| Title | Design of Contiguous-Band Elliptic-Response Manifold Output Multiplexers by Efficient Cancellation of Reactive Impedance Parts |
| Publication Type | Conference Paper |
| Year of Publication | 2011 |
| Authors | Montejo-Garai, J. R., C. A. Leal-Sevillano, J. A. Ruiz-Cruz, J. M. Rebollar, L. Rogla, and S. Sobrino |
| Conference Name | Proc. VIII Encuentro Ibérico de Electromagnetismo Computacional (in Spanish) |
| Date Published | Nov. |
| Abstract | In recent years, there has been an increasing demand for satellite communication channels with a complex response, motivated by a most effective use of the radiofrequency spectrum. This means that more channels have to be combined in the output multiplexer (OMUX) after power amplification. In this paper, a synthesis technique based on the Cauer ladder development has been developed to design the singly terminated filters for manifold multiplexers. A procedure for the synthesis and design of contiguous band manifold output multiplexers based on singly terminated filters with elliptic response is considered. The zero shifting technique leads to the synthesis of a driving–point impedance including transmission zeros at finite real frequencies. The synthesized canonical forms have different topologies, number of reactive constant elements and reactive part of the driving impedances with different frequency responses. These characteristics have been intensively analyzed to find the most suitable combination in the multiplexing process to match the channels to the manifold. Using the methodology presented in this work a four-channel multiplexer for Ku-band operation has been designed, manufactured and measured. The input–output ports are standard WR75. The prototype has been manufactured in brass using low-cost milling technique and is formed in one block where all the cavities and irises have the same height. The unloaded Q for the brass cavities is 2500 and therefore the expected insertion losses at central frequency of the higher channel are approximately 2.5 dB. The final paper will show a comparison between the full-wave simulation using the mode-matching method (including losses) and the measurements of the input reflection coefficient and the transmission of the manufactured multiplexer. |
