Multilayer hairpin bandpass filter for digital broadcasting / Robi'atun Adayiah Awang … [et al.]

A design of multilayer hairpin bandpass filter at digital broadcasting frequency has been presented. This filter has been presented based on the design specification together with the analyses of the response on the parameter sweeps of coupling gap, width and length of the resonators, metal thickness, substrate thickness and the measurement result of the fabricated circuit. This research has proposed 2.45-2.53 GHz bandpass filter using hairpin resonator in multilayer configuration for digital broadcasting application. The four-pole hairpin resonators centered at 2.5 GHz with bandwidth less than 100 MHz were designed. The best return and insertion losses in the passband are -42.96 dB and -2.55 dB, respectively. Combination of hairpin resonator operating at desired frequency has been optimized and simulated on Flame Retardant 4 (FR-4) with dielectric constant 4.6 together with the analysis using Computer Simulation Technology (CST). Design filter has been fabricated and measured using Network Analyzer and have a good agreement with simulated response. The measurement results of Sn and S21 obtained from the fabricated circuit are -19.56 dB and -7.64 dB, respectively. The analyses have proven that the design work according to the microwave theory. In addition it was observed that a wider bandwidth was achieved by increasing the number of resonators.