I've got this 3GHz RF amplifier off ebay, and I'm trying to figure out how it works. I've took the RF shield off, but the markings on the component that I assume is the transistor, are scratched off.

What transistor could have been used here?

Also, how can this thing work with just one transistor?

Here is a photo of my device:

enter image description here

The underside of the PCB is just a ground pour

  • \$\begingroup\$ What makes you think it is a single transistor? More likely at least two (or more) plus biasing resistors. \$\endgroup\$
    – glen_geek
    Mar 29, 2022 at 20:20
  • \$\begingroup\$ @glen_geek I've seen photos of similar devices, which had two of these components. And since I found lots of schematics for RF amplifiers with two transistors, I assumed these were the transistors \$\endgroup\$
    – Twometer
    Mar 29, 2022 at 21:37

1 Answer 1


The schematic of the circuit is as follows:


simulate this circuit – Schematic created using CircuitLab

U1 appears to be an integrated RF amplifier, not a transistor. I imagine that any transistor in an amplifier like this would require a DC path on all 3 of its terminals, whereas pin P1 is open at DC, so a transistor would work very poorly and wouldn't really amplify much.


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