Transmission Media

Microwave Link Budget

Akram Radhi Nasser Master of Electronic and Communication

First course

What is a Microwave? *It’s electromagnetic waves with a short

wave length between radio waves and infrared radiation .

*The microwave radiation means electromagnetic radiation arising from radiation electric waves of high frequency value ranging between approximately (1 - 300) GHz.That is, they include a range of radiation wave length of (30 – 0.1) centimeter

*Radio waves are bounded it from below (larger wave-length) and is bordered by infrared that reduce the visible light spectrum of the highest (along with smaller) wave.

Microwave Applications

What is Link Budget ? *A link budget is accounting of all of the

gains and losses from the transmitter, through the medium to the receiver in a .telecommunication system

*It accounts for the attenuation of the transmitted signal due to propagation, as well as the antenna gains, feedline and

miscellaneous losses  .

A simple link budget equation

Received Power (dB) = EIPR (dB) − Losses (dB)

Concept and parameters **EIPR :

EIRP: Effective Isotropic Radiated Power EIRP = Transmit power (fed to the antenna) + antenna gain

LTX = transmitter losses (coax, connectors...) (dB)

**Path Losses: The loss due to propagation between the transmitting and receiving antennas, often called the path loss or free space loss

[LOSSES[ =]FSL[ + ]RFL[ + ]AML[ + ]AA[ + ]PL ,]where :

_[FSL = ]free‐space spreading loss in dB =PT/PR(in w

atts)[ –RFL = ]receiver feeder loss in dB

[ –AML = ]antenna misalignment loss in dB[ –AA =]atmospheric absorption loss in dB

[ –PL = ]polarization mismatch loss in dB

where Lfs is expressed in dB, D is in Kilometers or Miles and fis in GHz.

General Equation *General equation for calculate received

power

References: 1 -https://en.wikipedia.org/wiki/Microwave

2 -https://en.wikipedia.org/wiki/Link_budget

3 ”-Link budget “ , PROF. MICHAEL TSAI, 2011

4 -https://en.wikipedia.org/wiki/Free-space_path_loss

5”-Link Budget Calculation”, The abdus Salam The International center of

theoretical physics

THE END