Circularly polarized broadband high-efficiency active integrated antenna

This letter presents a circularly polarized (CP) broad-band high-efficiency active integrated antenna, where the broadband CP antenna is integrated directly with a broadband high-efficiency class-E power amplifier (PA). To achieve CP operation, a series feed using an L-shaped microstrip feed line below the ground plane is used to provide a 90 degrees phase shift between crossed slots. The antenna serves both functions of a broadband CP radiator and a broadband harmonics-termination load network for the class-E PA. Measures results demonstrate both broadband CP radiation and high efficiency. (c) 2006 Wiley Periodicals, Inc.