A Design of Miniaturized C Band Filter Based on Tai-chi Resonators

In this paper, a compact C band filter is presented, which is based on Tai-chi diagram resonators. In order to reduce the size of the band pass filter (BPF), the quarter-wave length of Tai-chi diagram structure have been adopted to design a new type of stepped impedance resonator (SIR), and the size of the BPF is less than 15.5mm*15.5mm*0.508mm. The band of the BPF operates form 5.5GHz to 6.1GHz with an insertion loss less than 1.6dB, and the minimum insertion is less than 0.67dB with the return loss less than -17dB in passband. The measurements are in good agreement with the simulation results.