Does the PD55003-E Work For 55-57 MHz Frequencies?

[ejfowler7]

I'm currently working on an amplifier stage for a COHO Driver. I'm posting with a general question on the characterization for this transistor. The PD55003-E came up as a candidate for my coherent oscillator amplifier stage. Since the FET's datasheet specifies higher frequencies I was wondering if there were any tests done rated around 55-59 MHz with a Class A amplifier. The design includes a 17 dBm input and a 27 dBm output. The general worry is that with the lower frequency requirement that these dBm specs won't work in the testing stage. This is only the second amplifier I have designed so bare with me if I missed any crucial information on the datasheet.

[Peter BENSCH]

Welcome ​@ejfowler7, to the community!

The datasheet does not show a large-signal Class A characterisation at 55...59MHz. Its power-performance data are mainly at 480...520MHz and 860MHz; it does include small-signal S-parameter data from around 50MHz, but those data do not establish output power at your operating frequency.

Your targets correspond to approximately 50mW input and 0.5W output, or 10dB gain. This looks plausible as an initial design target, but the datasheet’s 3W, 17dB-gain result is at 500MHz and cannot be directly extrapolated to 55...59MHz. The matching network and Class A bias will need to be designed and verified at the target frequency.

Regards
/Peter