RF Transistor catalogs from multiple manufacturers have been listed on everything RF. You can use the filters on the left (above) to narrow down the list of transistors. You can download datasheets, get quotes and pricing on the matching parts. Some parameters that are imposrtant when looking for rf transistors are:
1. Transistor Type: This is the technology the transistor has been built on - GaN, LDMOS, MOSFET, BiPolar etc. are some of the options.
2. Frequency (MHz): This is the frequency band at which the transistor can operate.
3. Gain (dB): This is the level of gain the transistor can provide.
4. Voltage (V): This is the supply voltage required by the transistor
Use the parametric search tool on everything RF to find rf transistors that meet your requirement.