Antennas and Wave Propagation

Contains

1-1 INTRODUCTION AND DEFINITIONS:
1-1-1 THE ELECTROMAGNETIC SPECTRUM
1-1-2 THE RADIO TRANSMITTER
1-1-3 THE RADIO RECEIVER
1-1-4 WIRELESS COMMUNICATION SYSTEMS
1.2 MAXWELL’S EQUATIONS AND THE FUNDAMENTAL OF RADIATION:
1-2-1 UNIFORM PLANE WAVE (UPW) SOLUTION
1-2-2 PROPAGATION IN LOSSLESS, CHARGE-FREE REGION
1-2-3 POYNTING VECTOR
2-1 RADIATED FIELD OF A HERTZIAN DIPOLE
2-1 BASIC ANTENNA PARAMETERS:
2-1-1 DIRECTIVITY AND GAIN:
2-1-2 RADIATION RESISTANCE:
2-1-3 EFFECTIVE AREA OF AN ANTENNA:
2-1-4 EFFECTIVE LENGTH/HEIGHT OF THE ANTENNA:
2-1-5 ANTENNA EQUIVALENT CIRCUIT:
3-1 HALF WAVE DIPOLE ANTENNA:
3-2 QUARTER WAVE MONOPOLE ANTENNA:
4-1 SMALL LOOP ANTENNAS:
5-1 INTRODUCTION TO ANTENNA ARRAYS:
5-2 ARRAY OF IDENTICAL ELEMENTS:
5-3 TWO-ELEMENT ARRAY:
5-3-1 CASE-1:
5-3-2 CASE 2:
5-4 UNIFORM ONE-DIMENSIONAL ARRAY
5-4-1 BROAD SIDE CASE:
5-4-2 END FIRE CASE:
5-5 ARRAY PATTERN SYNTHESIS:

1-1 INTRODUCTION AND DEFINITIONS:
There are more “radios” being built than ever before!
1. Telephony
1. Cellular
2. Public Cabinets System (PCS)
3. Global Satellite Systems
4. Microwave Links
2. Broadcasting
1. AM radio, FM radio, VHF/UHF TV
2. Satellite Links
3. Direct Broadcasting
3. Networking
1. LAN
2. WiFi
3. WiMAX
4. LiFi
4. Radar and Navigation
1. Global Positioning System (GPS)
2. Radar detection, tracking and imaging
3. Radio Frequency Identification (RFID)
Q: Just what is a radio?
A: A device that transfers information to a distant site, by means of unbounded electromagnetic propagation.
A radio system has three sections, with antennas serving as couplers between each section:


1-1-1 THE ELECTROMAGNETIC SPECTRUM
We can propagate energy anywhere within the electromagnetic spectrum, but we typically use frequencies less than, say, 40 GHz.
Q: Why don’t we use frequencies greater than 40 GHz ?
A: Two reasons:
1. The difficulty in making electronic components.
2. The Earth’s atmosphere rapidly attenuates the propagating wave!