Help with 20dB Directional Coupler details

Hello,

Please see the attached directional coupler circuit.

I am trying to build a directional coupler to isolate 20 dB from 30 dBm input power of 50 ohm system.

The input power is 30 dBm and I want to match 2.2 GHz , 2.3 GHz and 2.4 GHz frequency bands.

- What should be the thickness of the main line if i want to use FR4 or Rogers boards?.
- What should be the thickness of the second line too ?.
- How long should the second line be in mm ?
- What should be the distance (spacing) between the 2 lines ?.
- What is the insertion loss of main line if we want to isolate 20dB ?

Thank you so much for your kind help


Regards,
Ghassan

"RF and Microwave Coupled-Line Circuits" Rajesh Mongia,Inder Bahl,Prakash Bhartia.Artech House

Sorry but I didnt understand!