3 ms·
> there won’t be any leakage of the LO that an enemy device could try to detect Why would an LO be more of an issue than your sample clock? edit: missing word
by elevation 3y ago
> there won’t be any leakage of the LO that an enemy device could try to detect
Why would an LO be more of an issue than your sample clock?
edit: missing word
- amluto 3y agoI don’t know all the details of this kind of technology, but I would imagine that one direct RF receiver’s sample clock looks effectively identical to any other similar receiver’s sample clock. So if these devices become popular, then a military sample clock is indistinguishable from a civilian sample clock. In contrast, an LO is rather application-specific.
- londons_explore 3y agoFor military use, where you are trying to blend in with civilian equipment, either the direct sampling clock, or the local oscillator frequency, could be randomly chosen in quite a wide range at bootup and still have the device work. In todays world with everything software reconfigurable, changing the sampling rate or local oscillator frequency is very do-able.
- AnarchismIsCool 3y agoIt's very hard to prevent the LO from leaking into the ADC input. Putting the filters in the right places would cause a lot of issues for the signal chain so a common workaround is trying to null it with a 180 degree out of phase LO signal.