Novel Single-Ended-to-Balanced Filter With Reconfigurable Working Modes, Frequency, Bandwidth, and Single/Dual-Band Operations

A novel single-ended-to-balanced (SETB) filtering circuit is proposed in this paper. The not only integrate controllable working modes between SETB and power dividing (FPD) into one unit, but also has multi-level reconfigurable capabilities including tunable center frequencies, bandwidths, switchable single/dual-band operations. It constructed by a 5-port symmetrical microstrip network. By properly engineering the transmission response of even odd mode circuit, multiple functions can be realized just mathematically sound way. FPD are switched leaving corresponding ports open, while control frequency, bandwidth, operation tuning capacitance value loaded varactors. Detailed theoretical experiment results have been given with good agreement.