Analysis and Design of Triplate Corporate Feeds at High Frequencies

The analysis and design of an integrated triplate corporate feed for a microstrip antenna array has been examined. A mode matching technique is used to calculate the reactive behaviour of each junction and taper in the feed and the results are compared to those obtained using static approximations. The spurious radiation generated at the triplate to microstrip interface is also estimated and methods of reduction are considered. The measured phase and amplitude characteristics at 17GHz, of feeds manufactured using computer graphic production incorporating the phase corrections obtained from the mode matching method are given. The limiting performance levels due to manufacturing tolerances, spurious mode generation and radiation loss are estimated.