Wave Propagation

NANYANG TECHNOLOGICAL UNIVERSITY

School of Electrical and Electronic Engineering

Laboratory Experiment

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------------------------------------------------- Experiment NO. 315
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EE3071 Laboratory 3

Location: S1-B4a-03

AY 2011/2012

Name: EMIR NUROV
Matriculation number: U0920108K
Group: LA03

1. Introduction

1.1 Propagation in Free-Space

1.1.1 Friis Transmission Equation

To begin the derivation of the Friis Equation, consider two antennas in free space (no obstructions nearby) separated by a distance R: Figure 1. Transmit (Tx) and Receive (Rx) Antennas separated by R.
Assume that Watts of total power are delivered to the transmit antenna. For the moment, assume that the transmit antenna is omnidirectional, lossless, and that the receive antenna is in the far field of the transmit antenna. Then the power density p (in Watts per square meter) of the plane wave incident on the receive antenna a distance R from the transmit antenna is given by: If the transmit antenna has an antenna gain in the direction of the receive antenna given by, then the power density equation above becomes: The gain term

References: Data from Kittel, Introduction to Solid State Physics, 7th Ed. Referenced to G. T. Meaden, Electrical resistance of metals, Plenum, 1965.