A tri-band bandpass filter with asymmetric tri-mode resonator

In this paper we propose a compact tri-mode asymmetric resonator that consists of a single-mode and a dual-mode resonator. The behaviour of the proposed configuration is analyzed in detail. To demonstrate the potential of the proposed resonator, tri-band bandpass filter operating at 2.4/3.5/5.2 GHz has been designed, fabricated and measured. The filter is characterized by good performances and very compact size of only 0.24λ
_g
× 0.115λ
_g
.