Abstract: An antenna including a lens that has an array of radiating elements located on a focal arc, each radiating element corresponding to a different transmission beam direction; and a beam launcher having a plurality of phased arrays and a plurality of internal probes, each of the plurality of internal probes being electrically coupled to a corresponding one of the radiating elements, the phased arrays for space feeding a selected one or more of the radiating elements with signals so as to generate corresponding transmission beams from the lens.

Abstract: A multipurpose system provides radar surveillance for air traffic control purposes. The system includes four separate active phased-array antennas, each with .+-.45.degree. coverage in azimuth, from 0.degree. to 60.degree. in elevation. Each antenna element of each phased-array antenna is coupled by a low-loss path to the solid-state amplifier associated with a transmit-receive (TR) module. Each antenna produces a sequence of pencil beams, which requires less transmitted power from the TR modules than a fan beam, but requires more time because the pencil beam must be sequenced to cover the same volume as the fan beam. In order to scan the volume in a short time, the PRF is responsive to the elevation angle of the beam, so higher elevation angles use a higher PRF. Low elevation angle beams receive long transmitter pulses for high power, and pulse compression is used to restore range resolution, but the long pulse results in a large minimum range within which targets cannot be detected.

Abstract: An antenna system provided with an adjustable reflection coefficient includes at least one radiation source (1), a reflective surface (12) positioned in the path of the radiation generated by the active radiation source (1) and 9 light-generating means (13, 14). The reflective surface (12) is provided with semiconductor surfaces (2.i.j) with a spacer-therebetween and the light of the light-generating means (13, 14) is used to illuminate the semiconductor surfaces (2.i.j) such that, after reflection of the radiation generated by the active radiation source at the reflecting semiconductor surfaces, a radiation beam is obtained in which the beam width and beam orientation can be varied by adjusting the light intensity so as to adjust the phase of the reflection of the semiconductor surfaces.

Abstract: An array antenna for a radar is shown in include a phase shifter arrangement wherein, in the transmitting mode, ferrite phase shifters are used to collimate and direct a beam of transmitted radio frequency energy originating at a feed horn and, in the receiving mode, amplifiers and diode phase shifters are used to amplify and to focus received radio frequency energy on a feed horn.

Abstract: An interferometric acoustooptic signal processor utilizing a circular antenna array to cover a 360 degree field of view. Each antenna element of the array is connected to an input port of a Butler matrix. The signals are phase shifted within the Butler matrix and applied to a multi-channel periodic Bragg cell, resulting in generation of one or more acoustic waves therein. A laser beam is used to illuminate the Bragg cell and is modulated due to interaction with the acoustic waves, resulting in diffraction of the laser beam and generation of a diffracted beam pattern output from the Bragg cell. A Fourier transform lens focuses the diffracted laser beam on a back focal plane at a point characterized by two perpendicular coordinates designating the input signal power spectrum and the angle of incidence in relation to the antennae, respectively.

Abstract: A wideband, true time delay antenna beamforming network 10 for millimeter wave phased array antennas is disclosed herein. The beamforming network 10 of the present invention includes a laser 30 for generating a beam B of electromagnetic energy. The beamforming network 10 further includes an electro-optic modulator 40 for modulating the beam B in response to an input signal S modulated about a first frequency f.sub.o. A first antenna array 80 generates a first electromagnetic field pattern P by radiating the modulated beam B' in a first direction. The present invention further includes a constrained lens 90 for receiving the first field pattern P and for emitting an antenna driver feed beam F in a second direction in response thereto. An antenna array driver 115 electro-magnetically coupled to the constrained lens 90 by the feed beam F provides a set of signals modulated about the first frequency f.sub.o to drive an antenna array 20.

Abstract: A signal processor for radar systems having phased array antenna structures. The processor determines the angle of arrival of the signal from a discrete energy source. The separate elements or output ports of the antenna structure are sampled to form a matrix of signal values. These values are converted into polynomial expressions consistent with one of the spectral estimating methods of maximum entropy, maximum likelihood, and thermal noise. The roots of the polynomial expressions are found and compared to the distance of the unit circle in a pole-zero diagram. Roots sufficiently close to the unit circle are selected as representative of the source signal peaks and the angular directions to such sources are determined by the corresponding angular location of the selected roots in the pole-zero diagram.

Abstract: An optical limited scan antenna system is disclosed. The invention is a dual lens type array antenna system with a small array feed network. The system includes a bootlace-type microwave aperture lens with an array of radiating elements arranged along the linear aperture and an array of pickup elements arranged along the curved inner surface, an intermediate optical corrective lens, a feed array for illuminating the corrective lens with a source distribution, and with a power divider and phase shifters arranged to drive the feed array. The corrective lens is circularly symmetric (spherically symmetric in the three-dimensional case), and its radially varying dielectric constant is such that a point source on its surface is focused to an image point on the inner surface. The pickup elements on the curved surface of the aperture lens are coupled to corresponding radiating elements on the linear aperture.

Abstract: A shipboard search radar in which an antenna beam is stepped up and down in elevation to keep the beam pointed approximately toward the horizon even though the ship may be rolling and/or pitching.

Abstract: An agile beam control for optical phased array wherein a great multiplicity of substantially identical wave guides are employed, each of which comprises a plurality of electrodes along the length thereof, and wherein electrical voltages are applied to such electrodes in a predetermined pattern so as to effect the necessary control without creating a totally unworkable arrangement of different voltages and wiring arrangements which are intolerable. More specifically, a binary voltage distribution is provided to such electrodes, whereby alternate ones of the electrodes in a first electrode position of such wave guides are interconnected and have a given voltage applied thereto. The remaining electrodes at that position are energized with the same magnitude of voltage but of reverse polarity.

Abstract: The present invention relates to a high-power solid state amplifier arrangement comprising a large number of solid state amplifiers disposed in a waveguide array. The waveguide array is disposed in the aperture of an antenna feed arrangement at the image plane of an antenna feed to receive a uniform distribution over the array with substantially no spillover. Each of the large number of parallel waveguide sections of the array includes one or more solid state amplifiers in a serial, waveguide-interconnected, arrangement, and a wideband impedance matching arrangement in the waveguide configuration at the input and output of the section.

Abstract: A mechanically positioned phase steered transfer lens which is illuminated y a fixed collimation lens. Wide angle scan is accomplished by tilting the movable lens and electronically scanning the beam to the desired angle. The mechanical motion minimizes the required electronic scan angles, thus minimizing the number of phase shifters required.

Abstract: A system for an electronically controlled array for the simulation of passive signatures and noise at millimeter wavelengths. The system can simulate passive background signatures and also superimpose radiation intensity variation to simulate either moving or stationary passive signatures of targets over or within the background. A single, non-varying source of millimeter waves provides the non-coherent radiation for illumination that is required for simulating passive signatures. A controlled array variably controls radiation intensity at each illumination point of the array. The non-varying source is concentrated at the focal axis of a parabolic reflector, providing a plane wavefront of radiated energy.