I am planning to use RF Switch FDG6324L for a transceiver application. For this switch, can I use input output interchangably or is it directional (one way)?
Any FET switch has input/output interchangeable.
The switch you posted can work at maximum few kHz.
For RF (maximum ~50MHz) you can use one of the bus switches also from Fairchild.
There are lots of RF switch vendors out there, just fire up your favorite search engine (or start with someplace like globalspec.com).
Check this little guy out: https://www.minicircuits.com/pdfs/VSW2-33-10W+.pdf
Thanks for mtwieg and enjunear, I think use PIN diode is a good choice. But if I use FET, there is a parasitic diode, and through the Source and Drain is sine wave, so in half period the parasitic diode will be break, how to solve this problem?
The substrate diode is characteristic for power MOSFET geometry that have substrate and source connected. It's not necessary for MOS analog switches with a separate substrate terminal.
If you wan't to use power MOSFET as AC switches, two devices have to be connected in an anti-series configuration. You can refer ro MOS AC solid state relays as an example. In any case, you should double check if a power MOSFET provides sufficient isolation at your frequency of interest.