Dual-band Band-pass Tunable Filter with Meander-Line Resonator

Abstract

Radio frequency (RF) that can be tunable filters are band-pass filters (BPFs) with finely tunable passband frequencies. The passband frequency can be changed digitally, mechanically, or with a control voltage. Tunable BPF designs are increasing in importance as communication systems become more complex. In this study, a dual-band band-pass tunable filter with a meander-line resonator has been proposed. It aimed to create a tunable band-pass filter design in two different bands by using the SVM1413 varactor diode and gradually changing the capacitance value. SVM1413 varactor diode has been chosen in terms of applicability and capacitance value range width. The BPF operates in two different frequency ranges, from 2.5 to 3 GHz and from 4.2 to 4.6 GHz. BPF has been implemented and measured on a Rogers RO3003 substrate with a dielectric constant of 3 and a thickness of 1 mm. The substrate for the BPF has been chosen to be 30 × 30 mm^2 in size. The numerical calculation results have been simulated and optimized using computer simulation technology (CST). The insertion loss values are above -1 dB in both bandwidth ranges and all capacitance changes. Better results have been obtained when numerical calculation results have been compared with the outputs of the sources used.