Transformer Coupling – Why Transformer Coupling Is Used in Simple Slope Detectors

So I've done some research since I have a similar problem and everything leads me to fully integrated quadrature demodulators like LT5517 with a good NCO if you need AFC. All digital systems with direct sampling might have even better noise performance especially if you use oversampling (source) but they have a detection delay, so your application should tolerate this delay if you want to use this method. Search for FPGA or DSP FM demodulators, there are plenty of articles. The best solution for data transmission I've found so far are specialized transceivers with interference resistance like AD9364, but those come in 144-LFBGA and cost $210 per chip. See this article for more info.

If you need a simple and decent demodulator, conventional quadrature demodulator has the best noise performance if you use high quality parts for it.

Here is an extract from the LT5534's data sheet. Note the part enclosed in a red box: -

What that line is saying is that the input power range is -63dBm to -2dBm i.e. a range of 61dB as indicated in the line below.

If you are still confused then 0(zero)dBm is 1 milli watt and if the circuit impedance is 50 ohm this means: -

\$\sqrt{P R}\$ volts or \$\sqrt{1\times 10^{-3}\times 50}\$ volts = 223.6mV RMS.

If you are still confused -63dBm is a power level of 501.2 pico watts and -2dBm is a power of 631 micro watts. I think you should be able to convert these to voltages by now.