Design of Dual-Channel Filter Based on Dual-Mode Dielectric Resonators

Abstract

In this brief, the design approach of dual-channel filter based on dual-mode dielectric resonator (DR) is proposed. A pair of orthogonal modes in dual-mode DR with the same and different frequencies are analyzed and applied to construct the two channel filtering responses independently. Meanwhile, the isolation between the two channels can be realized due to the orthogonality between the modes. Thus, the design process is simple and efficient. To verify the design approach, two prototypes with the same and different frequencies are designed. Meanwhile, the <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$3^{rd}$ </tex-math></inline-formula> -order dual-channel filter with different frequencies are also implemented and measured. The frequencies of the two designs are 1.54GHz and 1.53/1.68GHz, respectively. In each design, the return losses of the two channels are better than 14dB, the insertion losses are less than 0.68dB, and the band isolation is greater than 20dB. Meanwhile, the results also show that arbitrary filtering order and high design flexibility can be achieved.