Communication channel using logarithmic detector amplifier (LDA) demodulator

摘要

A method is provided for communicating signals at a low power level in an electromagnetic interference (EMI) environment. A first device transmits a modulated signal having a first carrier frequency, including the encoded information via a hardwire transmission medium. In one aspect, the power level of the modulated signal can be adjusted to minimize power consumption or reduce the generation of EMI. The modulated signal may be in one of the following formats: frequency modulation (FM) or phase modulation (PM) to name a few examples. A second device including a logarithmic detector amplifier (LDA) demodulator circuit receives the signal, which may be mixed with EMI. The LDA demodulator circuit amplifies the modulated signal, without amplifying the EMI, to supply a demodulated baseband signal, which may be an n-ary digital signal, or an audio signal. A low-power, noise insensitive communication channel is also provided.

主权项

1. A low-power, noise insensitive communication channel comprising:
a first device comprising:
a first modulator having an input to accept a baseband signal with encoded information, and an output to supply a modulated signal having a first carrier frequency including the encoded information;a first interface connected to a hardwire transmission medium to supply the modulated signal; a second device comprising:
a second interface connected to the hardline transmission medium;a first logarithmic detector amplifier (LDA) demodulator circuit comprising:
an amplifier having an input connected to the second interface, and an output;a feedback network connected between the amplifier input and output;a parallel resonant circuit connected between the amplifier output and a first reference voltage;a sampling circuit connected to the amplifier input, to supply an output signal including the baseband signal with the encoded information.