A Technique for Tunable Filters with Low Insertion Loss and Narrow Bandwidth

Abstract

Abstract:A technique for tunable filters with low insertion loss and narrow bandwidth is proposed in the form of comb-line structure. Both resonant capacitor with pin-diodes and resonant inductance in the tunable filter were analyzed and the main source of insertion loss was obtained. A series of filters with same pin-diodes, center frequency, absolute bandwidth and low return loss was simulated. The results showed that, by changing the values of the resonant capacitor and inductance, insertion loss of the filter can be greatly restricted. This technique will allow the design of tunable LC filters with low insertion loss and narrow bandwidth.

A tunable filter with long hole resonance structure

“…The tunable filters have high vaule in applications because of greatly reducing the volume, weight and cost of the filter [8][9][10][11][12][13][14][15]. However, in some application environments, the weight of the active filter could still exceed the use requirements and more ideas and technologies are needed to further reduce the weight of the filter [16][17][18][19]. Based on the electromagnetic long wave scattering theory, this paper presents an tunable filter based on the long hole resonance structure.…”