Transmitter for a navigation system

摘要

In navigation transmitters it is important that the phase difference between the carrier waves of a carrier signal and the carrier waves of sideband signals be held at a constant value. To accomplish this, the carrier waves are maintained constant relative to a reference signal in a known manner. A phase meter measures the phase difference between the carrier waves of the sideband signals and the reference signal and between the carrier waves of the carrier signal and the reference signal. The measure values are used to determine the phase difference between the carrier signal and sideband signals which are compared with a desired value. Depending on the deviation from the desired value, a controllable phase shifter controls the phase of the carrier waves of the sideband signals. Since the measurements are made on a time-division multiplex basis, little circuitry is required. Any measuring errors do not affect the formation of the desired phase difference.