一种宽带数控模拟复相关器的设计及实现

Design and implementation of a digitally controlled wideband analog complex correlator

介绍了一种加法型增益与偏置可数字控制的1.5~2.5GHz模拟复相关器的设计原理及实现过程,并分别在点频与宽带输入信号情况下,评估了复相关器的等效相关带宽与相位的测量精度,以及在不同输入功率情况下的信噪比。实验结果表明,此模拟复相关器的增益与偏置可实现数字自动调整,在1GHz工作带宽内幅度变化不超过1.5dB,等效相关噪声带宽达到0.905GHz,相位测量精度优于2.5°,在输入功率为-13dBm时,信噪比达到13dB。

A 1.5 GHz-2.5 GHz analog complex correlator using ＂add and square＂ scheme was designed and implemented for passive millimeter-wave imaging applications. A digital gain and offset control scheme was adopted. The results of single frequency test show that the output amplitude variation is less than 1.5 dB, and the equivalent correlation bandwidth is 0.905 GHz. Meanwhile, the results of broadband noise measurement show that the correlator phase accuracy is better than 2.5°. At last, an experiment under low SNR environment is carried out to evaluate the influence on the signal-to-noise ratio （SNR） brought by different input power. The results show that in the range of -20- -10 dBm, SNR becomes higher as input power increases and SNR is 13 dB when input power reaches -13 dBm.