A Compact Tunable Dual-Band Bandpass Filter Based on Substrate Integrated Waveguide and Defected Ground Structure

Abstract

Abstract-A compact tunable dual-band bandpass filter (BPF) based on substrate integrated waveguide (SIW) and defected ground structure (DGS) is investigated in this paper. The second passband can be flexibly controlled by changing the dimensions of the updown DGSs whereas the first passband is fixed. The proposed filter exhibits improved selectivity due to the introduction of four left-right DGSs generating transmission zeroes. To verify the design method, a compact dual-band filter with the second center frequency switched among 5.4 GHz, 5.8 GHz, 6.4 GHz and 6.8 GHz and the first center frequency fixed at 4.78 GHz, is designed and fabricated. The simulated and measured results are in good agreement with each other.

Modelling and analysis of Substrate Integrated Waveguide (SIW) and half-mode SIW (HMSIW) band-pass filter using reactive longitudinal periodic structures

“…Methods to reduce spurs in Microwave X-band BPF which are required for good filter design discussed in [12]. Compact tunable dual-band SIW BPF using DGS has been reported in [13]. The technique is found to provide flexibility in choosing second passband mostly in lower microwave bands by changing dimensions of DGS.…”

Two Kinds of Dual-Band Bandpass Filter Based on a Single Square Ring Resonator

“…The stepped impedance resonators (SIRs) and stub loaded resonators (SLRs) are also employed for dual-band operation [4][5][6], and at least two resonators are required. Other methods such as, defected ground structure (DGS) [7,8], shorted-ended dual-mode resonator (SEDMR) [9], coupled line resonator [10], and low temperature cofired ceramic (LTCC) [11] have also been proposed for dual-band applications.…”