Spring 2008
Antenna Topics
Radiation zone
Near zone
Application of formulas for E and H fields of an accelerated
charge in the radiation zone
Radiation intensity
Relation to Poynting vector
Directive gain
Relation to radiation intensity and total power
Directivity
Examples of antennas (Poynting vector, radiation intensity,
directive gain and directivity):
Hertzian dipole (current form)
Electric and magnetic fields
Power radiated given current, h and wavelength
Dipole antennas
Directive gain and directivity for half-wave dipole antenna
Effective area
Relation to directive gain
Friis transmission formula
Find maximum range given powers and directivities
Find one power given other power, range and directivities
Decibel measurements of power ratios
3 dB = factor of 2
10 dB = factor of 10
20 dB = factor of 100
30 dB = factor of 1000, etc.
Antenna arrays
Radiation intensity as product of array pattern and single-element
radiation intensity
Array patterns for linear arrays
Log-periodic antenna arrays