Instead of switching the antenna beam between two different positions the beam position is steered continuously.
- As shown in fig. a cassegrain feed with rotating sun-reflector is used to generate conical scan antenna beam.
- A generator produces two sinusoidal reference signals at rotation frequency fs 900 out of phase with each other.
- These are applied to the phase sensitive detectors for the incoming echo intensity received through range gate.
- These error signals are amplified by servo amplifiers to drive the azimarh and elevation motors.
- The position of rotation axis of antenna beam in iteration and azimuth are displayed by making use of potentiometers.
Optimum Squint angle:
If the squint angle in conical tracker is greater, it prodeces greater slope of error signal around the boresight and more accurate angle measurement results. The maximum slope of error signal occurs when squint angle becomes 0.41 of the half power of the beam width.