tony_lth
Advanced Member level 5
I meet a match problem.
A receiver has a diff line input, and it has a S1P (one port S parameters) file which based on 100 ohms.
And between the antenna and receiver is a un-balanced to balanced filter.
The impedance of the antenna and the unbalanced port of the filter is 50 ohms.
The impedance of the balanced port is 150 ohms.
I need to design the match circuits between the balanced port and the diff line input of the receiver.
My question is:
1. The impedance of the matching circuits should be normalized to 100 ohms, right?
2. Should I match to minimal NF, because it's a receiving system?
Although I can match with S-parameters, it is a minimal VSWR matching, not a minimal NF matching.
3. And how can I test with standard 50 ohms VNA systems? Such as VNA input and output cable, they are both 50 ohm. So I only can test at the un-balanced port of filter, right?
Thanks.
A receiver has a diff line input, and it has a S1P (one port S parameters) file which based on 100 ohms.
And between the antenna and receiver is a un-balanced to balanced filter.
The impedance of the antenna and the unbalanced port of the filter is 50 ohms.
The impedance of the balanced port is 150 ohms.
I need to design the match circuits between the balanced port and the diff line input of the receiver.
My question is:
1. The impedance of the matching circuits should be normalized to 100 ohms, right?
2. Should I match to minimal NF, because it's a receiving system?
Although I can match with S-parameters, it is a minimal VSWR matching, not a minimal NF matching.
3. And how can I test with standard 50 ohms VNA systems? Such as VNA input and output cable, they are both 50 ohm. So I only can test at the un-balanced port of filter, right?
Thanks.