Design of Low-Profile Microstrip Antenna with Enhanced Bandwidth and Reduced Size

An effective technique is presented to enhance the bandwidth and reduce the size of an ultralow-profile microstrip antenna. By loading multicouple staggered slots on the patch and using inset feed structure, two TM10modes can be excited at two close frequencies and matched well simultaneously. Designs based on the structures with four-, five-, and six-couple staggered slots have been made to demonstrate the effective technique. To the best designed results, the presented ultralow-profile microstrip antenna obtains a bandwidth enhancement of about two times and a size reduction of about 60% compared with the ordinary one. The technique is suitable for radio-frequency front-end antenna integration and package in microwave and millimeter-wave bands