Hughes Missile Systems Company

Raytheon Company

General Dynamics Corporation

General Dynamics Corp., Pomona Division

Garry N Hulderman

Richard J Swanson

Eugene Phillips

Allen C Hagelberg

Kenneth William Brown

Robert A Rosen

Kapriel V Krikorian

Ralston S Robertson

Frederick L Beckner

Thomas A Kennedy

Jay B Winderman

Darrell K Ingram

Hugh L Ord

Bernard W Drewes

A Cassegrain antenna system includes a flat dielectric plate radome having a thickness of one-half wavelength at a frequency of operation. The plate has an electrically conductive grid disposed on an inside surface thereof to permit perpendicularly polarized energy rays to pass there-through. A parabolic twist reflector is spaced from the radome, and includes a dielectric substrate having a thickness equivalent to one-quarter wavelength at a frequency of operation and having formed on an interior surface thereof an array of conductive strips oriented by 45 degrees relative to the incident ray polarization. A conductive ground layer is formed on an exterior surface of the substrate, wherein radiation reflected by the ground layer and passing through the dielectric substrate is shifted by 180 degrees in phase and is rotated in polarization when combined with energy reflected from the conductive strip array by 90 degrees relative to radiation incident on the twist reflector. The reflected energy from the polarization twist reflector is again reflected, this time by the grid formed on the radome surface, to a focal region. An RF housing with a plurality of RF feed elements is located at the focal region and are respectively spaced by a single beamwidth.

Electronically scanned cassegrain antenna with full aperture

An antenna system includes a beam source of a microwave wave beam, a gimbaled antenna, and a waveguide including a mirror system that directs the microwave wave beam from the beam source to the antenna. The mirror system is formed of a series of mirrors operable to reflect the microwave wave beam and includes a first paraboloid mirror positioned to receive the microwave wave beam from the beam source, a first planar mirror positioned to receive the microwave wave beam from the first paraboloid mirror, a second paraboloid mirror positioned to receive the microwave wave beam from the first planar mirror, and a second planar mirror lying on the system azimuth axis and positioned to receive the microwave wave beam from the second paraboloid mirror. The first planar mirror may be controllably tilted to finely steer the aim of the microwave wave beam to the antenna.

Magnified beam waveguide antenna system for low gain feeds

A covert and secure communication system which employs a very narrow bandwidth to permit receivers to be very sensitive to low power signals while maintaining acceptable signal-to-noise ratios. In the preferred embodiment, the system operates at the millimeter wavelength which, because of very high attenuation in atmosphere, will be undetectable beyond a very limited range. In another embodiment of the invention, the covert communication system is applied to an IFF system in conjunction with a homing missile. The IFF system of the present invention may be used as a back-up to confirm that a target is a foe by transmitting to and receiving a confirming signal from the target at the terminal portion of the engagement. For example, transmission between the target and missile may occur when the target and missile are less than 2,000 feet apart. The system is even less detectable and more secure because transmission only occurs during the very last portion of missile engagement which avoids the long range transmission of conventional IFF systems.

Missile shield

Methods that compensate for phase errors caused by path length variations in a radar system, and that compensate for relative phase errors in upconvertor and downconverter references employed in the radar system. One method samples a signal reflected from a duplexer through a receiver during the time the radar pulse is transmitted. The signal reflected from the duplexer is compared to a radar echo pulse on a single pulse basis. The phase of the sampled signal is subtracted from the phase of the received radar echo pulse reflected to determine the phase error. In a second method, multiple samples are collected during the time each radar pulse is transmitted. Samples of the signal reflected from the duplexer and the radar echo pulse are compared on a pulse to pulse basis. The phase differences are averaged across the pulse duration. The averaged phase differences are integrated on a pulse to pulse basis to determine the phase error.

Compensation for radar path length variation and phase error

Inexpensive and reliable apparatus for blanking the signal path between an antenna and a transmitter or a receiver to protect them from harmful radiation in the absence of power forms supplied thereto. The apparatus is preferably formed as a printed circuit waveguide switch window having a plurality of parallel conductors, such as metal wires or printed circuit traces, disposed on a dielectric substrate. The waveguide switch window is secured between two sections of waveguide. The conductors have a predetermined separation and width that are designed to appear as a solid metal surface that rejects radiation over a wide bandwidth. A bias terminal is coupled to the plurality of conductors, and insulating material is disposed between the bias terminal and the conductors to insulate the top portion of the grid array from the adjacent waveguide. The lower portion of the grid array is grounded to the adjacent waveguide. When the waveguide switch window is in its protective, blanked state, it blocks undesired radiation from entering the antenna and destroying sensitive components in the receiver. When a predetermined voltage is supplied to the bias terminal, it vaporizes the grid array and opens the waveguide switch window to allow normal operation of the antenna and receiver. As proven by tests, the waveguide switch window provides radiation immunity against high level input radiation power and high isolation (30 dB) for receiver protection in the blanked state, and with no measurable loss in the unblanked state.

