SHORT RANGE INDUCTIVELY COUPLED COMMUNICATION SYSTEM EMPLOYING TIME VARIANT MODULATION

摘要

A short range magnetically coupled wireless communication system employs time variant modulation of a high repetition rate pulse stream and magnetic coupling between a transmission magnetic element and a receiving magnetic element. The pulse stream is modulated by an input audio frequency signal in the time domain, for example, through pulse position modulation, pulse width modulation or pulse symmetry modulation. The receiving magnetic element is coupled to a demodulator circuit which detects the transmitted pulses induced in the receiving magnetic element and reproduces the audio frequency signal. Transmission over short range is thus efficiently accomplished through magnetic coupling in a simple, low cost, low power consumption communication system.