x band autotrack feed (Help me I'm lost)

Dear All,
We have an X band Cassegrain Antenna which tracks a LEO satellite using Program Track.
Now we need to add AutoTrack capability to the system.

I'm completely lost which equipment to use.
I've found the following:
1. Single Channel Monopulse (SCM)
2. Monopulse Comparators
3. TE21 Monopulse Tracking Couplers

I couldn't find equipment for Single Channel Monopulse,
Monopulse Comparators have 4 inputs so theres a need to modify the X band feed, Couldn't figure out how to modify the X band feed to input the 4 Input ports.
Don't know which output port should be connected to the LNA and what to do with the others.
Do I need TE21 Monopulse Tracking Couplers and how to Interface them with the feed?
Please Help I'm lost