, and the problem of receiving, transmitting and isolating is always a main factor for limiting the application and development of the continuous wave radar.
Because the receiving and transmitting antennas of the continuous wave radar work simultaneously and the two antennas are closely spaced, the leakage of the transmitting signal to the receiving channel is serious. First, strong leakage signals saturate the amplifier, and even saturate the mixer and low noise amplifier. Secondly, leakage of transmitter noise to the receiver will cause the receiver to be desensitized. Third, false doppler signal generation may be caused by the presence of leakage.
The traditional radar always takes a pulse system radar as a main part, and the reason is that in a single-station radar with a transmitting and receiving shared antenna, although a transmitting and receiving switch can be adopted by the pulse radar, the isolation of transmitting pulses and receiving pulses can be conveniently realized in a time domain, but the defects of the pulse radar, such as complex equipment, large volume, heavy weight, high requirement on a load platform and the like, are increasingly highlighted.
SUMMERY OF THE UTILITY MODEL
The utility model discloses an overcome the big, heavy and poor shortcoming of integrated level of system size, provided a radar send-receive system that the size is little, light in weight, high integration.
The utility model provides a continuous wave radar receiving and dispatching system draws together signal receiving and dispatching link and power supply control link, signal receiving and dispatching link includes transmitting link, reference source link, declivity link, receiving link, and the reference source link is connected with transmitting link, declivity link and receiving link respectively, and the declivity link still is connected with the receiving link, power supply control link is the power supply of signal receiving and dispatching link.
Further, the transmission link comprises a first transmission link baseband input SMA interface, a second transmission link baseband input SMA interface, a transmission link output SMA interface, a first baseband low-pass filter, a second baseband low-pass filter, a first video amplifier, a second video amplifier, an IQ modulator, a first band-pass filter, a first radio-frequency amplifier and a second band-pass filter;
the input end of the first baseband low-pass filter is connected with the baseband input SMA interface of the first transmission link, the output end of the first baseband low-pass filter is connected with the first input end of the IQ modulator through a first video amplifier, the input end of the second baseband low-pass filter is connected with the baseband input SMA interface of the second transmission link, the output end of the second baseband low-pass filter is connected with the second input end of the IQ modulator through a second video amplifier, the third input end of the IQ modulator is connected with the reference source link, the output end of the IQ modulator is connected with the input end of the second band-pass filter through the first band-pass filter and the first radio frequency amplifier, and the output end of the second band-pass filter is connected with the output SMA interface of the transmission link.
Further, the reference source link comprises a constant temperature crystal oscillator, a first amplifier, a first SRD frequency multiplier, a microstrip filter, a second radio frequency amplifier, a first power divider, a first acoustic meter filter, a second amplifier, a second power divider, a third amplifier, a fourth amplifier, a second acoustic meter filter, a second SRD frequency multiplier, a fifth amplifier, a third power divider, a 9.6GHz local array output interface, a 1.6GHz down-conversion local array output interface, an AD clock output interface, a DA clock output interface, and a receiving-demodulating local array output interface;
the constant temperature crystal oscillator is connected with the input end of a first power divider through a first amplifier and a first SRD frequency multiplier, the first output end of the first power divider is connected with the input end of a second power divider through a first sound meter filter and a second amplifier, the second output end of the first power divider is connected with an AD clock output interface through a second sound meter filter and a third amplifier, the first output end of the second power divider is connected with a 1.6GHz down-conversion local array output interface through a fourth amplifier, the 1.6GHz down-conversion local array output interface is connected with a deskew link, the second output end of the second power divider is connected with a 9.6GHz local array output interface through a fifth amplifier, a second SRD frequency multiplier, a microstrip filter and a second radio frequency amplifier, the 9.6GHz local array output interface is connected with the third input end of an IQ modulator, the third output end of the second power divider is connected with the input end of the third power divider, and a first output end and a second output end of the third power divider are respectively connected with the DA clock output interface and the receiving demodulation local array output interface, and the receiving demodulation local array output interface is connected with the receiving link.
