Dual-band microstrip antenna design

Abstract

Multi-frequency microstrip antennas are very much in demand due to their physical and mechanical properties like small size, lightweight, thin profile, low power consumption, and ease of implementation in the domestic applications. Some designs of dual-band microstrip patch suitable for GSM 900/1800 base station operation are already a research topic. Dual frequency microstrip antennas are also used in GPS and SAR. Commercially, these are deployed in RFID tags. But for the antenna to be useful in all these applications, its behavior like return loss, bandwidth, beam width, radiated power, gain, and directivity, at both the frequencies, should be nearly identical. The purpose of this work is to design the microstrip patch for dual frequencies of 945 MHz and 1960 MHz. Two new approaches called Coplanar patches and Overlapped patches are proposed. Then some of the existing techniques like Stacked patches, Dual slot loaded patches and Dual frequency PIFA are explored for our design specifications. Finally, the comparison of all the design aspects including the proposed ones is carried out in this work.