Theoretical and experimental study of feed network effects on the radiation pattern of series-fed microstrip antenna arrays

Microstrip series-fed arrays are often utilised for compact array designs. This type of feed structure minimises feedline lengths and feedline radiation. However, in practice, the radiation from the feed network still can be significant and it can have a noticeable effect on the array radiation pattern. Analysis is performed using the advantageous full-wave discrete image technique. Theoretical and experimental analysis of the radiation from a four-element series-fed microstrip array antenna, which fully includes the effect of the feed network, is presented. General conclusions are made for the purpose of practical designs.