I am trying to locate a manufacturer and part number for three RF parts in
some existing equipment (no docs available). The marking don't match
anything I can find from the usual suspects, and no one's marking schemes
seem similar. I'd appreciate if anyone can point me to the vendor.

The first is a GaAs SPDT RF switch in a 6 pin SOT, and is marked "31E". Its
pinout appears to be:
1 RF#1
2 Ground
3 RF#2
4 Control
5 RF Common
6 Ground

The other two are amplifiers, labeled "4CH" and "4CJ". They are also in 6
pin SOT package with pinouts of
1 Ground
2 Ground
3 RF In
4 DC in
5 n/c
6 RF out

Thanks,
Steve