Citation
Abstract
This article describes a possible approach to phasing an uplink array using radio sources in the sky. The calibration approach requires that each antenna in the array has, in addition to normal transmit electronics, two single-pole, double-throw power switches in the path of the transmit signal just before the feed; (phase) calibrated room-temperature radio-frequency amplifiers and a mixer assembly having stable path delays with time; a directional coupler and a power load; and a cable for carrying baseband signals to a central place for making phase measurements between the baseband signals from various antennas. This approach allows quick calibration of uplink array phasing at any time using a radio source close to any target direction. It also requires the measuring of the optics path length for each antenna initially (or whenever any change is done in the optics part of an antenna) in one of several possible ways that are described briefly. This is needed for the transmit signals to coherently add at a target without requiring that the optics path lengths be the same on all the array antennas.
Details
- Volume
- 42-172
- Published
- February 15, 2008
- Pages
- 1–6
- File Size
- 89.7 KB