PIN Diode T-R Switch for use with RF Power Amplifier
The pin diode T-R switch is a 3 port device, which means that your circuit would actually look like this:



The T-R switch with the quarter wavelength section commonly comes up in literature on the web, because it is the easiest to implement, needing only a single bias current to control the SPDT switch.

The downside to this simplicity is that the isolation is quite poor, 20 to 25dB, which means that a considerable proportion of your 30W Tx power will leak into your receiver, and could cause damage.

A better pin-diode switch configuration, with isolation around 40 to 50dB is shown here:



An additional benefit of this arrangement is its wide-bandwidth, due to no quarter wavelength line.

The downside here is complexity - extra components, and two bias currents which must be driven at the same time in opposite directions. It is common to use a small transistor configuration to control the switching of these bias currents to ensure that the switching of all pin diodes happens at precisely the same time.

Some excellent sources of free and practical information about pin diode switches are the Pin Diode Circuit Designer's Handbook and Skyworks Design With Pin Diodes application note