Single-sideband suppressed carrier signal generator

Claim 1

APPARATUS FOR MODULATING A CARRIER SIGNAL WITH AN AUDIO SIGNAL TO PRODUCE A SINGLE SIDEBAND SUPPRESSED CARRIER OUTPUT, COMPRISING MEANS FOR PROVIDING FIRST AND SECOND CARRIER SIGNALS IN PHASE QUADRATURE WITH EACH OTHER, AN AUDIO SIGNAL SOURCE, A FIRST BALANCED MODULATOR, A SECOND BALANCED MODULATOR, SAID FIRST BALANCED MODULATOR BEING CONNECTED TO SAIDF AUDIO SIGNAL SOURCE AND TO SAID MEANS, THEREBY TO MIX SAID FIRST CARRIER SIGNAL WITH SAID AUDIO SIGNAL, SAID SECOND BALANCED MODULATOR BEING CONNECTED TO SAID SOURCE OF AUDIO SIGNAL AND ALSO TO SAID MEANS, THEREBY TO MIX SAID SECOND CARRIER SIGNAL WITH SAID AUDIO SIGNAL, MEANS CONNECTED TO THE OUTPUT OF SAID FIRST BALANCED MODULATOR, SAID OUTPUT EXHIBITING A SIGNAL COMPRISING A SUPPRESSED CARRIER FREQUENCY AND TWO SIDEBANDS, SAID SECOND-MENTIONED MEANS SHIFTING THE PHASE OF ONE SIDEBAND BY +90* AND THE OTHER SIDEBAND BY -90*, AND COMBINING MEANS HAVING INPUTS CONNECTED TO THE OUTPUTS OF THE SECOND MENTIONED MEANS AND THE SECOND BALANCED MODULATOR FOR ADDING SIGNALS PRESENT AT SUCH INPUTS TO PRODUCE A SINGLE SIDEBAND SUPPRESSED CARRIER OUTPUT.