Further, the deskew link comprises a second band-pass filter, a first mixer, a third band-pass filter and a third radio frequency amplifier;
the second band-pass filter is connected with the first input end of the first frequency mixer, the second input end of the first frequency mixer is connected with the 1.6GHz down-conversion local array output interface, the output end of the first frequency mixer is connected with the input end of the fifth radio-frequency amplifier through the third band-pass filter, and the output end of the third radio-frequency amplifier is connected with the receiving link.
Further, the receiving link comprises a first receiving link baseband output SMA interface, a second receiving link baseband output SMA interface, a third video amplifier, a fourth bandpass filter, a fifth bandpass filter, an IQ demodulator, an MGC gain controller, a sixth amplifier, a sixth bandpass filter, a second mixer, a seventh bandpass filter and a receiving link input SMA interface;
the first receiving link baseband output SMA interface is connected with the first output end of the IQ demodulator through a third video amplifier and a fourth bandpass filter, the second receiving link baseband output SMA interface is connected with the second output end of the IQ demodulator through a fourth video amplifier and a fifth bandpass filter, the first input end of the IQ demodulator is connected with the receiving demodulator local array output interface, the second input end of the IQ demodulator is connected with the output end of the second mixer through an MGC gain controller, a sixth amplifier and a sixth bandpass filter, the first input end of the second mixer is connected with the receiving link input SMA interface through a seventh bandpass filter, and the second input end of the second mixer is connected with the output end of the third RF amplifier.
Further, the power supply/monitoring link comprises a power supply module, a secondary power supply conversion module, a monitoring module, a power supply interface, a feedthrough capacitor power supply interface, a jumper and a power supply output interface;
the power supply interface is connected with the input end of the power supply module, the output end of the power supply module is connected with the input end of the secondary power supply conversion module, the first output end of the secondary power supply conversion module is connected with the feed-through capacitor power supply interface, the second output end of the power supply module is connected with the power supply output interface, the input end of the monitoring module is connected with the jumper wire, and the feed-through capacitor power supply interface and the jumper wire are both connected with the signal transceiving link.
The utility model discloses following beneficial effect has:
the utility model discloses a system design can effectively restrain continuous wave radar and receive transmitting antenna receiving and dispatching near-end and reveal the interference, keeps apart the signal suppression to the degree of enough lowly revealing effectively through receiving and dispatching, wherein, the receiving link has adopted frequency modulation (dechirp) to intermediate frequency then carries out the receiving method of baseband demodulation to the intermediate frequency, realizes the selection to useful signal at the intermediate frequency, realizes revealing the effective suppression of interference to the receiving and dispatching near-end at baseband filtering. The transmitting link adopts a direct orthogonal debugging transmitting link, and has simple design, few devices and low cost; coupling one path of transmitting signals of the transmitting link with a reference source local array signal for frequency mixing, and generating one path of down-conversion signals as deskew local array signals of the receiving link; the reference source module generates various working frequencies by taking a reference frequency as a reference in a comb spectrum mode, and performs gating by a filter to generate a fully coherent clock with high frequency stability and low phase noise and a local array signal; the system power supply and monitoring module provides a secondary power supply for the whole system, and simultaneously generates a remote measuring signal of a radio frequency part, and the power supply adopts a feedthrough capacitor to supply power for the radio frequency.
The system integrates the transmitting link, the receiving link, the reference source link and the power supply monitoring module, has complete functions, compact structure, small volume and light weight, reduces the assembly complexity of the whole machine, and has good stability and reproducibility.
