Frequency modulation continuous wave (FMCW) radar zero intermediate frequency image rejection receiver

Abstract

The invention discloses a frequency modulation continuous wave (FMCW) radar zero intermediate frequency image rejection receiver. A circuit thereof comprises a low-noise amplifier, an I-path mixer, a Q-path mixer, a frequency sensitivity controller, a first low-frequency amplifier, a low-pass filter, a second low-frequency amplifier, a 90-degree power division phase shifter and a 90-degree phase shift synthesizer, wherein the low-noise amplifier is respectively connected with the I-path mixer and the Q-path mixer; the 90-degree power division phase shifter is connected between the I-path mixer and the Q-path mixer; the I-path mixer and the Q-path mixer are respectively connected with the 90-degree phase shift synthesizer; and the frequency sensitivity controller, the first low-frequency amplifier, the low-pass filter and the second low-frequency amplifier are successively connected behind the 90-degree phase shift synthesizer. The receiver has the advantages of simple circuit and low cost, simultaneously inhibits the image noise of the zero intermediate frequency receiver and improves the sensitivity.

Description

technical field [0001] The invention relates to a radar receiver, in particular to a frequency-modulated continuous-wave radar zero-center image suppression frequency receiver. Background technique [0002] The zero-IF receiver directly demodulates the baseband signal without passing through the IF, which is beneficial to the miniaturization and low cost of the system. On the other hand, the number of circuit modules and external nodes required by the system is reduced, which reduces the power consumption required by the receiver and reduces the chance of external interference of radio frequency signals. Zero-IF receivers are widely used. [0003] There are two methods for the existing FM CW radar zero-IF receiver, one is the direct frequency mixing method, and its circuit principle can be found in figure 1 , including a low-noise amplifier, a mixer, a frequency sensitivity controller, a first low-frequency amplifier 1, a low-pass filter and a low-frequency amplifier 2, th...

AI Technical Summary

Problems solved by technology

[0006] In order to solve the problem of image frequency suppression in FM CW radar zero-IF receiver, the object of the present invention is to provide a FM CW radar zero-IF image suppression receiver

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