Help me to establish delay line value in my FF amplifier design

Hi i work whit this schema of linealization for power amplifier... but i have a problem... in the schema are a delay line but this delay line what value have or how i can know the delay for this element.....thaks for u help

Re: FEEDFPRWARD SCHEMA

I will sugest to try to find Pothecarys book about feedforward Amplifiers, that will give u quite a lot of inforrmation about FF topology.

A FF Amplifier consits of 2 loops, 1st loop u have your main amplification unit.Input signal is splited at first loop and combined again (substracted) before the input of your Error amplifier. The signals at the input of your subtraction coupler should have the same delay. Tha means The DElay introduced by your main Amplifier Arm PLUS The delay of the vertical Coupled Path that goes inside to the Substractor should be mached with the Delay of your Delay line. The Value of your delay line depents on your main amplifier path, plus the couplers phaseshifters etc u use in your arms.

Exactly the same goes for the 2nd loop.

Look at the picture when i have modified yours a bit to show the paths

Re: FEEDFPRWARD SCHEMA

and wath about phase!!