Novel Reconfigurable Diplexers Based on Short-Circuited Stub-Loaded Resonator

In this paper, novel reconfigurable diplexers based on short-circuited stub-loaded resonators are presented. Firstly, a reconfigurable wideband to dual-band filtering diplexer based on reconfigurable multi-mode resonator is proposed. Each channel of the diplexer has two operation modes, i.e., wideband bandpass filter (WB-BPF) and dual-band bandpass filter (DB-BPF), which can be switched by changing on state or off state of p-i-n diodes, and four independently switchable operating states are presented. Secondly, a tunable diplexer based on short-circuited stub-loaded resonator has been presented. Varactor diodes are loaded at the end of the resonator to control the central frequencies of tunable diplexer. Mixed electromagnetic coupling is formed by vias and the gaps between the resonators, transmission zeros are produced and the isolation of the diplexer is improved.