Calibration method for microwave vector modulation in doppler signal simulation

Abstract

The invention relates to a calibration method for microwave vector modulation in doppler signal simulation. The calibration method comprises the following steps: (1) design of a compensating circuit: adding one compensating circuit in front of the Q input end of a vector modulator, wherein the transmission function of the compensating circuit is e-j delta / k, that is the compensating circuit is one circuit with the gain being 1 / k and the phase-shift angle being -delta; (2) calculation of a gain error k and a phase-shift error delta: designing a vector modulation calibration circuit, then calculating with two steps to obtain calibration data of vector modulation amplitude unbalance in the first step and to obtain calibration data of vector modulation phase-shift errors in the second step; (3) compensation of the gain error k and the phase-shift error delta. According to the calibration method, after the calibration method compensates a broadband microwave vector modulator, the carrier rejection and image rejection indexes of output signals of the vector modulator are improved by 20 dB, the typical value is superior to 40 dB, and the technical characteristic of the system is greatly improved.

Description

technical field [0001] The invention relates to the field of microwave signal generation, in particular to a calibration method for microwave vector modulation in Doppler signal simulation. Background technique [0002] In the fields of deep space exploration and satellite communication, the instantaneous speed of the detector and satellite relative to the earth is very high, and the Doppler frequency shift of the communication signal will be very high at this time. If the design of the communication system is not perfect, the detector and satellite will be lost. control, leading to the failure of the launch mission and wasting a lot of manpower and material resources. Therefore, when designing these communication systems, it is necessary to simulate the Doppler effect of communication signals in the laboratory, evaluate the reliability of communication devices, and improve the design of the system. [0003] Radar is an important category of military and civilian electronic...

AI Technical Summary

Problems solved by technology

[0017] Due to the design technology and process limitations of the broadband microwave vector modulator, its carrier suppression, sideband suppression and other indicators are not ideal

In the microwave frequency band, it is quite difficult to directly compensate the amplitude imbalance of the vector modulator, especially the phase shift error

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