Unidirectional broadband microstrip antenna for through walls radar application

We present a design and simulation of broadband microstrip antenna with unidirectional radiation pattern for through walls radar application. Design and simulation with computer was confirmed the implementation of the proposed design. The results were validated by measurements in the laboratory. This research is a continuing from our previous research in developing antennas for through walls radar application. In previous research, we have developed a broadband microstrip antenna for through walls radar application in a bidirectional radiation pattern. Based on the laboratory experiment results, bidirectional radiation pattern still have weaknesses on detecting objects movement behind radar antenna. Unidirectional antenna has proven to have greater gain than bidirectional antenna. To obtain unidirectional radiation pattern antenna we added reflector behind the antenna to detect moving objects from in front of the antenna only. The previous bidirectional antenna for through walls application showed 4-5 dBi gain. In this research, the design and simulation of unidirectional antenna for through walls application showed 5.5 to 7.5 dBi gain. The unidirectional antenna will be printed using FR4 material with a dielectric constant and substrate thickness of 4.4 and 1.6 mm respectively. This antenna has a bandwidth of 1.5 GHz (66.67%) with frequency of 1.5 to 3 GHz.