Hello all,

I was wondering if I could get some help. I am looking into designing some RF circuits for a project and I was wondering if there are any commonly used topologies for amplifing the signal? I found this pdf which I have been using as a reference:
http://www.qsl.net/v/va3iul/RF Power Amplifiers/RF_Power_Amplifiers.pdf

But the document presents all of the topologies that are available. Which is fine but again, I am wondering if there are any that are used alot in RF FM design.

Also, for one of my projects, I will be using RDS to control a device. Again, I was wondering if there are any commonly used amplifiers for FM sideband (the sideband is what the RDS works in).

 

I don't think there os a preferred topology. Depends on the needs and constrains of the circuit/application.

 

It all depends on what your details are. They might even have a chip for it.

 

Look so most common RF power stage.
Voltage divider of 2 capacitors and 1 coil. Minimum structure between two working common emitter bipolar transistors.
The structure (voltage divider of 2 capacitors and 1 coil) acts as a filter and and impedance adaptive.

Impedance adaptation should be done exit between the first stage outout and second stage input and so on.

How RF transistor parameters differ for the same type of transistor, there are many elements of this adjustment (variable capacitor).

Well filtered power for each stage.
RFC stops low frequencies, including constant current.

EDIT: I added a variation in witch voltage B-E it is performed using a diode.

 

Hello,

The shown schematic is a class C amplifier as there is no bias.
It can only be used for FM as AM and SSB will require a linear amplifier.

Bertus

 

Is why he has "multiple" output filters.