Multilayer structure of ring resonator filter for digital broadcasting

This paper presents a design of a multilayer bandpass filter. The filter is constructed from a combination of end-coupled and ring resonators for digital broadcasting applications. The filter is designed to work at 2.6 GHz with a bandwidth of 4%. A 0.75-mm-thick of Roger RO3003 substrate with dielectric constant, ε_r of 3.0 is used as a core material of the circuit. The bandpass filter was simulated using Computer Simulation Technology (CST) simulator. Results from the electromagnetic simulation are presented together with some investigations have been done to obtain the best response. From the observation into the filter responses, the results agree well to the microwave theory.