Drawings
Fig. 1 is a schematic diagram of the block components of the present invention;
fig. 2 is a schematic block diagram of the transmit chain principle of the present invention;
FIG. 3 is a schematic block diagram of the deskew link principle of the present invention;
fig. 4 is a schematic block diagram of the reference source link principle of the present invention;
fig. 5 is a schematic block diagram of the receive chain principle of the present invention;
fig. 6 is a schematic block diagram of the principle of the power supply monitoring link of the present invention;
FIG. 1 depicts in notation: 1-transmitting link, 2-deskewing link, 3-reference source link, 4-receiving link, 5-power supply monitoring link, 6-first transmitting link baseband input SMA interface, 7-second transmitting link baseband input SMA interface, 8-transmitting link output SMA interface, 9-deskewing link input SMA interface, 10-receiving link input SMA interface, 11-first receiving link baseband output SMA interface, 12-second receiving link baseband output SMA interface, 13-power supply interface, 14-feedthrough capacitor power supply interface, 15-jumper, 16-power supply output interface;
FIG. 2 depicts in notation: 201-a first baseband low pass filter, 202-a second baseband low pass filter, 203-a first video amplifier, 204-a second video amplifier, 205-an IQ modulator, 206-a first band pass filter, 207-a first radio frequency amplifier, 208-a second band pass filter;
FIG. 3 depicts in notation: 301-a third band-pass filter, 302-a first mixer, 303-a fourth band-pass filter, 304-a third radio frequency amplifier;
FIG. 4 depicts a reference: 401-constant temperature crystal oscillator, 402-first amplifier, 403-second SRD frequency multiplier, 404-microstrip filter, 405-second radio frequency amplifier, 406-first power divider, 407-first sound table filter, 408-second amplifier, 409-second power divider, 410-fourth amplifier, 411-third amplifier, 412-second sound table filter, 413-first SRD frequency multiplier, 414-fifth amplifier, 415-third power divider, 416-9.6GHz local array output, 417-1.6GHz down-conversion local array output, 418-AD clock output, 419-DA clock output, 420-receiving and demodulating local array output;
FIG. 5 depicts a reference: 501-a third video amplifier, 502-a fifth band-pass filter, 503-a fourth video amplifier, 504-a sixth band-pass filter, 505-an IQ demodulator, 506-an MGC gain controller, 507-a sixth amplifier, 508-a seventh band-pass filter, 509-a second mixer, 510-an eighth band-pass filter;
FIG. 6 depicts in notation: 601-power module, 602-secondary power conversion module, 603-monitoring module;
Detailed Description
Referring to the description of the drawings, the utility model relates to a continuous wave radar transceiver system (see fig. 1), mainly include transmission link 1, anticline link 2, reference source link 3, receiving link 4 and power supply monitoring link 5: the first transmitting link baseband input SMA interface 6 and the second transmitting link baseband input SMA interface 7 of the transmitting link are both connected with a digital DA signal, and the transmitting link output SMA interface 8 is connected with a power amplifier module; the deskew link is connected with the emission coupling reference signal through a deskew link input SMA port 9; the clock generated by the reference source link is connected with the local array signal through the microstrip line and the connector between the boards; the receiving link is connected with the digital AD through a first receiving link baseband output SMA interface 11 and a second receiving link baseband output SMA interface 12, and is also connected with an external low-noise amplifier through a receiving link input SMA interface 10; the power supply monitoring link is connected with a power supply system through a power supply interface 13, supplies power to other links through a power supply feedthrough capacitor power supply interface 14, is connected with a monitoring signal through a jumper 15, and supplies power to an external power amplifier and a low-noise amplifier through a power supply output interface 16.
The transmitting link 1 (see fig. 2) receives a baseband signal generated by the digital DA, filters out-of-band noise through the first baseband low-pass filter 201 and the second baseband low-pass filter 202, enters the first video amplifier 203 and the second video amplifier 204 for signal amplification, the amplified signal is modulated to radio frequency through the IQ modulator 205, the out-of-band noise of the radio frequency signal is filtered out by the first band-pass filter 206, then is subjected to power amplification through the first radio frequency amplifier 207, and finally is output to the antenna front-end power amplifier module through the second band-pass filter 208. The transmitted signal requires high out-of-band rejection, high image rejection and good flatness.
