Transceiver system implementation method for implementing digital phase shift and calibration with DDS (Direct Digital Synthesizer) as local oscillator

Abstract

The invention belongs to the field of radar microwave transceiving, and especially relates to a transceiver system implementation method for implementing digital phase shift and calibration with a DDS(Direct Digital Synthesizer) as a local oscillator. The DDS generates four paths of outputs to each path of T / R channel used as a third local oscillator; a waveform generation plug-in of a radar frequency source extension generates an intermediate frequency waveform and then the intermediate frequency waveform is provided to eight four-channel T / R components through an eight-way power divider; afirst local oscillator and a second local oscillator generated by the radar frequency source extension are sent to eight four-channel T / R components through the eight-way power divider; a single DDS processing module can carry out phase shift on four transmitting channels at the same time; and when a radar works in a transmission calibration mode, a calibration plug-in receives and processes signals sent by a calibration network and converts the signals into optical fiber signals to be output. The transceiver system implementation method for implementing the digital phase shift and calibrationwith the DDS as the local oscillator provided by the invention fully utilizes the advantages that DDS phase shift is simple and feasible, large in number of bits, high in precision, lower in price, small in size, multiple in channels and the like, and overcomes the problems that a traditional digital phase shifter is high in price, limited in the number of bits, low in integration level, large inweight and each channel needs a phase shifter.

Description

technical field [0001] The invention belongs to the field of radar microwave transceiver, in particular to a radar transceiver system implementation method in which DDS is used as a local oscillator to realize digital phase shift and calibration. Background technique [0002] With the application of phased array radar, the integration level of the transceiver system and the phase consistency requirements between channels are getting higher and higher. As a key component of phased array radar, the phase control and calibration of T / R components has become particularly important. Its control digits and precision are the key technologies to measure the performance of phase shifting. The phase control of the receiving system is mostly implemented by DBF (Digital BeamForming) technology without adding hardware circuits to the system. The phase control of the transmitting system is often implemented by digital phase shifters or by DDS (Direct Digital Synthesizer) to generate trans...

AI Technical Summary

Problems solved by technology

[0003] Traditional digital phase shifters are mostly realized by PIN tubes, with limited number of bits and high price. At present, 6-bit or 8-bit phase shifters are commonly used, and at least one phase shifter is required for each transmission channel. Generally speaking, the quality is heavy ,Big size

[0004] Although the method of generating the transmitted waveform and shifting the phase through DDS can solve the problem of the limited number of phase shifts of the traditional digital phase shifter, the output signal has limitations in performance and mode.

Generally speaking, radars require many types of transmit waveforms and complex modulation methods, and have high requirements for the signal quality of transmit waveforms. It is relatively simple for DDS to output linear frequency modulation signals, but for non-linear frequency modulation and phase-coded signals, It is more complicated to implement, and the phase noise and spurious suppression indicators of the DDS output signal are relatively low. In order to meet the signal quality, it is often necessary to improve the requirements for the DDS chip. In order to realize the generation of complex waveforms, it is necessary to improve the control chip FPGA (Field Programmable GateArray) performance requirements directly lead to an increase in design cost

[0005] Moreover, there is no system and method for health diagnosis and online monitoring of the transceiver system in the existing radar system

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