Abstract: A polarization twist, space-fed, E-scan planar phased array antenna. The phased array antenna incorporates a polarization twist, space-fed architecture. A plurality of unit cells are formed wherein each cell incorporates a large plurality of phased array elements and associated phase shifters. The space-feed architecture enables 2-bit phase shifters to be employed while still producing low antenna sidelobes. The phased array elements, phase shifters, and associated control circuits for controlling the phase shifters are all preferably formed on one surface of a MMIC substrate. This further simplifies significantly the cost and complexity of manufacturing and testing the E-scan phased array antenna. The antenna can therefore be used in applications where an E-scan phased array antenna would have been too costly to employ.

Abstract: A radar system and method for obtaining low sum and difference side lobe patterns from a phased array antenna comprising radiators distributed amongst four quadrants A, B, C, and D. The quadrants are arranged in a clockwise order of A, B, D, and C. Each quadrant is further divided into an inner portion and an outer portion. The monopulse sum pattern is determined by adding signals received by radiators in the A quadrant, B quadrant, C quadrant, and D quadrant. The elevation difference pattern is determined by subtracting a CD sum consisting of signals received by radiators in the C outer portion and the D outer portion from an AB sum consisting of signals received by radiators in the A outer portion and the B outer portion. The azimuth difference pattern is determined by subtracting a BD sum consisting of signals received by radiators in the B outer portion and the D outer portion from an AC sum consisting of signals received by radiators in the A outer portion and the C outer portion.

Abstract: A radar lens 14 is made from a conventional Fresnel lens 10, but replaces the conventional curved surface 32 with a stepped approximation thereto 22, 24, 26, preferably of three steps. The thickness of the stepped lens 14, at each step, is a half-wavelength or a multiple half-wavelength of the radar operating frequency in the medium of the lens 14. The half-wavelength or multiple half-wavelength separation of the steps 22, 24, 26 causes reflections from the front 16 and rear 18 surfaces to cancel, thereby minimizing the (undesirable) standing wave between the lens 14 and the feed horn or feed horns 46, 48, 50. This avoids the necessity of reducing the standing wave by presenting the curved or stepped side 18 forward. The planar side 16 of the lens 14 (unlike the stepped side 18) doesn't need to be protected from road debris. The lens 14 can therefore be molded as an integral unit of a radome, desirable in the automotive setting.

Abstract: A modular radar system using both FM/CW and pulse waveforms for automotive collision avoidance applications.

Abstract: A spatial power combiner includes a circularly corrugated horn 26, a meniscus lens 28, an amplifier array 16, and a layer of microwave absorbing material 34 on a housing interior 32. The lens 28 receives polarized microwave radiation from the horn 26 and collimates it, renders it in phase and with nearly uniformly amplitude, and distributes it across the lens aperture. The amplifier array 16 amplifies the radiation and re-radiates it, orthogonally polarized, to the lens 28, which focuses it back down the horn 26. An array of parasitic micropatches 24 between the lens 28 and amplifier array 16 provides impedance matching. A quarter-wave anti-reflecting coating 30 covers both surfaces of the lens 28. The microwave absorbing material 34 reduces or prevents resonance of higher order modes.

Abstract: A bi-directional spatial power combiner grid amplifier has an array of parasitic elements between the lens and the amplifier. The elements have different impedances to radiation of a first polarization (incident radiation) and of a second polarization which is orthogonal to the first (amplified radiation), thereby providing impedance matching to both the input and the output of the grid amplifier. The elements preferably are separated slots or dipoles (some in each direction of polarization), crossed slots or dipoles, or micropatches.

Abstract: The present invention is a high efficiency bi-directional spatial power combiner for extremely high frequency signals. In one embodiment, orthogonally polarized electro-magnetic waves are used to isolate signals going into and out of a planar array of amplifiers. A dual mode horn transmits vertically polarized fields to a MMIC planar array of amplifiers. Vertically polarized array elements receive the signals, amplify them, and retransmit back to the horn using horizontally polarized array elements. An ortho-mode transducer on the horn provides isolation for the two polarized signals. The backside of the array can be used for a heat sink, and to provide access for DC biasing of the array elements. In a second embodiment, monolithic grid oscillators are used in lieu of power amplifiers with orthogonal polarization array elements. The input signal and the output signal are of the same polarization. A circulator is used in lieu of an ortho-mode transducer to isolate the input signal from the output signal.