Electronically Scanned Arrays for Fast Testing of Large Antennas
ABSTRACT: The use of probe arrays is a well-established technology for spherical near field systems offering all the possibilities and accuracies of traditional single probe testing at a much faster speed [1-4]. Frequency ranges for probe arrays are from 75 MHz to 18 GHz. Recently, the problem of exhaustive testing of the high number of multi beam antennas integrated on future satellite systems has received considerable attention. Based on conventional measurements techniques, this testing would lead to unacceptable cost and duration. Solutions based on “hybrid technology” that take full advantage of fast probe array technology on large mechanical scanners can drastically reduce the measurement time as compared to conventional single-probe test systems. The single probe systems are still necessary to measure antennas at higher frequencies. Hence, a dual technology system, combining single probes and multi-probes, has been investigated. In this set-up, the tower positioner of the probe array can rotate 180 degrees to switch easily from the multi-probe set-up (0.5 - 18 GHz) to the single-probe set-up (0.5 - 110 GHz). The single-probe positioner is also used as a calibration arm for the probe array, allowing maximum dual-use of the equipment. This paper discusses the testing of a dual technology T-planar near-field system at Intespace in Toulouse.
The measurement needs of today’s space industry have evolved drastically. Payload complexity and size has increased and implementation of up to 8-12 antennas on a single platform is no longer uncommon. The future need for multi-beam antennas in Ku and Ka bands for multimedia, telecom and military applications with a high number of beams (20 to 100) including full system performance parameters such as pattern, C/I etc., further adds to the complexity of the testing.