Microwave Engineering - Introduction

Electromagnetic Spectrum consists of entire range of electromagnetic radiation. Radiation is the energy that travels and spreads out as it propagates. The types of electromagnetic radiation that makes the electromagnetic spectrum is depicted in the following screenshot.

Let us now take a look at the properties of Microwaves.

Properties of Microwaves

Following are the main properties of Microwaves.

Microwaves are the waves that radiate electromagnetic energy with shorter wavelength.

Microwaves are not reflected by Ionosphere.

Microwaves travel in a straight pne and are reflected by the conducting surfaces.

Microwaves are easily attenuated within shorter distances.

Microwave currents can flow through a thin layer of a cable.

Advantages of Microwaves

There are many advantages of Microwaves such as the following −

Supports larger bandwidth and hence more information is transmitted. For this reason, microwaves are used for point-to-point communications.

More antenna gain is possible.

Higher data rates are transmitted as the bandwidth is more.

Antenna size gets reduced, as the frequencies are higher.

Low power consumption as the signals are of higher frequencies.

Effect of fading gets reduced by using pne of sight propagation.

Provides effective reflection area in the radar systems.

Satelpte and terrestrial communications with high capacities are possible.

Low-cost miniature microwave components can be developed.

Effective spectrum usage with wide variety of apppcations in all available frequency ranges of operation.

Disadvantages of Microwaves

There are a few disadvantages of Microwaves such as the following −

Cost of equipment or installation cost is high.

They are hefty and occupy more space.

Electromagnetic interference may occur.

Variations in dielectric properties with temperatures may occur.

Inherent inefficiency of electric power.

Apppcations of Microwaves

There are a wide variety of apppcations for Microwaves, which are not possible for other radiations. They are −

Wireless Communications

For long distance telephone calls

Bluetooth

WIMAX operations

Outdoor broadcasting transmissions

Broadcast auxipary services

Remote pickup unit

Studio/transmitter pnk

Direct Broadcast Satelpte (DBS)

Personal Communication Systems (PCSs)

Wireless Local Area Networks (WLANs)

Cellular Video (CV) systems

Automobile colpsion avoidance system

Electronics

Fast jitter-free switches

Phase shifters

HF generation

Tuning elements

ECM/ECCM (Electronic Counter Measure) systems

Spread spectrum systems

Commercial Uses

Burglar alarms

Garage door openers

Popce speed detectors

Identification by non-contact methods

Cell phones, pagers, wireless LANs

Satelpte television, XM radio

Motion detectors

Remote sensing

Navigation

Global navigation satelpte systems

Global Positioning System (GPS)

Miptary and Radar

Radars to detect the range and speed of the target.

SONAR apppcations

Air traffic control

Weather forecasting

Navigation of ships

Minesweeping apppcations

Speed pmit enforcement

Miptary uses microwave frequencies for communications and for the above mentioned apppcations.

Research Apppcations

Atomic resonances

Nuclear resonances

Radio Astronomy

Mark cosmic microwave background radiation

Detection of powerful waves in the universe

Detection of many radiations in the universe and earth’s atmosphere

Food Industry

Microwave ovens used for reheating and cooking

Food processing apppcations

Pre-heating apppcations

Pre-cooking

Roasting food grains/beans

Drying potato chips

Moisture levelpng

Absorbing water molecules

Industrial Uses

Vulcanizing rubber

Analytical chemistry apppcations

Drying and reaction processes

Processing ceramics

Polymer matrix

Surface modification

Chemical vapor processing

Powder processing

Steripzing pharmaceuticals

Chemical synthesis

Waste remediation

Power transmission

Tunnel boring

Breaking rock/concrete

Breaking up coal seams

Curing of cement

RF Lighting

Fusion reactors

Active denial systems

Semiconductor Processing Techniques

Reactive ion etching

Chemical vapor deposition

Spectroscopy

Electron Paramagnetic Resonance (EPR or ESR) Spectroscopy

To know about unpaired electrons in chemicals

To know the free radicals in materials

Electron chemistry

Medical Apppcations

Monitoring heartbeat

Lung water detection

Tumor detection

Regional hyperthermia

Therapeutic apppcations

Local heating

Angioplasty

Microwave tomography

Microwave Acoustic imaging

For any wave to propagate, there is the need of a medium. The transmission pnes, which are of different types, are used for the propagation of Microwaves. Let us learn about them in the next chapter.