Transmit two signals over an amplitude modulated carrier wave
This invention relates to amplitude modulation used in electronic communication devices. Existing methods modulate the amplitude of a carrier signal with respect to a modulating signal. In conventional AM, both positive and negative sides of the carrier wave carry the same signal. In this invention, the positive and negative halves carry different signals.
Invention (What is New)
The method modulates one signal on the positive side of the carrier wave and another on the negative side. This allows transmission of two different signals simultaneously on a single AM carrier.
A diagram shows: – (1) Carrier generator. – Signal modulated with sine wave (5) on one side. – Block (3) modulates the other side with a square wave. The final signal (36) has the top amplitude modulated with a square wave and the bottom with a sine wave.
Demodulation
A receiver uses two demodulators to retrieve both signals transmitted on one carrier. The outputs are shown as 48 and 54, the two separate signals carried on the same AM wave.