Abstract: Ingredients of loaded dielectric media are specified for the achievement of high absorption and/or high reflection of electromagnetic power over very broad frequency bands and with very low material mass requirements on the absorbing or reflecting agents. The loading consists of dilute distributions of small metallic particles specified in terms of their individual properties, namely electrical conductivity, permeability, size, shape, and their collective properties, i.e., number densities, metallic volume fractions. The required permittivities of sustaining dielectrics and the thicknesses or penetration depths for absorption or reflection of the loaded media are also specified. These particulate and supporting dielectric properties are scaled with respect to the electromagnetic wavelength or frequency bands for the achievement of the desired percentage power absorption and/or reflection (in nonoverlapping bands). The invention applies to all frequencies below visible optical.

Abstract: A radio frequency energy radar system having a transmitting antenna system for transmitting and directing CW radio frequency energy toward a target. A receiving antenna system, adjacent to the transmitting antenna system, receives portions of the transmitted CW radio frequency energy reflected by the target. The receiving antenna system including a plurality of antenna elements disposed along a path and arranged to provide an antenna pattern having a main lobe antenna pattern directed toward the target and adjacent side lobe antenna pattern. A septum is positioned between the transmitting antenna and the receiving antenna, for shielding unwanted portions of the transmitted CW radio frequency energy from passing directly from the transmitting antenna to the antenna elements of the receiving antenna The shielding means terminates along an edge positioned in a region forward of the antenna elements.

Abstract: A distance measuring system which may be used on a golf course in order for a golfer to accurately measure the distance between the present lie of his golf ball and the hole toward which he is currently advancing the golf ball. A master transceiver station is portably carried by the golfer to be disposed proximate the lie of his ball for measurement purposes, and a remote transceiver system is located in or on each hole's flag marker pole. The present system uses, as the basic measurement frequency, only the frequency of the remote carrier itself. Two separate and distinct phase measurements are made in rapid succession. The first measurement is made with the master RF carrier displaced above the remote carrier frequency by amount equal to the IF frequency, and the second measurement is made with the master carrier frequency displaced below the remote carrier frequency by the same amount.

Abstract: A remote radar phase calibrator that provides radar phase measurement and libration. A trihedral or dihedral reflector placed in the radars field of view provides an amplitude calibrated phase stable signal to the radar. Movement of the reflector head-on to the radar provides a phase angle measurement that varies as a function of the radars transmitted wavelength and the distance the reflector is moved.

Abstract: A wideband radar apparatus is provided having improved interference suppression characteristics. The known time versus bandwidth characteristic of the transmitted pulse is utilized to effect intermediate frequency bandwidth reduction in received swath echo signals. During the interpulse period, basebanded swath echo signals are then subjected to a series of adaptive interference suppressing updates. The adaptive weight vector produced during each of these updates is then applied to the same data used to generate the weights. Preferably, adaptive weight generation is performed in a systolic array according to a QR decomposition algorithm.

Abstract: A radar homing system in a guided missile for intercepting one of a group of targets, such as aircraft flying in formation. Offset circuitry places undesired Doppler target returns outside of the IF filter bandpass frequency of the system. The system is designed to take cognizance of the highest Doppler frequency derived from the targets.

Abstract: A radio frequency automatic identification system detects targets which include solid resonators resonating at several frequencies, attributing information to the frequencies at which the target resonates. Preferred resonators are quartz crystals, which may be made by a process of heating quartz to soften it and cutting crystals to approximate size and resonant frequency. Resonators produced by such a process are measured to determine their actual resonant frequency, and preferably the crystals are sorted into predetermined frequency windows in accordance with their measured resonant frequency. A set of resonators having frequencies corresponding to predetermined data is selected from the sorted groups of resonators and incorporated into a target. The preferred target is an ink-like material having a plurality of resonators disposed in a matrix which is radio frequency transparent at the frequency of interest.

Abstract: The present invention relates to a signal processing method for a radar system. The transmitted signal here includes a polyphase code that is optimized to the desired range/Doppler range and that is repeated periodically over time.

Abstract: A radar system mounted on a satellite is scanned to provide surveillance of large areas such as the oceans. The transmitter oscillator generates bursts in the frequency range from about 20-250 megacycles. A receiver detects signals reflected from objects in the target area. The receiver enhances the value of recurrent components of selected time interval portions of the received signals. In one embodiment the transmitter bursts are modulated in accordance with a predetermined modulation pattern. The system determines to what extent it corresponds to the predetermined modulation pattern and then enhances the value of the recurrent components of the received signals. The enhancement is of those recurrent components having relative phases which change by substantially uniform increments.

Abstract: The Doppler shift motion detector has an effective motion detection range which can be changed by changing the power level and thus without changing the motion detection circuitry. The Doppler shift motion detector also has a self test for the wave transmitter and receiver which can be carried out without requiring placing a moving object in the monitoring area. The Doppler shift signal generated when the power level is changed is used to check the detector for the self test and is ignored by the detector alarm output circuitry when the power level is changed. An anti-masking feature is also provided.

Abstract: A system for simulating a moving target, having an antenna that emits a steerable propagation pattern, a receiver and a target signal generator. Analog signals representing the azimuth position of the target and the azimuth position of the antenna propagation pattern are summed yielding analog azimuth position signals. The analog azimuth position signals are then converted to digital code. Analog signals representing the elevation position of the target and the elevation position of the propagation pattern are summed yielding analog elevation position signals. The analog elevation position signals are then converted to digital code. The azimuth position digital code and digital code representing the propagation pattern direction are input into a memory unit which outputs an azimuth attenuation digital code. The elevation position digital code and the propagation pattern direction digital code are likewise input into a memory to produce an elevation attenuation digital code.

