So I need to demodulate the FM signal from a sensor with highest SNR possible, at least 70-75 dB. IF is 10.7 MHz, max. deviation is 200 kHz but I can change those values if needed. Baseband signal frequency range is 60-5000 Hz. There is a space constraint: PCB should not be larger than 18x40 mm. It also would be nice if the circuit could be powered from a 3.3-5V source.

Quadrature detectors I find have SNR of <60 dB which is insufficient. The only solution I found is NJW2311V but I can't find it for sale. Maybe there are other options?

  • \$\begingroup\$ What are you asking? Right now, it reads like a "design this circuit for me" question, which is off-topic. \$\endgroup\$ – Hearth Feb 16 '19 at 17:28
  • \$\begingroup\$ @Hearth I'm asking about demodulator topologies and/or ICs that can do the job. \$\endgroup\$ – cyrtex Feb 16 '19 at 17:43
  • 1
    \$\begingroup\$ The SNR you can get out is foremost a function of the signal you put in; at room temperature, without absurd powers involved, 75 dB is um... hard. I think you should start with a more in-depth discussion of what you're building. \$\endgroup\$ – Marcus Müller Feb 16 '19 at 17:44
  • 1
    \$\begingroup\$ Since your baseband bandwidth is somewhat narrower than the usual FM receiver spec, you could gain some dB SNR here. Space constraint suggests a PLL demodulator. \$\endgroup\$ – glen_geek Feb 16 '19 at 18:21
  • 1
    \$\begingroup\$ You'll likely want to lookup FM demodulation with PLL \$\endgroup\$ – sstobbe Feb 16 '19 at 18:21

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Browse other questions tagged or ask your own question.