Accession Number:

ADA409030

Title:

Space Fed Subarray Synthesis Using Displaced Feed Location

Descriptive Note:

Corporate Author:

AIR FORCE RESEARCH LAB HANSCOM AFB MA SENSORS DIRECTORATE

Personal Author(s):

Report Date:

2002-01-15

Pagination or Media Count:

4.0

Abstract:

Wideband space-fed subarray systems are often proposed for large airborne or spaceborne scanning array applications. These systems allow the introduction of time delay devices at the subarray input terminals while using phase shifters in the array face. This can sometimes reduce the number of time delayed controls by an order of magnitude or more. The implementation of this technology has been slowed because the feed network, usually a Rotman Lens or Butler Matrix, is bulky, heavy and often has significant RF loss. In addition, the large lens aperture is necessarily filled with phase shifters, and so it introduces further loss, weight, and perhaps unacceptable phase shifter control power. These systems are currently viewed with increased interest because combination of low loss, low power MEMS phase shifters in the main aperture and solid state TR modules in the feed might lead to large scanning arrays with much higher efficiency then previously realizable. Unfortunately, the conventional system design imposes an extremely large dynamic range requirement when used in the transmit mode, and requires very high output power from the TR modules. This paper presents one possible solution to this problem using a modified feed geometry.

Subject Categories:

  • Radiofrequency Wave Propagation
  • Telemetry

Distribution Statement:

APPROVED FOR PUBLIC RELEASE