Wide-stopband, compact microstrip diplexer with common resonator using stepped-impedance resonators

Abstract

A novel microstrip triplexer with a common crossed resonator and some uniform impedance resonators (UIR) is proposed in this paper. The crossed resonator is theoretically analyzed and proved to be able to resonate at three different frequencies. By using the crossed resonator as the common resonator, a compact structure can be gained as no extra matching network is needed, and the number of the resonator can be reduced effectively. Moreover, a wide stopband is obtained by setting the crossed resonator and UIRs working at the same fundamental frequencies but different higher order resonant frequencies. To demonstrate the design procedure, a triplexer with a third order Chebyshev response in each channel is fabricated and measured. The measured result is in good agreement with the simulated one, showing an attenuation of 20 dB up to 8 times the first channel frequency.

Compact Microstrip Diplexer Based on Dual Closed Loop Stepped Impedance Resonator

“…However, such waveguide design is challenging to be integrated directly within a planar system. The most common methods to form a planar diplexer are based on designing two BPFs separately with different frequencies, then using T-junction [2,3], Y-junction [4,5], common resonator [6,7], and matching circuit [8,9] to combine these two BPFs to form the final diplexer circuit. However, most of these diplexers are not small enough to be used.…”

Wide Stopband Compact Microstrip Quadruplexer Using Common Crossed Resonator

“…By properly designing the length and width of the SIR, it can work at two or more different frequencies. In [10,11], a SIR was used as a common resonator to form a diplexer. Both the diplexers have a wide stopband because of the different high order resonance frequencies of those resonators involved [14].…”

Wide Stopband Microstrip Triplexer Using Common Crossed Resonator and Uniform Impedance Resonator

“…By using a multi-mode resonator as a common resonator shared by different channels, the matching network is not needed and the number of resonators can be reduced. Several works have been done on this issue [4][5][6][7]. But most of them were studying about diplexers and the work on triplexers is much less.…”

“…Among various resonators, the most popular common resonator is SIR. In [4,5], a SIR was used as a common resonator to form a diplexer. By properly design the length and the width of the SIR, it can resonate at two or more different frequencies.…”