Low cost, one-shot switch waveguide window

An array antenna (10) that can form and sweep a predicted radiation beam pattern in different directions by using a subharmonic frequency signal from each voltage controlled oscillator (VCO) (20) to control the array phasing. Each VCO (20) generates a radio frequency carrier signal that drives an antenna element (16). A subharmonic signal is generated from a portion of the signal from the VCO (20). The subharmonic signal is mixed with a constant frequency signal to produce an intermediate frequency (IF) signal. The frequency of the IF signal is compared to the frequency of a variable frequency signal in a phase locked loop (PLL) (40). Since the phase of a signal is dependent on its frequency, the variable frequency signal is generated to have a frequency corresponding to a certain phase. The PLL (40) generates an error signal as a function of the difference in frequencies between these two signals. In response to the error signal, the VCO (20) changes the frequency of the carrier output signal. This process is continued by PLL (40) until the frequency of the IF signal is equal to the frequency of the variable frequency signal. The VCO (20) is now generating a signal having a frequency corresponding to the certain phase. The combined resultant relative phase excitation of all the antenna elements generates a maximum field intensity in a predicted direction.

Spatial power combiner using subharmonic beam position control

A millimeter wave device having a dielectric substrate with a pair of substantially parallel planar surfaces with at least one predetermined millimeter wave circuit pattern formed in a conductive layer located on at least one of the substrate surfaces. A substantially planar conductive channel plate is mounted adjacent the conductive layer on one substrate surface with the channel plate having an aperture overlying each circuit pattern formed in the conductive layer. A substantially planar conductive cover plate is mounted adjacent one of the channel plates so as to form a first cavity in the region defined by the substrate surface, the channel plate aperture and the cover plate The device may further include a second substantially planar conductive channel plate mounted adjacent the other one of the substrate surfaces with the second channel plate having an aperture corresponding to and aligned with the first channel plate aperture. A second substantially planar conductive cover plate is mounted adjacent the second channel plate so as to form a second cavity in the region defined by the other substrate surface, the second channel plate aperture and the second cover plate. A substantially planar conductive back plate may be mounted adjacent each cover plate to provide support to the device structure. For the production at large quantity, high yield devices, the channel plates, cover plates, and back plates are fabricated by precision techniques such as by photolithography with chemical milling, or electrodischarge machine wire saw fabrication techniques to achieve device high performance operation. In an alternate embodiment of the invention the channel plates, cover plates and back plates are integrally formed for combining photolithography and electroforming techniques.

Millimeter wave device and method of making

A stepped beam transmit antenna that comprises a feed array that includes a dielectric substrate and a plurality of radiating elements disposed on the substrate. The radiating elements each comprise two coplanar and coextensive fins that are separated by a narrow gap and that are tapered at their radiating end to form a linear tapered slot feed aperture. Beam position inputs are disposed at respective input ends of each of the radiating elements. A backshort is disposed adjacent the tapered slot feed aperture of each of the radiating elements. A low pass filter is disposed adjacent the backshort of each of the radiating elements. A switching diode is disposed between the backshort and the tapered slot feed aperture of each of the radiating elements. The antenna includes a power distribution network comprising a suspended printed line. A lens is disposed adjacent the feed array for projecting energy beams produced by the antenna. A radar system is also disclosed that has a transmitter coupled to the transmit antenna, and a receive beam antenna that is coupled to a radar signal processor for processing radar return signals to produce a radar image.

Stepped beam active array antenna and radar system employing same

Apparatus and method for conveying information from an object by delayed reflection of an interrogating ultra-high range resolution radar signal which is digitized into a series of programmable spaced pulses by an electronic license plate circuit. The electronic license plate includes a plurality of unique programmable delay lines connected through a coupler network to an antenna.

Electronic license plate apparatus and method

A millimeter wave device having a dielectric substrate with a pair of substantially parallel planar surfaces with at least one predetermined millimeter wave circuit pattern formed in a conductive layer located on at least one of the substrate surfaces. A substantially planar conductive channel plate is mounted adjacent the conductive layer on one substrate surface with the channel plate having an aperture overlying each circuit pattern formed in the conductive layer. A substantially planar conductive cover plate is mounted adjacent one of the channel plates so as to form a first cavity in the region defined by the substrate surface, the channel plate aperture and the cover plate. The device may further include a second substantially planar conductive channel plate mounted adjacent the other one of the substrate surfaces with the second channel plate having an aperture corresponding to and aligned with the first channel plate aperture. A second substantially planar conductive cover plate is mounted adjacent the second channel plate so as to form a second cavity in the region defined by the other substrate surface, the second channel plate aperture and the second cover plate. A substantially planar conductive back plate may be mounted adjacent each cover plate to provide support to the device structure. For the production of large quantity, high yield devices, the channel plates, cover plates, and back plates are fabricated by precision techniques such as by photolithography with chemical milling, or electrodischarge machine wire saw fabrication techniques to achieve device high performance operation. In an alternate embodiment of the invention the channel plates, cover plates and back plates are integrally formed by combining photolithography and electroforming techniques.

