Single-side-coupled ring resonator filter / Nadirah Aziz

In this paper, a Single-Side-Coupled Ring Resonator circuit is designed and fabricated. This filter has a ring structure and has one coupled-line at one side of the ring. The filter which is designed at a centre frequency of 2GHz has one pole and is considered as a 1st order filter. This filter is simulated by mean of CAD and to obtain the desired response, the length and the width of the filter element are tuned. After the desired response is obtained, the simulated filter is fabricated on Fire-Retardant 4 (FR-4) substrate. This FR 4 has a permittivity of 5.4 and a thickness of 1.6 mm. The dimension of the fabricated filter is 6.6 x 6.7 cm. The fabricated filter is then measured to verify the theory. The measured result shows that the filter return loss is -17.14 dB and the filter has a minimum insertion loss of-3.98 dB. This filter has been verified by simulation and measurement.