What's the minimum distance of tracks carrying two IF signals?

[No one]

Hi everyone!
Suppose in a circuit there are two IF signal, for example 8MHz and 12MHz.
Should these two signal be shielded from each other? In PCB, what is the minimum distance of tracks carrying these two signal? Thanks.
No one

 

[biff44]

Re: Two IF signal

Depends on if there is a lot of IF gain (30 dB or greater?), and if the nature of the system is that one IF interfering with the other IF causing problems, like noticeable crosstalk, bit errors, or loss of signal tracking. Some types of processors do not care about leakage (direct sequence spread spectrum, processors with dsp filtering to knock out the unwanted frequencies, etc).

You can shield them by using two different metal boxes. You can get better isolation at IF by using differential components (diff amps, differential filters, etc). Leakage of one IF into the other's path will show up as common mode noise on the differential line, and the IF amps will reject that by 40+ dB.