Accession Number : ADD011768

Title :   Method for Tuning a Phased Array Antenna.

Descriptive Note : Patent,

Corporate Author : DEPARTMENT OF THE AIR FORCE WASHINGTON DC

Personal Author(s) : Gray,R P , Jr

Report Date : 14 May 1985

Pagination or Media Count : 5

Abstract : During installation or maintenance of a phased array antenna system in which the transmission line to each element includes an adjustable phase shift device, it is required that the effective electrical lengths of the lines be adjusted to be equal, or alternatively that the phase errors be determined and stored as correction data for use during normal operation. One way of doing this is to phase modulate by + or - 90 deg the phase shift device of one element at a time, while applying a test signal to all elements. The signal is radiated by the array, received via a test antenna, and supplied to and envelope has different amplitudes at + 90 deg and - 90 deg of the modulation. The element is tuned by adjusting the length of its transmission line or the length of its transmission line or the adjustment of its phase shift device to obtain a null at the amplitude detector. In an improved technique, to reduce certain errors, sum tuning is used, in which the + or - 90 deg phase modulation is applied to all of the phase shift devices, except for that of the element being tuned.

Descriptors :   *PATENTS, *TUNING DEVICES, *PHASED ARRAYS, TRANSMISSION LINES, ERRORS, PHASE SHIFT, PHASE MODULATION

Subject Categories : Electrical and Electronic Equipment
      Telemetry

Distribution Statement : APPROVED FOR PUBLIC RELEASE