Method for tuning a phased array antenna
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 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.
- Publication:
-
Air Force Interim Report
- Pub Date:
- May 1985
- Bibcode:
- 1985aifo.reptU....G
- Keywords:
-
- Antenna Arrays;
- Phase Shift;
- Phased Arrays;
- Transmission Lines;
- Errors;
- Patents;
- Tuning;
- Communications and Radar