A high stability fully tunable filter with frequency, bandwidth and transmission zero tuning

Abstract

Based on the double folded 1/4 mode substrate integrated waveguide (DFQMSIW) resonator, a two-pole DFQMSIW tunable filter with frequency, bandwidth and transmission zeros tuning is proposed in this paper. In order to increase the stability of the filter, the constant bandwidth can be maintained by changing the coupling coefficient by two varactor diodes when tuning frequency and transmission zeros. The center frequency can be tuned in the range of 1.1 GHz-1.9 GHz, transmission zeros can be tuned from 1.41 GHz to 1.5 GHz with bandwidth unchanged, and bandwidth can be tuned from 120 MHz to 200 MHz. The insertion loss is about −1.3 dB to −3 dB.

Switched integrated band-pass filter bank utilizing 0.25-um pHMET GaAs process for S-, C-, and X-band applications

“…As an essential component of multi-band wireless communication systems, frequency reconfigurable bandpass filters (BPFs) need low insertion loss, outstanding frequency selective characteristics, small area, and feasibility [2]. Many research efforts in the past decade have been done to meet the above needs [1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29]. The design techniques for these frequency reconfigurable BPFs include the utilization of tunable BPFs [3,4,5,6,7,9,11,12,13,17,18,19,20].…”

“…Many research efforts in the past decade have been done to meet the above needs [1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29]. The design techniques for these frequency reconfigurable BPFs include the utilization of tunable BPFs [3,4,5,6,7,9,11,12,13,17,18,19,20]. They have minimal components and continuously tuned ability but suffer from high nonlinearity due to nonlinear components usage, including varactor diode.…”

A High-Temperature Superconducting Bandpass Dual-Mode Filter with Tunable Relative Bandwidth and Center Frequency

“…Recently, extensive studies on filters have been conducted, resulting in the rapid development of modern WCSs, which generally run at multiple standards and frequencies. Particularly, filters with electronic tunability and reconfigurability are crucial in modern WCSs because they can reduce cost and system complexity [ 4 , 5 , 6 , 7 ]. Filters with microwave tenability are crucial for WCSs both presently and in the future.…”