Abstract: | This paper describes a technique for using twin element antennas (dipoles and slots) to increase the efficiency of antennas fabricated on electrically thick dielectric substrates. We present calculations which show that the efficiency of both the slot and dipole antennas can be increased by the proper spacing of elements placed broadside to each other. We consider the use of substrates that are odd integral multiples of a quarter of a dielectric wavelength thick and give results for an =4 substrate with thicknesses of one, three, and five quarter wavelengths. These thicknesses can be used when working at millimeter wave frequencies and yield substrate dimensions which can be handled and processed easily, while still yielding radiation-to-air efficiencies of about 70%. We also show calculated beam patterns for the elements which appear to be suitable for imaging array applications.This work was supported by the Joint Services Electronics Program, program no. AFOSR-F49620-86-C0045, and the National Science Foundation under grant number ECS-8552868. |