MMIC(Monolithic Microwave

integrated circuits)

ANKIT KUMAR PANDEY

M.TECH(2ND YR)

ALLAHABAD

UNIVERSITY1

Microwave Integrated Circuits

(MIC’s)There are three types of circuit elements that either are used in chipform

or are fabricated in MIC. They are:

– Distributed transmission lines (microstrip, strip, etc.)

– Lumped elements (R, L. and C)

–Solid state devices (FETs, BJTs, diodes, etc.)

Two types of MICS are-

1. Hybrid Microwave Integrated Circuits (HMICs)

2. Monolithic Microwave Integrated Circuits (MMICs):

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MMIC (Monolithic Microwave integrated

circuits)

The world monolithic is derived from the Greek letter monos (Single) and lithos

(stone). Thus a monolithic integrated circuit is built on a single crystal.

MMICs, or Monolithic Microwave Integrated Circuits, are a type of integrated

circuit (IC) device that operates at microwave frequencies (300 MHz to 300 GHz).

These devices typically perform functions such as microwave mixing, power

amplification, low noise amplification, and high frequency switching.

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MMICs are dimensionally small (from around 1 mm² to 10 mm²) and

can be mass produced, which has allowed the proliferation of high

frequency devices such as cellular phones.

This makes them easier to use, as cascading of MMICs does not then

require an external matching network.

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Structure of Monolithic MIC

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Materials for Monolithic Microwave

Integrated Circuits

Substrate material:- alumina, beryllia, ferrite/garnet, GaAs, glass,

rutile

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Conducting material:- aluminum, copper, gold, silver . It should have

following properties;

Dielectric films:- Al2O3, SiO, SiO2, Si3N4 and Ta2O5

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Resistive films:- Cr, Cr-SiO, NiCr, Ta and Ti

Resistive materials are used in MMIC for bias networks,

terminators and attenuators.

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Advantages of MMIC

Low cost (because of the large quantities processed)

Small size

Light weight

High reliability; all components are fabricated simultaneously

and there are no soldered joints.

Improved reproducibility

Improved performance

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Disadvantages of MMIC

Processing difficulties.

Low yields because of

The effects of component tolerance & discontinuities.

Trimming after fabrication is difficult.

Inherent resistive losses.

Small size limits heat dissipation.

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Applications of MMIC

MMICs are suitable for space and military applications because they meetthe requirements for shock, temperature conditions, and severevibration. These are the major factor in the success of MMICs fordevelopment of microwave solid state devices.

Communications

Next generation compact radio

Optical and broadband microwave communications

Homeland Security Scanners

Portal security scanners

Stand-off security cameras for public places

Handheld detectors for police and special forces

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Imaging & Sensors

Missile sensors

Environmental sensing

Explosives

Medical imaging

New Applications

Automotive collision avoidance radar

Airport runway debris detection

Helicopter & aircraft blind landing systems

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References;

RFIC and MMIC Design and Technology published by

the IEE (London) ISBN 0-85296-786-1

Practical MMIC Design published by Artech

House ISBN 1-59693-036-5 Author S. P. Marsh

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