公开(公告)号：US3634766A

公开(公告)日：1972-01-11

申请号：US3634766D

申请日：1969-03-19

Applicant: CIT ALCATEL

Inventor： BOYER MARCEL LOUIS

IPC: H03J7/06 ,  H03L7/14 ,  H04B1/30 ,  H04B1/68 ,  H04B1/10

CPC classification number: H03J7/06 ,  H03L7/14 ,  H04B1/302 ,  H04B1/68

Abstract: A single or independent sideband radio transmitter having a high-frequency section for transmitting a high-frequency signal modulated by a low-frequency bandwidth and which is connected to receive the lower bandwidth section from a speech circuit and the upper bandwidth section from circuitry providing two lateral bands of equal width and equispaced from a reference frequency provided by an oscillator, the generation of the lateral bands being controlled by the speech level, and a radio receiver having separator filters connected to isolate respective subbands of equal width from an upper section of a received frequency spectrum containing speech modulation components, modulating and filtering circuitry provided with a fixed-frequency local oscillator and deriving from the subbands and the oscillator output a signal having a frequency which is significant of the carrier frequency as modified by an uncontrollable frequency deviation. a demodulator fed by a variable-frequency oscillator and by the lower section of the signal frequency spectrum, and a system controlling the operating frequency of the variable oscillator in accordance with the output of a discriminator which compares the variable oscillator output frequency with said signal from said modulating and filtering circuitry.