Hybrid microwave integrated circuits (HMICs)

Abstract

This paper presents systematic approach of material selection for substrate material in hybrid microwave integrated circuits (HMICs). The performance of HMICs starts deteriorating at microwave frequencies because the circuit dimensions become comparable to the wavelength. So, it is important to design HMICs in such a way that its performance remains unaffected even at high frequencies. One way to fulfil this requirement is to fabricate a proper device. For this, substrate material in HMICs plays an important role. But there are different types of materials available which can be used as substrate material of HMICs. The commonly reported materials are: Silicon (Si), Gallium Arsenide (GaAs), Indium Phosphide (InP), Alumina (Al2O3), Beryllia, Fused Silica, Sapphire, Woven PTFF/Glass, PTFE/Glass, Polyolefin, and Ferrite/Granite. As each material is having its own advantages and limitations; therefore, it is important to choose the best possible material out of all possible materials. For this purpose two decision making techniques are used