GB1287239A - Amplifying device for single sideband signals - Google Patents

Abstract

1287239 Amplifiers; amplitude modulation THOMSON-CSF 28 May 1971 [30 June 1970] 18187/71 Headings H3R and H3T A device for amplifying single sideband signals comprises two channels fed in parallel by the input signal, and respectively feeding the highfrequency input and the modulation input of an amplitude modulator 4, Fig. 1. The first channel comprises limiting means 2 and amplifying means 3, while the second channel comprises an envelope detector 7, pulse modulating means 8 for delivering pulses the width of which is modulated by the envelope signal, an amplifier 9 operating so as to be always either blocked or saturated by the pulses, and an integrating device 9 for reconstituting the envelope signal. The amplifier 3 may also operate in switching mode, between blocked and saturated conditions. Amplitude modulator.-The modulator 4, Fig. 1, may comprise a pair of transistors 20, 21, Fig. 3, with their emitters earthed and the highfrequency signals fed in push-pull to their bases. The collectors are connected respectively to conductors 25, 26 which form balancedlines with conductors 29, 30, respectively, the lines being surrounded by ferrite blocks 36, 37 respectively. Conductors 25, 30 are connected together at their ends remote from the transistors, and to ground via capacitor 34, while conductors 29, 30 are connected together at their ends adjacent the transistors, to ground via capacitor 32 and also to terminal 6 to which the modulating signal is applied. Conductors 26, 29 are connected together at their ends remote from the transistors and to an output terminal 35.