The deskew link 2 (see fig. 3) receives a deskew reference signal coupled by the transmitting link, the deskew reference signal passes through the third band-pass filter 301 to filter out-of-band clutter, the deskew reference signal passes through the first mixer 302 to be mixed with the intermediate frequency local array signal, the mixing output signal passes through the fourth band-pass filter 303 again to filter out-of-band clutter, the mixing output signal passes through the third radio-frequency amplifier 304 to be amplified in power, the amplified signal meets the power requirement of the deskew local array, and the amplified signal is output to the receiving link to be deskew mixed.
In the design of a reference source link (see fig. 4), a direct frequency doubling mode is adopted, an output signal of a 100M constant temperature crystal oscillator 401 is amplified by a first amplifier 402, the amplified output signal drives a first SRD frequency multiplier 413 to generate a multiple frequency doubling signal, and a generated comb spectrum signal is divided into two paths by a first power divider 406: one path is gated by a second acoustic surface filter 412 to obtain a path of point frequency signals, and the point frequency signals are amplified by a third amplifier 411 and then output to a digital board as AD acquisition clock signals; the other path of comb spectrum signal passes through the first sound meter filter 407 to obtain another dot frequency signal, and the dot frequency signal is power-divided into three paths of dot frequency signals by the second power divider 409. One of the dot frequency signals is power-divided into two paths by the third power divider 415 again, and the two paths are respectively used as a DA clock signal and a demodulation local array signal of the receiving link; one path of the down-conversion mixing local array signal passes through the fourth amplifier 410 to be subjected to power amplification again and output as a deskew reference signal; the other path is amplified by a fifth amplifier 414, and then is subjected to a second SRD frequency multiplier 403 to generate a higher-order frequency-multiplied signal, and the signal is subjected to a microstrip filter 404 and a second radio frequency amplifier 405 to finally obtain a transmission modulation local array signal.
A receiving link (see fig. 5) receives echo signals amplified by low-noise amplification, the signals are filtered by an eighth band-pass filter 510, the filtered signals are mixed with deskew local array signals by a second mixer 509 to obtain deskew intermediate-frequency signals, the intermediate-frequency signals are filtered by a seventh band-pass filter 508 to remove unnecessary signal components, then the signals are sent to a sixth amplifier 507 for intermediate-frequency signal power amplification, the amplified signals are sent to an MGC gain controller 506 for gain control, the intermediate-frequency signals are adjusted to a proper level range by the gain control and then sent to an IQ demodulator 505 for baseband demodulation, in order to suppress near-end leakage signals, the demodulated signals are firstly filtered by a sixth band-pass filter 504 and a fifth band-pass filter 502 to remove high-frequency clutter signals and leakage signals of zero-frequency accessories, and finally the signals are amplified again by a fourth video amplifier 503 and a third video amplifier 501, and outputting the obtained video to the AD for digital acquisition.
The power supply in the power supply monitoring link (see fig. 6) is provided by a 28V DC power supply, and is converted by a DC-DC power supply module 601 and a DC-DC secondary power supply conversion module 602 to generate suitable voltages, such as positive and negative voltages, for each link. The power supply and main signal points are provided with level monitoring circuits, and the monitoring module 603 realizes level monitoring and MGC gain control so as to ensure that the equipment can be rapidly checked and positioned when the equipment fails. The power supply adopts a PCB bottom plate power supply mode, the PCB power supply plate is positioned in the back cavity of the cavity, and the feedthrough capacitor is adopted for supplying power for the radio frequency of the front cavity.
In the aspect of structural design, the utility model discloses with discrete subassembly such as transmission link, receiving link, declivity link and reference source link integrated to same structure, adopt the design in minute chamber in the structure to increase the isolation between the link unit, inside interconnection adopts the impedance microstrip line to carry out the interconnection. The integration level of the system is improved on the basis of finishing the established functional performance, the space is saved to the maximum extent, and the weight is effectively reduced. The external box body is formed by processing and assembling aluminum alloy plates, the cavity is designed in the box body, the groove type design is adopted on the wall of the box body, the box body has enough strength and rigidity and light weight, and the box body effectively reduces weight and has good heat dissipation performance.