Double-fundamental-frequency three-channel time-base control circuit of through-wall imaging radar

Abstract

The invention relates to a double-fundamental-frequency three-channel time-base control circuit of a through-wall imaging radar. The double-fundamental-frequency three-channel time-base control circuit comprises an FPGA time sequence control circuit, a programmable time sequence control circuit, a system clock circuit, a reference clock circuit and three paths of delay pulse output circuits whichare arranged in parallel; the FPGA sequential control circuit is electrically connected with the system clock circuit and used for outputting initial pulses, delay data, fine adjustment data and channel gating signals; and the programmable time sequence control circuit comprises an ECL conditioning circuit, a programmable time delay chip and a fine tuning DAC chip. According to the invention, high-precision and large-range time delay control of three channels is realized through the sequential control circuit; two fundamental frequency clocks are synchronously designed, so that time jitter errors are reduced, and the stability of the pulse signal generation module is improved; and 16-bit delay configuration control word setting can be performed, parameter adjustment is flexible, ultrahighdelay precision of 2ps can be realized, continuous scanning of a maximum 2000ns time window can be realized, three paths of delay pulses can be simultaneously transmitted or transmitted in a time-sharing manner, and a time-sharing transmission time interval is controllable.

Description

technical field [0001] The invention relates to the technical field of radar, in particular to a dual-base frequency and three-channel time base control circuit for through-wall imaging radar. Background technique [0002] One of the technical difficulties in the development of real-time through-wall imaging radar system is how to obtain stable ultra-wideband radar signals. Through-The-Wall Radar Imaging, edited by Moeness G.Amin of the United States, discloses a real-time through-the-wall imaging radar system composed of a PCI-based computer system and a real-time sampling oscilloscope. In this system, in order to obtain ultra-wideband pulses with a width of 1 ns, the real-time sampling resolution is required to reach 200 ps (5G / s sampling rate), and the analog bandwidth of several gigahertz (GHz). Although this method is feasible, the cost is too high, and it is difficult to process the real-time digital data stream of 5×109 samples per second. [0003] Since the through...

AI Technical Summary

Problems solved by technology

The time base resolution used by traditional wall-penetrating radars is mostly 5ps to 20ps, and sampling is carried out by means of equal-interval cycle scanning. The accuracy of the sampling frequency has reached the bottleneck, and it is impossible to obtain more accurate detection data.

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