i have a SISO system with microwaves devices. The 16-QAM information is about 20KHz , upconverted at 30 MHz and then at 2462MHz.At the receiver the same procedure, downconverting. After the first LNA i have a BPF fc=2430MHz which has large Bandwidth so it does not protect me from interferense signals. It has 200MHz BW. Although, i have a BER about 10-4 maybe 10-5 if the channels is clear (more often at evening).I did this setup in a Laboratory and behind us there are a lot of with WiFis transmitting all day etc...
i did a purchase of Cavity Filters with center freq at 2462MHz and BW=25MHz. i replace the BPF with the cavity and........the result is worse!!! i have 10-3 maybe 10-4 BER Can you please tell me some ideas to fix this problem?