Method of and system for tracking an object radiating a circularly or linearly polarized electromagnetic signal

摘要

To track an object such as a space probe or a satellite emitting an electromagnetic radio signal, the signal received at a ground antenna is passed through a circular waveguide section propagating modes TE11 and TE21. Polarized signal components of the higher TE21 mode are extracted from the waveguide through two pairs of lateral slots and their differences are multiplied by an r-f reference signal of the same frequency obtained from a preamplifier coupled to an output port to which the signal of mode TE11 is transmitted by way of a rotatable polarization changer. Corrective signals resulting from these multiplications are proportional to spatial coordinates of the tracked object in a predetermined Cartesian system, one of whose axes coincides with that of the waveguide section, and serve to keep the antenna trained upon the object. The polarization changer is rotated until the signal power available at the output port is a maximum, a corresponding rotation being imparted in the case of a linearly polarized radio signal to the circular waveguide section.