A Receiver for Measuring Angle-of-Arrival in a Complex Wave

Since November, 1945, the Electrical Engineering Research Laboratory of the University of Texas has been engaged in making propagation measurements of 3.2-cm waves. Results of some of these tests have been published, but a description of the equipment used has not been generally available. This paper describes the latest arrangement of the phase-difference receivers, modifications of which were used in the tests previously described. This receiver provides data for separating two waves received simultaneously by means of signal-strength and phase-difference data received at three points. It is possible to measure phase difference between two 3.2-cm signals to an accuracy of 5° over a signal-strength range of 70 db and a signal-strength ratio between channels as high as 20 db. Absolute signal strength is measured to within 1 db, while relative signal strength is measured to 0.5 db.