Waveguide diplexer designs are widely used for telecommunications, space, and terrestrial applications. Although mathematical models and design procedures for waveguide filters are known, diplexer designs still remain complex and time consuming. This paper describes how to obtain an equivalent circuit network model and a complete design of non-contiguous diplexers using a computer-aided approach with a classic Y-junction. Results are satisfactory in terms of reduced design time and performance. Examples including physical dimensions are provided.
2. Levy, R., "Theory of direct coupled cavity filters," IEEE Trans. on Microwave Theory and Techniques, Vol. 11, 340-348, Jun. 1967.
3. Rhodes, J. D. and R. Levy, "A generalized multiplexer theory," IEEE Trans. on Microwave Theory and Techniques, Vol. 27, 99-111, Feb. 1979.
4. Vanin, F. M., D. Schmitt, and R. Levy, "Dimensional synthesis of wideband waveguide filters," 2004 IEEE MTT-S Symposium Digest, Vol. 2, 463-466, Jun. 2004.
5. Vanin, F. M., D. Schmitt, and R. Levy, "Dimensional synthesis of wideband waveguide filters and diplexers," IEEE Trans. on Microwave Theory and Techniques, Vol. 52, No. 11, 2488-2495, Nov. 2004.
6. Cameron, R. J., R. R. Mansour, and C. M. Kudsia, Microwave Filters for Communication Systems: Fundamentals, Design and Applications, Hardcover, Jul. 27, 2007.
7. Matthaei, G. L., L. Young, and E. M. T. Jones, "Microwave Filters, Impedance-matching Networks and Coupling Structures," McGraw-Hill, New York, 1964.
8. Morini, A., T. Rozzi, and M. Morelli, New formulae for the initial deisgn in the optimization of T-junction manifold multiplexers, 1997 IEEE MTT-S International Microwave Symposium Digest, Vol. 2, 1025-1028, Jun. 1997.
9. FEST3D, Fullwave electromagnetic simulation tool, www.fest3d.com.