coolpixs4
Junior Member level 1
I have designed a diversity antenna distribution system for UHF broadband
My first design as Case 1 (attached picture)
Port 1 is comming from Antenna 1
Port 2 is comming from Antenna 2
It is a diversity antenna distributor system to multiple receivers.
If port 1 is fed by 10dBm RF signal the isolated P1-P2 is about 30 dB
The situation are:
- Firstly, the LNA is used is Berex BL022 (I though this LNA has its own prolem that's why The Berex now discontinued this IC and then release a new one with the new name BL022A)
- Previously, If port 1 is fed and port 2 is open then one of the IC become damaged (when using BL022) => The new team leader said due to the isolated between P1/P2 (case 1), so the signal from LNA1 going to output of the LNA2 (if port 2 open) then accumulated reflect => damaged. Is it true ?
- The same circuit in Case 1, after I changed the IC to BL022A, and did not observe any damaged
Now, the new team leader who comming this year in our team, he asked me to modiffy the circuit to the Case 2 (attached picture)
- Removed LNA 1, LNA 2 and using only a single LNA as depicted in Case 2 (this is a temporary modding for test)
- Case 2, The isolated property from P1-P2 drop to about 13dB
In my opinion, if we modify the circuit as Case 2, we will loosing the diversity of the two antenna.
Please, give me any comments or advice.
Which one is correct Case 1 or Case 2 ?
Thank you.