Hello everybody,

I would like some advices on balanced matching circuit utilisation. Today, my goal has to use in series a MRF136Y and a D1008UK with a wide-band working (from 40 MHz to 400 MHz) but I obtain some problems of impedance between.

After the MRF136Y, I use a transformer to obtain an unbalanced 50 Ohms output and after, I use a guanella transformer to attack the D1008UK but I think that it exist an easier method that my method. But which ?



Secondly, I don't understand the input stage (balanced matching network ?) of the D1008UK application note shematic (cf picture), I'm looking for some explications.



Have a good day!

Joss

 

Edit : in output of mrf, i use a balanced* transformer.

 

Edit 2 : a 3:1 or 4:1 balanced* transformer, I confirm that information tomorrow.

 

I confirm that the transformer used in output of mrf is a 1:4 transformer.

 

Hello everybody,

I would like some advices on balanced matching circuit utilisation. Today, my goal has to use in series a MRF136Y and a D1008UK with a wide-band working (from 40 MHz to 400 MHz) but I obtain some problems of impedance between.

After the MRF136Y, I use a transformer to obtain an unbalanced 50 Ohms output and after, I use a guanella transformer to attack the D1008UK but I think that it exist an easier method that my method. But which ?

View attachment 164583



Secondly, I don't understand the input stage (balanced matching network ?) of the D1008UK application note shematic (cf picture), I'm looking for some explications.

View attachment 164584

Have a good day!

Joss

The 100 pF capacitors are just used as DC-blocking purpose. Only L1 is used for impedance matching.

 

Ok, thank you Cariban. I'm looking for method, to realize retro-engineering on L1, to know his utility and adapt his value for my application.