Antennas Part 4 Coordinates Solid Angle Coordinate Review Analysis of Array

Coordinates:

Solid Angle Each of these antenna appears as a point source far from the array

Analysis of Array Note: The Group Pattern (AF) is only for the Electric Field. For Radiated Power, F array = |AF| 2 The total E-field pattern can Be found as shown: I 1 =I o  α degrees; I 2 =Io  0 degrees; Unit Pattern is for E-field of Single element

Analysis of Array This is the Antenna Factor for the E or H fields! The power pattern is found using:

Example For the 2 element array shown, sketch the normalized E-field and power pattern when the currents are: (a) fed in phase, (b) fed 90 o out of phase AF = 2cos(.5(Bd + α)), Unit Pattern = cos(θ) E nor = cos(θ)cos(.5(Bd +α)),