A linearly polarized active integrated square microstrip patch antenna

A simple and symmetric active integrated antenna design is presented. The antenna with harmonic suppression capability is directly integrated with a class B amplifier for reduced size and improved power added efficiency. The antenna is a square microstrip patch with harmonic suppressing slits etched on it. The antenna is linearly polarized, but the design can be conveniently modified to circular polarization because of the symmetric antenna geometry. The antenna design, integration with amplifier, and the measurement results are presented. It is found that due to the harmonic suppression, the improvement in power added efficiency is about 5%. In addition, the antenna performance is good and is not disturbed by the added harmonic suppressing slits.