A comparison of CAD models and experimental results for some passive microwave circuits.

摘要

Passive RF and microwave components printed on microstrip circuit boards are essential elements of microwave circuits. Creating approximate closed-form solutions for the electrical characteristics in terms of S-parameters for these components and finding the appropriate microwave simulator to produce reasonably accurate results can be a challenge. In this thesis, we go through the design, simulation and S-parameters bench measurements of four commonly used passive microwave components and compare their simulation results to their laboratory measurements results. The four circuits studied in this work are: Stepped-Impedance (hi-Z, low-Z) low pass filter, edge coupled-line band pass filter, 3-dB 90° hybrid and a rectangular patch antenna. The two simulation packages used to design these components are PUFF (from California Institute of Technology), and the student version of Serenade (from Ansoft). The results of the study conducted on all four components show that unlike PUFF, Serenade predicted more reasonable and comparable results to the bench measurements. It is worth mentioning that there are slight differences between the Serenade simulation results and their corresponding bench results, such as frequency shift, insertion loss and return loss, but are less significant than those obtained from PUFF.