Improvement in Gain of Dipole and Yagi-uda Based microstrip fed patch Antenna

摘要

A low cost and geometrically simple microstrip fed based patch antenna using a concept of dipole and yagi-uda is proposed as a feed antenna of a parabolic reflector antenna. The proposed antenna structure is like a dipole antenna that is printed in the form of mictrostrip patch antenna. It has two dipole arms one is below the substrate and other is above the substrate. A thin microstrip line is used as a feed of the system with the ground plane is used such that it provides impedance matching with the feed and does not cause any inconvenience in back radiation by the dipole reflector. Dipole reflector is made like a yagi-uda antenna structure and its geometry provides both front and back the radiations so that there is minimum blockage occurs in parabolic reflector antenna. It is fixed at the focus of the parabolic surface of reflector using only a single strut for the support. It provides 7 dBi of gain as a feed and 94 % of total efficiency. The operating range of frequency is 2 GHz to 4 GHz but its best performance is shown at 3.3 GHz.