Simplifying Assumptions
Transmission medium is non-dispersive and uniform
- the effects of slightly different paths from a source to the various points on the receiving aperture are insignificant.
Far field
- allows signals to be treated as plane waves
- signal magnitude across the antenna is uniform, only phase varies
Signals are narrow-band relative to the carrier
- time delay can be approximated by a phase shift
- antenna patterns are approximated by CW antenna patterns