在毫米波交会探测器设计中,谐波混频器的隔离度和变频损耗直接影响探测器的目标交会探测性能。依据谐波混频器原理,提出了在射频端用带阻滤波器代替带通滤波器提高端口隔离度的设计方案,采用增加反射回收枝节的方法优化了匹配电路,并利用ADS软件完成了带阻滤波器、低通滤波器以及匹配电路等各组成单元的电路仿真。实测结果显示:当输入的本振频率为17.35 GHz,功率为15 dBm时,在34 GHz~36 GHz的射频输入频段内变频损耗小于9 dB,射频本振的端口隔离度大于40 dB。

In the design of millimeter wave rendezvous detectors, the target rendezvous detection performance of the detector is directly affected by the isolation and conversion loss of the harmonic mixer. Based on the principle of the harmonic mixer, a design scheme of using a band-stop filter instead of a band-pass filter at the radio frequency (RF) end to improve port isolation is proposed, and the matching circuit is optimized by adding reflection recovery branches. The ADS simulation of each component unit such as band-stop filter, low-pass filter and matching circuit is completed. The actual measurement results show that when the input local oscillator frequency is 17. 35 GHz and the power is 15 dBm, the frequency conversion loss in the 34 GHz~36 GHz RF input frequency band is less than 7 dB, and the port isolation of the RF local oscillator is greater than 40 dB.

TN773