Switchable Absorptive Bandstop to Bandpass Filter using Stepped-Impedance Dual Mode Resonator

In this paper, a new switchable absorptive bandstop to bandpass filter using stepped-impedance dual mode resonator is proposed. This switchable filter provides two modes of operation which is absorptive bandstop and bandpass response. The first part of this paper presents a theoretical analysis of the absorptive bandstop filter using steppedimpedance dual mode resonator. The absorptive bandstop response can be achieved by connecting λ/4 length with the stepped-impedance dual mode resonator with correct diameter and position of via hole as an inductive element. The second part of this paper presents an investigation and design of the switchable absorptive bandstop to bandpass filter. PIN diodes are used as the switching element. The selectivity of the bandpass response can be improved by using extended via hole. The parametric studies together with the EM simulation of the new switchable absorptive bandstop to the dual mode bandpass filter is presented in this paper

An Investigation of Switchable Matched Bandstop to Bandpass Filter Based on Lossy Resonator

Filters are the basic component of transceivers and receivers in the RF front-end communication system, either as band reject or band select units. This research is about an investigation of the new switchable filter which is can switch from matched bandstop to bandpass filter based on lossy resonator, where the lossy resonator topology can be used to partially compensate for the loss. The aim of this research work is to investigate the switchable matched bandstop to the bandpass filter response using lossy resonator based on EM modeling. This filter will be realized in parallel-coupled L-shape resonator. A PIN and varactor diodes will be used to make the filter switchable. This switchable filter provides two modes of operation; matched bandstop and bandpass response. The operating frequency is 2.4 GHz. The theoretical analysis together with EM modeling of the new switchable matched bandstop to bandpass response are presented in this paper