Configurable digital correlator for complete polarization microwave radiometer system

Abstract

The invention relates to a configurable digital correlator for a complete polarization microwave radiometer system. At a radio frequency front end of the complete polarization microwave radiometer system, a signal after frequency-mixing amplification and orthogonal transformation is transformed to be a differential signal and then is input into four ultrahigh-speed ADC (Analog to Digital Converter) input ends to be converted into a digital signal after sampling conversion, and the digital signal after multi-path multiplexing is input into a digital correlative circuit; the digital correlativecircuit comprises a parameter selection module and a correlative calculation module, wherein the parameter selection module returns a command to modify a digital correlative digit parameter and an integration time parameter in an FPGA (Field Programmable Gate Array) through a serial port of a computer to configure the FPGA in real time so as to realize digital correlation from 2 bits to 12 bits and selection of the integration time from 5ms to 50ms; and the correlative calculation module executes deceleration and correlative calculation processing on the input digital signal after determiningquantization digit and the integration time and outputs a correlation result to a computer through a data format conversion and external interface circuit according to a required sequence.

Description

technical field [0001] The invention relates to a digital correlator, in particular to a configurable digital correlator used in a full-polarization microwave radiometer system. Background technique [0002] The digital correlator refers to the use of digital methods to perform correlation processing on the input signal. Digital correlation technology is widely used in communication and microwave remote sensing systems, especially in fully polarized microwave radiometer systems and synthetic aperture radiometer systems. In the synthetic aperture radiometer system, digital correlation is mainly used to realize the cross-correlation of multiple channels. A single correlator can complete the cross-correlation calculation of multi-channel signals, saving a lot of volume, weight and power consumption. In the full-polarization microwave radiometer system, the digital correlator is mainly used to realize the broadband complex correlation after the dual-polarization channel is mixe...

AI Technical Summary

Problems solved by technology

At present, there are many digital correlators implemented by integrated circuits, but they have not reached the level of 12-bit quantization under 3.2GHz bandwidth, and the correlation calculation accuracy and integration time cannot be adjusted at any time, which limits the scope of use of digital correlators.

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