500 mW RF amplifier for 170 MHz design

Electrical Engineering Asked by betex on January 6, 2022

For a new project I need to build an RF amplifier for continuous-wave with about 500 mW (27dBm) output at 170 MHz.

It doesn’t need to transport data, it is only for measuring purpose.

The input comes from a signal generator, that can go up to about 15 dBm output, so the amplification needed is about 12 dB. The circuit should run with 5 V supply voltage.

The output of the RF amplifier is directly connected to an antenna, that is matched to 50 Ohm at 170 MHz.

A simple solution without big matching effort would be preferred, as I don’t have much RF measuring equipment, only a cheap chinese network analyzer (NanoVNA).

So far I tried some ADL5535, but always when the output comes up to 500mW (14Vpp) they got killed.

The same experience I had with a BFQ790. It was drawing about 500mA, when the output was OK, but then also died.
Heat dissipation should be no problem, as I’m using the PCB (with heat sink compound) of a former destroyed amplifier module for my experiments, see pictureenter image description here

I’d really appreciate some help, how to design a simple circuit, that is more robust against mismatching of the antenna. I know some theoretical basics about T or Pi-Networks, but I’d rather need some practical support.

Maybe someone has an example circuit (with components, that sill are active and available).

Add your own answers!

Related Questions

Reduce Noise Added With Zener Clipper

1  Asked on August 26, 2020 by oats


Ohms law’s statement

5  Asked on August 26, 2020 by ashaal-aalam


15V to 3.3V to power ESP12E

2  Asked on August 22, 2020 by muxa


How to attach a clincher connector to a FSR

1  Asked on August 9, 2020 by cerin


Understanding addressing and size in memory map

1  Asked on July 28, 2020 by kmc


Read 24 Vac signal with a Raspberry Pi

1  Asked on July 25, 2020 by riccardo-minati


Ask a Question

Get help from others!

© 2023 All rights reserved. Sites we Love: PCI Database, UKBizDB, Menu Kuliner, Sharing RPP