Abstract: A radar system is capable of detecting and classifying rotating targets such as rotating antennas. Particularly, unfriendly radar installations can be detected and classified by a synthetic aperture radar system, which may be carried by an aircraft.The radar reflection signal (echo) received by a synthetic aperture radar system and reflected from a rotating object will appear as a series of image points, or pulses, at the same range, but spaced apart by some apparent distance or frequency. By knowing the apparent distance (d) between adjacent image points, the range (R) to the target, the time of integration (T.sub.o) of the radar system, the velocity (V.sub.o) of the detecting aircraft, the angle (B.sub.o) to the target, and the wavelength of the aircraft's radar signal (.lambda.

Abstract: In an aircraft having an aircraft tracking system (ATS), the aircraft being a monitoring aircraft, the monitoring aircraft interrogates target aircraft in the vicinity of the monitoring aircraft in order to determine potentially dangerous situations. The target aircraft responds to the interrogations with parameter information which includes identification (ID). A method of interrogating the target aircraft comprises the steps of receiving unsolicited signals from the target aircraft in the vicinity of the monitoring aircraft. The received unsolicited signals are received by the monitoring aircraft at a first power level. Based on the first power level of the received unsolicited signals, the monitoring aircraft interrogates the target aircraft with a first interrogation signal.

Abstract: Radar apparatus for determining the height of a low-elevation target, the target being illuminated by a transmitter (7) and an antenna (3) via a TR-switch (6). Electromagnetic radiation reflected directly by the target and indirectly by the target via the earth surface is received by the antenna (3) and processed in a sum receiver (9, 10, 11), connected via the TR-switch (6) to the antenna (3), into complex sum signals, and in a difference receiver (12, 13, 14), into complex difference signals. A signal processor (15), receiving the complex sum signals and the complex difference signals, is provided with an algorithm which determines the height of the target. The algorithm enables the determination of the target height while the antenna remains directed at the target.

Abstract: A radar apparatus radiates search signals successively in different directions, receives echo signals and displays the signals so that surrounding conditions in a wide range of directions are displayed. The radar apparatus comprises a buffer memory for temporarily storing echo signals resulting from single search signals, a memory for storing echo signals supplied from the buffer memory and corresponding to single scans at corresponding memory elements, a timing adjusting amount setter for determining a timing adjusting amount in a distance direction, and a control arrangement for causing the buffer memory to write received echo signals thereinto based on the determined timing adjustment amount.

Abstract: A method for resolving range and doppler target ambiguities when the target has substantial range or has a high relative velocity in which a first signal is generated and a second signal is also generated which is coherent with the first signal but at a slightly different frequency such that there exists a difference in frequency between these two signals of .DELTA.f.sub.t. The first and second signals are converted into a dual-frequency pulsed signal, amplified, and the dual-frequency pulsed signal is transmitted towards a target. A reflected dual-frequency signal is received from the target, amplified, and changed to an intermediate dual-frequency signal. The intermediate dual-frequency signal is amplified, with extracting of a shifted difference frequency .DELTA.f.sub.r from the amplified intermediate dual-frequency signal done by a non-linear detector. The final step is generating two quadrature signals from the difference frequency .DELTA.f.sub.t and the shifted difference frequency .DELTA.f.sub.

Abstract: Method and apparatus for reducing the effects of noise jamming on coherent frequency or phase modulated signals employs a two channel radio signal processing system (15, 20) which accepts an input signal containing a desired signal (S) and a jamming signal (J) from a receiver input circuit (10). In the first channel (15), a hetrodyne mixer (30) and wideband filter (35) select the difference frequency component between the jamming signal and the desired signal [X(t)] while in the second channel (20), a local oscillator (45), mixer (50) and filter (55) function to select the difference frequency between the jamming signal and the local oscillator [Y(t)]. A third mixer (90) and bandpass filter (95) combines the outputs X(t) and Y(t) to provide the desired signal, including its original phase and frequency modulation components substantially independent and free of the jamming signal, to the receiver output circuit (12).

Abstract: Disclosed is a method and an apparatus which act as a retroreflector of circularly polarized electromagnetic radiation over a broad range of incident angles. The apparatus includes dipole antenna pairs which are orthogonally disposed in relation to one another about a central point to create antennas which consist, for example, of crossed dipoles but can be other circular polarization sensitive antennas. Antenna pairs are then arranged symmetrically in an array and interconnected by means which control the circular polarization of the returned signals to provide retroreflection of impinging signals while maintaining the same sense of polarization. The array thereby provides enhancement of the radar cross-section of a target when circularly polarized radar is employed. Conversely, the array can be connected so as to enhance opposite-polarization returns should there be any desire to do so.

Abstract: A radar of particular use at close range has a CRT that is scanned in a spiral fashion by applying phase quadrature sinusoidal signals to resonant deflection coils. A digitizer converts the radar return signals to multi-bit signals which are supplied to a memory with signals for alternate pixels stored in different halves of the memory. The apparatus reads out signals from one half of the memory during one scan and reads out signals from the other half of the memory during the next scan so that they are interleaved with the pixels on the display brightened by the first scan.

Abstract: An extended range transponder/antenna configuration comprises a standard, state-of-the-art transponder which is coupled to a long and narrow antenna by a loosely coupled coil. The coupling of the coil to the transponder must be loose for a tuned type transponder in order to maintain the high "Q" and to avoid detuning and damping. Both effects of lowering the "Q" and detuning or damping the transponder would have an adverse effect on the receiving function of the transponder and the reading range of the transponder. The RF-ID efficiency of the arrangement is generally optimized for this type of application by the long but narrow antenna solution and by the simple fact that coupling an antenna to a transponder, amplifies the emission of the transponders signal relative to the noise, thus improving the signal-to-noise ratio of the RF-ID system.