Microstrip Cross-coupled Trisection Bandpass Filters Fabricated on High Dielectric Constant Ceramic Substrates

Miniaturized bandpass filters with sharp selectivity and low loss are required for wireless communication systems such as wireless local-area networks (WLAN). Since high permittivity dielectrics can reduce the size of bandpass filters, high dielectric constant ceramic materials are good candidates to prepare compact bandpass filters. In this work, a microstrip cross-coupled trisection bandpass filter was designed on high dielectric constant (Zn,Mg)TiO₃ dielectrics, The center frequency of simulated results is 2.41 GHz and the bandwidth is 120 MHz, while that of the measured center frequency is 2.38 GHz and the bandwidth is 160 MHz. The simulated and measured insertion loss of the filters are -1.737 dB and -2.759 dB, respectively. The measured response of the fabricated filter is in agreement with the simulated results.