Dual-Band Bandpass Filter Based on Coupled Complementary Hairpin Resonators (C-CHR)

A novel dual-band bandpass filter (DB-BPF) with controllable parameters in design process and a compact structure is introduced in this paper. The total structure includes open-circuited and short circuited coupled-lines, leading to a compact circuit. The resonance frequencies, insertion loss and quality factor can be independently controlled by adjusting the coupled lines. In order to eliminate the magnetic and electric coupling effects, the virtual grounds are placed in coupled complementary hairpin resonator. To verify the validity of the design approach, a DB-BPF centring, at 3.5 and 5 GHz with respective insertion losses of 0.7 and 0.58dB for WIMAX (IEEE 802.16 band) and WLAN (IEEE 802.11 band) applications has been designed and fabricated, whose the measured results confirm the electromagnetic simulation