Abstract: A phased-array antenna (14) is disclosed including modules (12) that respond to optic signals provided by a central processor (16) vai an optic feed network (18). In a transmit mode of operation, the central processor provides optic transmit signals to the modules, controlling the phase and attenuation of the various signals to accomplish the desired steering of the antenna beam produced by the array. A mixer or avalanche photodiode (42) in each module provides suitable optical-to-RF power conversion for the input signal to allow antenna elements (44) in the module to radiate the desired electromagnetic beam. During a receive interval, a received electric signal produced by the antenna elements is combined by the mixer with a local oscillator frequency optic signal applied to the mixer by the central processor. As a result, the RF frequency of the received signal is reduced to an IF frequency for low-cost amplification by an amplifier (52).

Abstract: A monopulse antenna array arrangement includes a transmit-receive processor (TR Proc) associated with each antenna element. Each TR Proc has a port associated with the radiating element and at least two further ports, one for a sum beamformer and another for a difference beamformer. Within each TR Proc, a switching arrangement allows transmitter signal to flow through a phase shifter and transmit amp during transmission, and allows received signal to flow through a low-noise amp and the same phase shifter on reception. Each TR Proc includes a coupling arrangement with a second phase shifter and a second output port, adapted to be coupled to a difference beamformer during reception.

Abstract: A modular direct radiating antenna system for producing highly contoured beam patterns is disclosed. The system comprises a plurality of array modules, each having a number of radiation elements. An intramodule feed network is provided to communicate RF energy between a module port and the radiation elements in an equal-power, equal-phase relationship. A second feed network, an intermodule feed network, is provided to communicate RF energy between an antenna system port and the respective module ports. The second feed network is adapted to couple the power and adjust the electrical path lengths so that the RF power communicate between the respective module ports and the system port is of predetermined relative amplitudes and phases. The intermodule excitation power and phase distribution across the entire planar array aperture produces the desired contoured beam to encompass a required area.

Abstract: An electronically steered phased array antenna system. The system includes phased array radar antenna having a microwave phased shifter for inserting a predetermined amount of path delay into each of the radiated elements of the antenna. It also includes a beam steering controller connected to the microwave phase shifter which is adapted to control the phase shifter according to predetermined parameters relating to the antenna to maximize its performance. An electronically erasable programmable read only memory device is disposed on the antenna itself for storing the predetermined parameters relating to the antenna. The memory device is connected to the controller and by inputting its data into the memory of the controller converts the controller from a generic device to a dedicated controller for the antenna in question. The memory device can be reprogrammed without removing it from the antenna for changes in the antenna configuration data.

Abstract: A circular waveguide section which is suitably excited with a TM.sub.01 and two spatially orthogonal TE.sub.11 modes to form a cosine-squared-on-a pedestal amplitude distribution at the outputs of the circular waveguide. The resulting cosine-squared-on-a-pedestal amplitude taper may be distributed to the elements of a circular phased array to form a low sidelobe antenna. Since the waveguide is a reciprocal element, it can be used in a receiver as well as a transmitter.

Abstract: A conformal array antenna system is disclosed comprising a structural base body having a shape suitable for a surface of an airplane or a ship, and a plurality of antenna units disposed on the structural base body. Signals received by these antenna units are converted into digital signals and fed to a digital beam forming circuit which synthesizes such digital signals to form a multiplicity of beams. The antenna units and the digital beam forming circuits may be connected by electrical transmission lines or optical fibers.

Abstract: The corporate feed network employs light emitting opto-electronic components, such as laser diodes (12), connected together in a string (14) for distributing RF, microwave, MMW, digital signals, and pulse modulated light. Each diode provides two ports or facets which are coupled to optical fibers (16, 18) to connect to an active phased array antenna, for example. The diodes are selected in number and impedance to provide a good wideband impedance match to the RF/microwave/MMW/digital driving source. Multiple series strings of diodes may be employed, connected in parallel for larger corporate feed structures.

Abstract: In a radar having electrical transmitting and receiving circuitry, and an antenna for the radiation of microwave signals, there is provided an optical feed system which couples the antenna with the transmitting and receiving circuitry. The feed system includes a set of optical multiplexers interconnected by sets of optical fibers. Microwave energy of the radar is converted to optical radiation for communication to the antenna, and then converted back to the microwave energy. Electro-optic modulators and photoelectric detectors provide for the energy conversion. A plurality of signals, including both signals having the transmit waveform as well as control signals, can be simultaneously coupled via the optical fibers by utilization of radiation of differing frequencies. The multiplexers include dichroic mirrors for separation of the radiations of the differing frequencies.

Abstract: An antenna array for combining in space microwave energy from a number of cillators, such as IMPATT diodes, which are controllable by injection locking. The array has elements individually driven by the oscillators, but an injection locking signal is provided in the usual manner only to the oscillator of a central element. The other oscillator are injection locked through mutual coupling between the central element and the other elements so that coherent radiation is output by the array. The radiation may be steered by phase shifters between the elements and their oscillators.

Abstract: An electronically steerable phased array radar antenna system for transmitting and receiving broadband linear FM signals is detailed. The antenna comprises a plurality of subarrays, each of which are connected by circulator means to a transmit-receive module. The highly linearized FM waveform is fed to the transmit-receive module, and a CW waveform is fed to a phase shifter in the module. The phase shifter applies a frequency offset to the CW waveform which is then added to the linear FM wideband signal for each antenna subarray. This frequency offset serves a beam steering function and can be considered a synthetic time delay.

