Familiarization with the Microwave Laboratory Equipment.

What ferrite device can be used instead of duplexer of isolate microwave transmitter and receiver when both are connected to the same antenna?
Which of the following permits a microwave signal to travel in one direction with virtually no loss, but severely attenuates any signal attempting to travel in the reverse direction?
A PIN diode consists of ______number of semiconductor layers.
In Microwave we consider the elements as
A circulator device can also used as an isolator with a few modifications.