P RESENTATION ON MONOLITHIC MICROWAVE INTEGRATED CIRCUITS PASSIVE COMPONENTS SUBMITTED BY:- AJAY KAUSHIK(088/ECE/09 ) NAMAN KUMAR(082/ECE/09 )

MICROWAVE INTEGRATED CIRCUITS MIC’s are designed for operation at frequencies of approximately 1GHz or more. Such components are physically small, in some cases having less than 1sq.mm of surface area. An MIC can contain an entire electronic device on a single semiconductor. Types of MIC:- -Hybrid Microwave Integrated Circuits. -Monolithic Microwave Integrated Circuits.

M ONOLITHIC M ICROWAVE I NTEGRATED C IRCUITS They are a most recent development, where all active and passive circuits are grown or implemented in the substrate. MMIC’s can be made at lower cost because manual labor required for HMIC is eliminated. A single wafer contain can contain a large number of circuits, which can be processed and fabricated simultaneously.

A MMIC is a integrated circuit device that operates at microwave frequencies(300MHz to 300GHz). These devices can perform functions such as:- -microwave mixing -power amplification -low noise amplification -high frequency switching Inputs and outputs on MMIC devices are frequently matched to a characteristic impedance of 50 ohms.

This makes them easier to use, as cascading of MMIC’s does not require external matching network. Additionally most microwave test equipment is designed to operate in a 50 ohm environment. MMIC’s are dimensionally small (from around1mm ² to 10mm²) and can be mass produced. This has allowed proliferation of high frequency devices such as cellular phones.

MATERIALS USED IN MMIC’ S : MIC’s originally were fabricated using III-V group compound semiconductors(for substrate only) such as GaAs. GaAs has two advantages over Si, the traditional material for IC realization: device speed and a semi insulating substrate. InP offer superior performance to GaAs. GaN is an option because GaN transistors can operate at higher temperature and voltages than GaAs.

FABRICATION PROCESS Designing of MMIC requires extensive use of CAD software. It includes circuit design & optimization and mask generation. Formation of active layer on substrate by using either ion implantation or epitaxial technique. Isolation of active areas is done through etching.

 Small size.  Since it is easy to fabricate additional FET’s in an MMIC.  Circuit performance and flexibility can be enhanced with little additional cost.  Less parasitic reactance.  Low yield due The effects of component tolerance and discontinuities.  Waste of large areas of relatively expensive substrate.  Trimming after fabrication is difficult.  Inherent losses and small size limits heat dissipation. ADVANTAGESDISADVANTAGES

APPLICATIONS OF MMIC MMIC technology will facilitate exploitation of 50 to 500GHz spectrum.  optical and broadband communications.  low noise amplifiers.  low cost packaging for transmitting and receiving new 20/30GHz system.

W HY G A A S MMIC GaAs has become the material of choice because of its ability to perform at high frequencies. Size and weight reduction. Cost reduction for medium-to-large production volumes. Wider frequency bandwidth performance. High resistivity semi-insulating property that reduces cross talk between devices.

S OFTWARES USED FOR DATA ANALYSIS AND DESIGN Designer must be able to take ideas for the circuit topology and predict performance. This is achieved using CAD tools. High yield MMIC product requires well characterized and accurately modeled MMIC. The interaction of closely spaced components on the chip can also be simulted using 3D simulation.

O RIGIN SOFTWARE Proprietary computer for interactive scientifec graphing and data analysis. Produced by Origin Lab Corporation,and runs on Microsoft Windows. Data analysis involves:-  curve fitting and peak analysis.  curve fitting performed by non linear square filters.  Files are imported in various formats which are to be analyzed.

Origin is primarily a GUI software. Origin has scripting language for controlling the software. Origin is used for studying the nature of a particular graph and its behavior after the alterations. Large amount of data can be analyzed using this software and we can generate easily understandable equations. It can also be used to generate graphs from raw data and study the data modifications.

R AW DATA

G RAPHICAL STUDY FROM THE DATA