TRANSMISSION SYSTEM AND CONVENTIONAL VERY HIGH FREQUENCY OMNI-DIRECTIONAL RADIO RANGE TYPE RADIO NAVIGATION STATION WITH SAID SYSTEM

摘要

A generator (200) containing a clock (2) and a delay circuit (5), to provide a phase shift for the clock output, generates the sideband signals for a sample of a carrier (P). These signals are applied to a hybrid ring (7) which separates the upper (S1) and lower (S2) sideband signals. Frequency and phase comparators (11,12) allow the sideband signals to be compared with amplified (41,42) outputs of respective voltage controlled oscillators (31,32). This ensures that the upper and lower sideband signals are phase locked and do not contain the carrier or the other sideband frequencies. Low pass filters (21,22) remove harmonics of the modulating frequency. A second hybrid ring (13) recombines signals to provide the two sidebands (Bs,Bc).