Temperature-compensated open-loop tuning of a dual-notch absorptive bandstop filter

Abstract

For the first time, a scalable open-loop temperature-compensated tuning approach is presented for dual-notch absorptive bandstop filters (ABSF). A post-fabrication calibration procedure is detailed to generate a surrogate model that can be utilized for highly accurate in-the-field tuning of parameter-sensitive ABSFs. Notch frequency variations of less than 0.06% and isolation improvements of over 30 dB are measured for a dual-notch ABSF across its quasi-absorptive tuning range from −25 to 85° C.