For the sake of simplicity I have used "passive repeater" here to refer to microwave reflectors only, but the same term is also used for arrangements of two antennas connected back-to-back. These are much more common in VHF/UHF than in the microwave, although microwave passive repeaters of two parabolic antennas have been used in limited cases.
Comments
Shown are reflectors. Two dishes back to back is possible too. Our telco had such an array on top of a mountain to jump over it.
It's mentioned in the end notes:
For the sake of simplicity I have used "passive repeater" here to refer to microwave reflectors only, but the same term is also used for arrangements of two antennas connected back-to-back. These are much more common in VHF/UHF than in the microwave, although microwave passive repeaters of two parabolic antennas have been used in limited cases.