| 摘要 |
<p>1,075,017. FM/AM converters. COMPAGNIE FRANCAISE DE TELEVISION. Nov. 30, 1964 [Dec. 3, 1963], No. 48650/64. Headings H3A and H3R. In an FM/AM converter producing a balanced amplitude modulated output an FM input is applied through a delay device 22 producing a delay S equal to an integral number N of half cycles of the mean FM frequency to an adder device 26 if N is odd, or a subtractor device 26 if N is even, together with an undelayed input. Also the FM input is delayed by S/2 in a device 23 and after frequency conversion in a mixer 30 by a frequency input w 1 applied to a mixer 33 receiving also the output of adder (or subtractor) 26. The final output is shown mathematically to be a balanced amplitude-modulated wave of frequency W 1 (without carrier) whose amplitude varies proportionally with the input frequency deviation. The mixers 30, 33 may respectively be an additive and a subtractive frequency converter. The mixer 30 may alternatively be inserted between units 26 and 33.</p> |
