Design and Implementation of a DC- 18 GHz Microwave Triplexer in Suspended Stripline Technology

Document Type : Original Article


1 Department of Communication, School of Electrical and Computer Engineering, University of Tehran, Tehran,Iran

2 ECE Dept. University of Tehran

3 Department of Communication, School of Electrical and Computer Engineering, Shiraz University, Shiraz, Iran


This paper presents design, optimization and measurement results of a microwave triplexer implemented using suspended stripline technology to separate DC-18 GHz input signal into three jointed frequency ranges of DC-2 GHz, 2-6 GHz and 6-18 GHz with VSWR better than 2, isolation higher than 50 dB and insertion loss better than 1 dB. The proposed triplexer consists of lowpass and pseudo-highpass filter channels connected by suitable high and low impedance T-junctions. These filters are realized using generalized Chebyshev lowpass prototype to achieve high selectivity and sharp band-edge roll-off with ease in implementation by using printed circuit board technology. Stepped impedance resonators are used to achieve a better impedance matching and wideband response. The triplexer pattern is implemented on a 0.254 mm-thick RT/duroid 5880 substrate with dielectric constant of 2.2, suspended symmetrically between two ground planes which enables the realization of a contiguous triplexer with low insertion loss, high selectivity and high isolation. This Triplexer can be used in Radar warning receivers and electronic intelligent systems.


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