Which of the following is not a principle shape factor?

Azimuthal direction of maximum fading
Angle of arrival
Angular spread
Angular constriction

The correct answer is D. Angular constriction.

The principle shape factors are:

  • Azimuthal direction of maximum fading: The direction in which the received signal is strongest.
  • Angle of arrival: The angle at which the received signal arrives at the receiver.
  • Angular spread: The angular width of the main lobe of the received signal.

Angular constriction is not a principle shape factor because it is not a measure of the shape of the received signal. It is a measure of the strength of the received signal in different directions.