A radio frequency cancellation system and radio frequency cancellation method for continuous wave radar

Abstract

The invention discloses a radio frequency cancellation system and method for a continuous wave radar. The system comprises a signal acquisition module used for obtaining partial transmitting signal output from a transmission channel, a vector modulation module for inputting a path of partial transmitting signal, executing modulation and phase modulation with first phase shift and second quadrature modulation, and then outputting an initial cancellation signal with the opposite phase of a leakage signal which enters into a receiving channel, a gain adjusting module used for carrying out gain adjustment on the initial cancellation signal, outputting a target cancellation signal with the same amplitude of the leakage signal, a cancellation module used for connecting the target cancellation signal into the receiving channel and allowing the target cancellation signal and the leakage signal to be stacked to obtain a cancelled receiving signal. The system and the method have the advantages of a simple realization structure, the realization of full phase range RF signal cancellation, a good cancellation effect, low cost, and a wide range of application.

Description

technical field [0001] The invention relates to the technical field of frequency modulation continuous wave radar, in particular to a radio frequency cancellation system and a radio frequency cancellation method for continuous wave radar. Background technique [0002] The two most widely used radar systems today are frequency-modulated continuous wave radar and pulse radar. Among them, frequency-modulated continuous wave radar has the characteristics of high integration, small size, and high resolution at close range. It is especially suitable for various types of different functions in the automotive and other fields. Radar requirements, the vast majority of automotive radar is the use of frequency modulation continuous wave system. However, since the FM CW radar works continuously, it cannot avoid the leakage signal by time-sharing gating like the pulse radar. Therefore, if no effective processing is performed, the leakage signal entering the receiver channel in the FM CW ...

AI Technical Summary

Problems solved by technology

For the radio frequency cancellation technology, the following schemes are mainly adopted at present: the first one is to use transistors as controlled resistors for design, which requires more passive structures in the circuit, and is limited by the performance of the substrate material. The larger the size of the structure at low frequencies, the larger the area required for the overall system, which cannot meet the needs of miniaturization; if the design is based on the MMIC chip process based on transistors, although the problem of excessive system size can be solved, the initial design of the chip and tape-out processing The cost required is very high; the second is to use radio frequency chips for design and implementation, the design structure is usually relatively simple, and is limited by the performance of the phase shifter chip, it is impossible to achieve 360-degree modulation of the phase, and the control of the phase shifter The number of digits is not high, so the modulation accuracy of the chip is not high, and the minimum phase shift that can be achieved at present is also greater than 1 degree, so the corresponding cancellation effect is not complete; the other is to use multiple phase shifter chips to achieve , although the performance can be improved, but because the phase shifter chips suitable for high frequency applications are usually expensive, if multiple phase shifters are used at the same time, the cost of the entire system will be greatly increased

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