Analysis of microstrip antennas integrated with feed networks

摘要

It has often been claimed that the microstrip antenna can be easily integrated with the feed network and circuitry on the same substrate. However, if this is actually done some compromise must be made between a good antenna performance and an acceptable circuit behavior [1]. The root of this problem lies in the fact that antenna radiation and circuitry are distinct electrical functions. Antennas require loosely bound fields for radiation into space, hence suggests the use of an electrically thick substrate with low ∊r. On the other hand a microwave circuit requires tightly bound fields to prevent undesired radiation or coupling, suggesting the use of dectrically thin, high ∊r substrates, which in turn degrades the antenna performance.