Low-power receiver for FSK back-channel embedded in 5.8GHz Wi-Fi OFDM packets

A low power RF receiver, comprising:

• an analog front-end circuit configured to receive an RF input signal and operates to down convert the RF input signal to a down converted signal, where the RF input signal is encoded with a binary frequency-shift keying method;
• and
• an intermediate frequency stage circuit configured to receive the down converted signal from the analog front-end circuit and route the down converted signal into two circuit detection paths, each circuit detection path further down converts the down converted signal into a baseband signal and thereby forms a pair of baseband signals;
• a first circuit detection path having a first mixer in series with a first low pass filter, wherein first mixer mixes the down converted signal with a first mixing signal to yield a first mixed signal, the first mixing signal having a frequency equal to a mark frequency of the binary frequency-shift keying method;
• a second circuit detection path having a second mixer in series with a second low pass filter, wherein second mixer mixes the down converted signal with a second mixing signal to yield a second mixed signal, the second mixing signal has a frequency equal to a space frequency of the binary frequency-shift keying method;
• wherein cutoff of the first low pass filter and cutoff of the second low pass filter are set in between zero and the space frequency of the binary frequency-shift keying method.