In article , Ron Natalie
wrote:
The glide slope transmitter is often separate.
It's always separate. The glide slope transmitter is down approximately
where the touchdown is (and obviously off to the side of the runway).

Not only is the G/S transmitter separate, the signal is bounced off the
ground from the transmitter toward the approach end of the runway. That
is why TERPS requires a specified distance of flat empty ground ahead
of the runway threshhold.