Full-wave computer-aided design of waveguide components by circuit simulation

✍ Scribed by A. Weisshaar; M. Mongiardo; V. K. Tripathi

• Publisher: John Wiley and Sons
• Year: 1998
• Tongue: English
• Weight: 231 KB
• Volume: 8
• Category: Article
• ISSN: 1096-4290
• DOI: 10.1002/(sici)1099-047x(199805)8:3<236::aid-mmce7>3.0.co;2-h

✦ Synopsis

This article reviews a full-wave equivalent circuit formulation for a large class of rectangular waveguide components and its implementation in a commercial circuit simulator. The full-wave equivalent circuit formulation represents a direct implementation of the mode-matching technique in terms of ideal dependent voltage and current sources and modal transmission lines. It enables rigorous and efficient full-wave analysis of waveguide components such as iris-coupled filters, metal insert filters, couplers, and phase shifters, directly and entirely by circuit simulation. In addition, available design and optimization features of the CAD tool can be fully exploited. The paper reviews the derivation of the equivalent circuit models for single and cascaded step discontinuities and describes the generalization to single and cascaded bi-and n-furcations including metal inserts. The method has been implemented in the microwave circuit simulator Libra and applied to several waveguide structures, including a four-iris bandpass filter for the Ka-band. Excellent agreement between the circuit simulation solutions and the results from a stand-alone mode-matching code is found. To demonstrate the design capabilities with the circuit simulation approach, the bandpass filter has been redesigned and optimized by using the available design and optimization features of the commercial CAD tool.