A method for making a millimeter wave device having a dielectric substrate with a pair of substantially parallel planar surfaces with at least one predetermined millimeter wave circuit pattern formed in a conductive layer located on at least one of the substrate surfaces. A substantially planar conductive channel plate is mounted adjacent the conductive layer on one substrate surface with the channel plate having an aperture overlying each circuit pattern formed in the conductive layer. A substantially planar conductive cover plate is mounted adjacent one of the channel plates so as to form a first cavity in the region defined by the substrate surface, the channel plate aperture and the cover plate. The device may further include a second substantially planar conductive channel plate mounted adjacent the other one of the substrate surfaces with the second channel plate having an aperture corresponding to and aligned with the first channel plate aperture. A second substantially planar conductive cover plate is mounted adjacent the second channel plate so as to form a second cavity in the region defined by the other substrate surface, the second channel plate aperture and the second cover place. A substantially planar conductive back place may be mounted adjacent each cover plate to provide support to the device structure. For the production of large quantity, high yield devices, the channel places, cover plates, and back plates are fabricated by photolithography with chemical milling, to achieve device high performance operation. Alternatively the channel plates and back plates are integrally formed by combining photolithography and electroforming techniques.

Radar apparatus that includes a millimeter wave radar transmitter comprising a flood beam antenna, and a radar signal processor for processing radar return signals to produce radar output signals. An RF sensor comprising a receive antenna includes a plurality of antenna elements, a plurality of respectively coupled to outputs of the plurality of antenna elements and coupled to the transmitter by means of a coupler, a plurality of filter circuits respectively coupled to outputs of the plurality of mixers, a multiplexer coupled to outputs of the plurality of filter circuits that comprises as a multiple input, single output switch for sequentially outputting video signals derived from radar signals received by each of the receive antenna elements, and a lens for imaging radar returns onto each of the plurality of antenna elements. The heart of the present invention is a heterodyne receive antenna that may be used in many applications, including radiometric or radar applications, and the like. The present invention provides for a 35-300 GHz millimeter wave electronic scanning sensor for use in collision avoidance applications, and the like.

RF sensor and radar for automotive speed and collision avoidance

A system for controlling the arming and firing of a weapon that is suspended from a parachute at an oblique angle and spun so as to be aimed over a spiral rotational scanning pattern on the earth as the parachute descends toward the earth. The weapon is supported by a platform so that the weapon is aimed in a predetermined direction relative to the platform. A detection system is supported by the platform and aimed in the same direction as the weapon for detecting predetermined radiation characteristics from targets of opportunity. A ranging system is supported by the platform and aimed in the same direction as the weapon for determining the range to the earth in such direction. A first circuit is coupled to the ranging system for enabling the weapon to be armed in response to the ranging system determining that the range to the earth in the direction that the weapon is aimed is less than a first predetermined distance; and a second circuit is coupled to the detection system and the ranging system for enabling an armed weapon to be fired in response to either the detection system detecting the predetermined radiation characteristics or the ranging system determining that the range to the earth in the direction that the weapon is aimed is less than a second predetermined distance that is shorter than the first predetermined distance.

Target detection and fire control system for parachute-suspended weapon

An apparatus and method for generating an output signal having portions thereof being linearly swept in frequency. A controller, responsive to external signals, generates a series of control signals. An oscillator, responsive to each one of the control signals, produces an output signal. The output signal includes a series of output waveforms each linearly swept in frequency and corresponding to a respective one of the control signals. A first servo, responsive to each one of the output waveforms, produces a series of first correction signals each dependent upon the linearity error in a corresponding one of the output waveforms. The first correction signals modify a corresponding control signal as applied to the oscillator so as to correct linearity errors occurring in a corresponding one of the output waveforms. A second servo, responsive to each one of the first correction signals, produces a series of second correction signals each dependent upon the correlations in the first correction signals. Each one of the second correction signals modify a following control signal in the series of control signals as applied to the oscillator so as to correct the correlated linearity errors occurring in each one of the output waveforms.

Growing community of inventors

Riverside, CA, United States of America

Garry N Hulderman