Electronically Reconfigurable Microwave Lens Antennas

Abstract

The purpose of this report is to present the results of further investigations into the operation and design of two-dimensional Luneburg Lenses at 24 GHz, with the possibility for electronic control of their behavior. Various lens design techniques are illustrated; these include a holey dielectric lens (drilled dielectric) and, a holey plate lens (etched holes on the upper metal plate). Ray tracing theory is presented which shows the general properties of the gradient index lens. These results indicate that it may be possible to synthesize a tuneable lens whose focal length and /or radiation pattern can be adjusted by electronic modification of the lens dielectric properties. In addition a uniform outer layer lens and a two-shell lens are also demonstrated. Some preliminary investigations are presented with regard to the general properties of Liquid Crystal materials for tuneable lens use. Also we present preliminary design work on a MMIC reflection amplifier for ultimate deployment in active planar lens reflector for RCS enhancement. 1 Report Documentation Page Form Approved OMB No. 0704-0188Public reporting burden for the collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing the collection of information. Send comments regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing this burden, to Washington Headquarters Services, Directorate for Information Operations and Reports, 1215 Jefferson Davis Highway, Suite 1204, Arlington VA 22202-4302. Respondents should be aware that notwithstanding any other provision of law, no person shall be subject to a penalty for failing to comply with a collection of information if it does not display a currently valid OMB control number.

Quasi-optical analysis of a double reflector microwave antenna system

“…The size of R R must necessarily take 4 R into account, for obvious reasons. By defining the reflector's coefficient (c R ) as (35) and by substituting (31) one arrives at…”

“…On the other hand, depending on the application, lenses can eventually be more advantageous [25,26] with dielectric lenses receiving a lot of attention [27,28], due to their simplicity. Fresnel zone plate lens [29,30] and electronically reconfigurable Luneburg lenses [31] are also worth interesting. Several studies make use of both reflectors and lenses [32,33].…”