WIDE BAND RF POWER AMPILIFIER USING RD16HHF1

This RD16HHF1 pushpull amplifier specially designed for two band transceiver project.The circuit diagram is mentioned below.This amplifier uses pushpull configuration technique.

Advantages of pushpull amplifier

1.Low distortion.

2.High efficiency.

3.High power output.

FUNCTION:

Operating voltage of this wide band amplifier is 13.8volt dc

Each transistor is biased to draw 400ma without feeding input signal

In this pushpull amplifier two output devices operate in antiphase(ie180deg apart.)The two anti phase outputs are connectedto a load in a way that causes the signal outputs to be added.

This circuit consists of an (input 0-180deg) power splitter driving two identical devices in antiphaseand a (0-180deg) output power combiner adding the output of the two devices in the amplifier load. Splitting is done through the input coupling transformer T1. When Q1 is driven positive using the first half of its input signal the drain current of Q1 increases. At the same time Q2 is driven negative using the first half of its input signal and drain current of Q2 decreases.  Each transistor produces one half of an ac.

The transformer combines the two outputs to form full ac cycle. As a result an amplified version of input signal obtained in the transformer secondary.

Biasing in this circuit is given using the 5volt regulator through the resistor networks to the gate of the transistor.

REQUIRED POWER IS 5WATTS (AVERAGE), 10 WATTS PEP

TEST RESULTS:

4MHz - 16 watts average

7MHz - 14 watts  average

14MHz-12 watts average

    

TRANSFORMER DETAILS:

T1-4TURNS BIFILAR 26SWG ON 10MM TORROID

T2-3TURNS BIFILAR 26SWG ON 10MM TORROID

T3-3TURNS TRIFILAR ON 10MM TORROID

PRI- 20SWG

SEC-22SWG