Doppler double sideband omnidirectional radio beacon - signal format is matched to precision-DVOR system

摘要

A central antenna transmits an amplitude-modulated first signal at frequency fo and two individual radiators transmit second and third signals at frequencies fo + f, and fo - f, cyclically in one sense of direction and fourth and fifth signals at frequencies fo + f2 and fo - f2 in the other sense, whereby the azimuth is obtained by a receiver from the phase difference of the demodulated signals, as in 2160731. The resultant of the fourth and fifth frequencies is transmitted in phase quadrature to the resultant of the second and third frequencies, and the fourth and fifth signals are demodulated together in the receiver. Although the signal format is matched to the precision-DVOR system, the geater precision of the beacon over the latter system is retained.