Massachusetts Institute of Technology

Electronic Space Systems Corporation

Eugene C Ngai

Dennis Blejer

Richard J Cotillo

Luther E Rhoades

Reuven Shavit

Carlo J Mistretta

Paul A Theophelakes

Joseph B Sangiolo

An antenna element is provided having a stacked patch configuration and having tuning structures by which the antenna element can be tuned at two different frequencies of operation. A plurality of the antenna elements can be combined to provide an antenna array. The antenna array can be provided having one or more surface wave surface wave control structures that isolate respective ones of the antenna elements from other respective ones of the antenna elements. The antenna element and/or the antenna array can be provided having RF feeds that can generate any pre-determined polarization.

Tunable multi-band antenna array

A method and apparatus are provided performing near-field measurements on dish antenna, in particular large dish antenna, and for utilizing these measurements to realign dish panels. The antenna is tiltable about a pivot point on a mounting pedestal to any desired elevation angle. A substantially circular track is provided which is centered at and spaced a predetermined distance from the pivot point, the track preferably being adjustably mounted to a stiff circular arch. The antenna is rotatable in the azimuth direction, preferably by rotating the pedestal, and a scanning probe is provided which is mounted for control traversal on the circular track. The probe is utilized to perform near-field measurements on the antenna at selected azimuthal positions of the antenna and selected positions of the probe on the track. The probe may also be rotatable to at least two different polarizations. The movement are performed in small stepwise increments in a predetermined sequence and measurements are taken by utilizing an RF signal transmitted by the antenna or probe and received by the other. For panel realignment, the near-field measurements are transformed mathematically to far-field values which are in turn transformed mathematically to holographic pictures which provide an indication of panel misalignment. This indication is then used to realign appropriate panels and the process repeated until panel alignments are within acceptable limits.

M&A for performing near field measurements on a dish antenna and for

Growing community of inventors

Northboro, MA, United States of America

Eugene C Ngai