Epp, Inc.

United States of America As Represented by the Secretary of the Air Force

Bell + Howell Company

Roger E Clapp

Donald J Lennon

Richard L Smith

George William Ruggiero

Justin Melvin James, Jr

Multibeam lens antennas are often circular, and utilize propagation in disk-shaped parallel-surface regions. There is phase correction through terms in .theta..sup.2, where .theta. is the angle of an aperture point measured from the boresight direction. In the new designs herein, the lens comprises two portions, each being two closely spaced plates with a dielectric medium between them. One portion is formed as a surface of revolution (cylindrical or conical) with two circular ends, one end being an aperture with element feedpoints coupled to array elements. The other portion is a cap joined to the other end of the first portion. The cap may be a disk or a segment of a sphere. The dimensions and indices of refraction are selected to provide focus points for feed ports, with each focus being for a specific beam direction. The parameters may be selected so that the focus points are within the cap, at the periphery of the cap, or at the aperture. Some of the new designs have phase correction through .theta..sup.2 and .theta..sup.4, while others have phase correction through .theta..sup.2, .theta..sup.4, and .theta..sup. 6.

Multibeam lens antennas

Multiple beam antennas are modified and improved through the use of lenses coupled together by hybrid junctions. A dual lens structure avoids circulators while permitting the lenses to be used both for transmission and for reception. A six lens structure provides perfect phase focusing utilizing an R-2R geometry with a Mobius topology, giving 360 degrees of independent antenna beams from a single circular or cylindrical antenna array.

Radio frequency lens antenna

Structures for supporting printing articles in spaced aggregates as mounds and towers, for use in pulsed electrical printers, and method for their production. The structures comprise a base sheet having a roughened or microcavernous surface to receive the printing particles. The base sheet may be formed of or coated with conductive material, and may comprise a magnetizable material useful in forming and retaining the aggregates.

Structured donor sheet for high-resolution non-impact printer

Structures for supporting printing particles in spaced aggregates as mounds and towers, for use in pulsed electrical printers, and method for their production. The structures comprise a base sheet having a roughened or microcavernous surface to receive the printing particles. The base sheet may be formed of or coated with conductive material, and may comprise a magnetizable material useful in forming and retaining the aggregates.

A non-impact printer having a support for magnetic ink particles loosely distributed on its surface in mutually spaced aggregates of irregular height. An electrical field of short duration, established in a print position between the particles and a shaped print electrode, charges the particles and attracts them to an intervening recipient sheet. The printed image is rendered more uniform by magnetic reorientation of the aggregates of greater height before printing, in a field having components normal to the electrical field in the region of the print position.

Non-impact printer with magnetic ink reorientation

A personal paging device is housed in a case which has one dimension (length) longer than its width or thickness, and a clip is affixed to a side on a swivel between the ends of the length dimension, which allows the device to be worn on the person in a vertical or a horizontal posture. A radio receiving antenna is carried on a flexible dielectric sheet within the casing, and radio components are enclosed within that sheet. A pair of orthogonally-related antenna loops can be provided on the dielectric sheet. The swivel clip can be arranged to cooperate with these or other antennas in a circular-polarization antenna system, such that in one orientation one or the other of the antennas will be detuned.

Growing community of inventors

Cambridge, MA, United States of America

Roger E Clapp