Interferometric direction-finding method, and direction finder using the same

摘要

1. An interferometric direction finding method consisting in receiving, by the antennae of an antenna array, the radio transmission whose direction is to be measured, in combining in a hybrid quadrature coupler the signals issued by two of the antennae of the array, which are spaced at a distance d and arranged to form an interferometric base for a phase of the direction measurement, and in connecting alternately the outputs of the coupler to the input of a first receive channel during the two half-periods of the successive switching periods in order to generate a first amplitude modulated signal, whose modulation index is a function of the direction of radio transmission, characterized in that, in order to obtain a measurement of the direction independent of the adjustment parameters of the first receive channel and of the received signal itself, a second receive channel is connected alternately to that output of the coupler which is not connected to the first receive channel, in order to generate a second amplitude modulated signal, and that an error value G depending on the phase shift DELTA phi = (2 pi d/lambda) sin alpha is computed at each switching period using the energy values measured during each half-period within each of the receive channels, with lambda being the transmission wavelength and alpha the detected transmission angle related to the orthogonal direction of said base.