Amplitude phase characteristic test method for down-conversion reception channel of ultra-wide band synthetic aperture radar (SAR) receiver

Abstract

The invention discloses an amplitude phase characteristic test method for a down-conversion reception channel of an ultra-wide band synthetic aperture radar (SAR) receiver and relates to an SAR system testing technology. The amplitude phase characteristic test method comprises a first step of establishing a parametric mixer and connecting a vector network analyzer; a second step of performing standard single-port correction on two ports of the vector network analyzer respectively within an input frequency range and an output frequency range of the tested down-conversion reception channel; a third step of establishing a calibration mixer and performing representation of the calibration mixer; a fourth step of utilizing the calibration mixer to perform straight-through calibration; and a fifth step of testing amplitude phase characteristics of the down-conversion reception channel. The method is mainly used for measuring amplitude phase frequency characteristics of the down-conversion reception channel of the synthetic aperture radar multichannel receiver and has the advantages of being high in measuring precision and simple, convenient and fast to achieve, and necessary means are provided for accurate extraction and compensation of SAR system amplitude phase errors.

Description

technical field [0001] The invention relates to the technical field of synthetic aperture radar (SAR) system testing, in particular to a method for testing amplitude and phase characteristics of a down-conversion receiving channel of an ultra-wideband SAR receiver. Background technique [0002] Synthetic Aperture Radar (SAR) is a microwave remote sensing method for imaging and observing ground targets. It has the advantage of being able to work around the clock, so it is widely used in national defense, natural resource exploration, disaster monitoring and other fields. With the continuous development of SAR imaging technology, the resolution of SAR imaging is also increasing. Ultra-wideband SAR can achieve a resolution better than 0.1m, and can achieve very fine imaging on the ground, which is of great significance in both military and civilian applications. [0003] However, ultra-wideband SAR needs to transmit and receive chirp signals with a very wide absolute bandwidt...

AI Technical Summary

Problems solved by technology

The advantage of this technology is that the vector network analyzer used does not need to have a frequency offset function. The disadvantage is that the operation and calculation are cumbersome, requiring manual or programming calculations. In addition, the more important thing is that its test accuracy is limited by the standing wave at the mixer port. In the stage of two-by-two characterization of three mixers, the matching characteristics between the mixers will bring systematic errors, which are determined by this test framework and cannot be corrected by instruments. In the DUT test stage, it is transferred to the test results, which affects the test accuracy. In addition, in the DUT test stage, the matching characteristics between the DUT and the mixer with known frequency response will also have a certain impact on the test accuracy. Influence, especially for the accuracy of the measurement of phase characteristics is more serious

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