How can a microwave communication link operating at 5 Gigahz go farther Would increasing transmission power extend its range or a high gain antenna be effective as well?

Answer 1

Both. Increasing the gain is like driving a dumptruck down the street, but its going to cause alot of damage. Increasing the gain on your antenna can hear everything like putting a horn to your ear, but you risk damaging your ear drum.

Similarly, boosting the gain on your transmitter can result in jamming like RF devices within the transmitted frequency band. This could end up resulting in an FCC violation. Increasing the gain of your receiver can result in lowering the signal to noise ratio. This will result in rising the noise floor and receiving high static fundamentally losing the signal in the noise.