A microstrip triangular spiral resonator for bandpass filter design

This paper presents the design of a microstrip Chebyshev filter based on a triangular spiral resonator. Its performance is here reported and compared with the performance of a filter designed based on a simple microstrip triangular open loop resonator. The objective of the paper is to show that a triangular spiral resonator filter with the area equal to the area reduced of 48 % of a filter based on the triangular open loop resonator can perform very similarly in the band of interest and with the same Chebyshev characteristics. Experimental results are reported and confirm the prediction.