I want to use RF 6886 power amplifier for VHF band design. The datasheet doesn't mention VHF design specifications. Has anyone used the PA for VHF design? If yes then please share your designs.
The datasheet doesn't mention VHF design specifications.
VHF is 30-300 MHz. The Chip is only specified for 100 MHz upwards – so the lower part of VHF will definitely work very suboptimally.
So my first reaction would be: you're trying to use the wrong amplifier for VHF.
Anyway, assuming you're just considering the 100 – 300 MHz range: As far as I can read the data sheet, I'd say they expect a designer to have access to a network analyzer; the numbers they give for nominal complex input impedance for 430 MHz indicate that if you can design a 100 MHz - 300 MHz line with 50 Ohm impedance, then you should be fine :)
So, the main problem here is that you're in charge of designing a matching circuit, and that for a very wide band (100 - 300 MHz is as much bandwidth than the center frequency of 200 MHz! This means you need a wideband matching circuit). That won't be trivial. To be honest, you should ask their sales people for S-parameters at 100 – 300 MHz if this is your region of interest.
Generally, if you don't have access to calibrated microwave network analyzers, I'd simply estimate a matching inductance value from their 900 and 430 MHz examples, and try with their eval board; not like that you could get perfect matching with a single component over the whole 100-300 MHz band, anyways.