Design of Quad feed end-fire microstrip patch antenna for Airborne Systems

Abstract

To design a quad feed end-fire microstrip patch antenna for airborne systems. Basically these type of antennas are most helpful for avoiding mid-air collisions between aircraft. The microstrip patch antenna is very small in size and it is less in weight. Due to small size and less weight, it offers an easy design and fabrication process. The microstrip patch antenna has radiating patch on one side and ground on the other side. They operate at microwave frequencies. The low profile structure of microstrip antenna offers its wide use in wireless communication. They are used as communication antenna on missiles. Traffic alert and Collision Avoidance System (TCAS) is an airborne system which is utilized to provide the service as last defense equipment for avoiding mid-air collisions between the aircraft. 1.03 GHz and 1.09 GHz are the transmitting and receiving frequencies of the existing TCAS antenna respectively. In airborne systems, low aerodynamic drag is required. FR4 epoxy is chosen as the substrate material whose dielectric constant is 4.4. 1.06GHz is chosen as the design frequency, since it is centre frequency between 1.03GHz and 1.09GHz. Microstrip patch antenna always radiates in the broadside direction which is along elevation plane. Due to metallic cap, microstrip patch antenna can also radiate in the end fire radiation which is along the azimuth plane. The ground plane must have very large dimensions than the patch. This microstrip patch antenna working at UHF (Ultra High Frequency) band is designed and their parameters like gain, directivity, return loss, VSWR (Voltage Standing Wave Ratio) and radiation pattern have been analyzed and simulated using ANSYS HFSS (High Frequency Structure Stimulator).