Abstract: Conventionally, if several tasks have to be carried out simultaneously by receivers and transmitters, then a number of them are required, each having its own antenna.By employing the invention a single receiver or transmitter having one antenna can carry out a number of simultaneous tasks.A receiver has an array of antenna elements which receives signals and transmits them along conductors. Junctions include variable control means to apply a variable proportion of the signals on a conductor to one of a series of channels, each junction also giving a particular variable phase shift. By correctly selecting the amplitude and phase shift the outputs on the channels correspond to signals from respective directions of sensitivity of the receiver, and may be considered to represent a number of beams.

Abstract: A feed device for a sweep beam array antenna which has a plurality of elementary antennae combined into a plurality of sub-arrays having a predetermined overlap at their ends. Each sub-array includes a plurality of elementary groups, each elementary group including N elementary antennae. Each elementary group is fed by a feed circuit having N inputs and N outputs. Circuitry is provided for grouping together an arbitrary number of said elementary groups to form an assembly comprising MN elementary antennae, where M is greater than N, and MN antennae are the number of antennae in a sub-array. This circuitry is connected to an energy distributor and includes a plurality of divider distributor circuits, each one coupled to an output of the energy distributor. Each divider distributor circuits has M outputs. The circuitry also includes a plurality of adder distributor circuits, each one having N outputs coupled to the N inputs of a respective one of said elementary groups.

Abstract: This invention utilizes an opto-electronic matrix switch to select a set of fixed value phase shifters. Signals which are selectively phase shifted by this apparatus may be introduced into the signal path of each antenna element of a phased array antenna. In one embodiment the input signal is converted into an intensity modulated optical signal which is then split between paths of different length to provide different delays and hence different phase shifts. The matrix then selects a particular set of the phase shifted signals which are converted back to electrical signals and fed to the antenna array elements.

Abstract: An electronic scanning antenna which effects radiation beam scanning based on a phase electronic scanning. The antenna has a plurality of radiation aperture units and power is fed concurrently to the plurality of radiation aperture units within a range of a small elevation angle. Thus, the degradation of a beam is reduced and a narrow beam can be formed with a high efficiency. Further, the antenna is configured wherein an electric field distribution on a radiation aperture plane formed by at least one radiation aperture is set so as to correspond to an electric distribution based on a predetermined design, thereby always normally maintaining aperture efficiency and radiation characteristic of a radiation beam over a range of a predetermined scanning angle.

Abstract: A radar system includes a clock for generating timing signals of a predetermined period, an exciter for generating high frequency signals of predetermined frequencies in sequence and in time series in response to the timing signals, a transfer switch and an antenna. The transfer switch has an input terminal and a plurality of output terminals. The input terminal receives the high frequency signals and provides one of these high frequency signals at each of its outputs in accordance with the received timing signals. The antenna is connected to receive the high frequency signals from the output terminals of the transfer switch to form radar beams corresponding to the high frequency signals.

Abstract: A phased array antenna system capable of scanning at rates faster than the information rate of signals being received to prevent the loss of information during the scanning process. The phased array is configured to add the capability to provide multi-dimensional separation of multiple signals to enable measurement of direction of arrival and frequency, and to eliminate the sensitivity loss due to sampling usually encountered with such rapid-scan systems. The array antenna system is comprised of the means to form multiple, time-sequenced responses, each response corresponding to a different beam of sensitivity. The beams scan the full coverage sector and together with each other form a contiguous set of beams that both fill the coverage sector at any one time and also synchronously scan the full coverage sector.

Abstract: Steerable phased array antennas of the tapered type in which the antenna ment power is maximum at the center of the array and tapers off on either side thereof. The phase shifters of each antenna element are of the binary digital type with the number of stages and hence the phase accuracy being maximum for the high power center antenna elements and tapering off on either side thereof. Redundant stages for the binary phase shifters can be provided to increase reliability.

Abstract: Subarray amplitude tapering is a simple, lower cost method of generating low sidelobes in an antenna's far field pattern. Unfortunately, this simple technique also generates unwanted grating lobes. Placing the exact amplitude taper at the element outputs produces the desired far field pattern, but the architecture is complicated and expensive. An alternative to these two techniques is a design process that entails placing amplitude tapering at subarray outputs and element amplitude tapers that are identical between corresponding elements in groups of identical subarrays. In this way, the amplitude taper approximates the desired taper much better than subarray tapering alone, yet groups of subarrays are identical so that the design remains very simple.

Abstract: A miniaturized microwave transmission link comprises short links of dielectric coated fine wire overlying a ground plane between signal coupling/launching pins of MICs. A dielectric cap is provided at each wire-pin termination and a layer of conductive foil is pressed onto the overall structure to form a conformal tunnel/channel microwave transmission line configuration. The resulting tunneline, and/or channeline transmission line structure may connect MICs in a compact housing or provide access from external terminals to leads in a IC chip.

Abstract: The circular phased array antenna includes a plurality of radiating elements spaced about the circumference of a mounting ring. The radiating elements are fed with r.f. currents having relative phase and amplitude distribution to form a focused beam from the antenna. The beam is steerable to a selected direction. The monitor system includes a probe element mounted near each radiating element, phase shifters and couplers for combining signals from the probes into a transmission line. The amplitude of the transmission line signal is compared with a known value of signal for a normally operating antenna for each beam direction. A failure alarm is generated whenever the difference between the compared signals exceeds tolerance.

Abstract: A narrow-band phase shift beamformer system is disclosed. The outputs from the elements in a transducer array are each divided into two components whose amplitudes are respectively proportional to the sine and cosine of the required phase shift, which are then processed so that the steered beam may be formed by coherent summation. The proportionalities of the respective sine and cosine components are achieved by switched capacitor circuits, which are preferably implemented by LSI circuits, permitting substantial hardware savings and yielding highly accurate component proportionalities.