Abstract: An antenna system with network awareness includes a control system that points the antenna to a compatible network. The user provides the antenna with an input of a particular wireless service carrier and the control system begins searching for radio frequency signals that indicate the antenna is pointed at a compatible tower. Once a tower is located, the control system reads the carrier identification data transmitted from that tower to determine if the wireless carrier is compatible with the user's service. If an appropriate signal is not found, the control system will continue moving the antenna until another tower is found and the carrier identification information will again be checked. This process is repeated until a compatible tower is identified. Additional iterations can locate additional compatible towers. The antenna can be moved to a final position where the desired network signal is at the highest detected RF power.

Abstract: A method includes obtaining a signal that includes a plurality of cycles and generating a map that maps motion phases to the signal based on both an amplitude and a slope of the signal. A system includes a processor that identifies a set of motion signal timestamps, for a plurality of motion cycles in a motion signal indicative of cyclic motion of a moving object, based on a predetermined motion phase of interest and a phase-to-amplitude/slope mapping, wherein the set of motion signal timestamps correspond to a common signal amplitude. A method include identifying a peak of a plurality of peaks in a motion cycle of a noisy cyclic signal having irregular periodicity, wherein the peak corresponds to a point lying between two points with amplitudes below a predetermined threshold, comparing points before and after the peak with the peak, and identifying the peak as a local maximum when the peak is greater than the points.

Abstract: A radio frequency identification (RFID) monitoring system (12) for monitoring a plurality of RFID tags, and in particular for monitoring a plurality of vials incorporating such tags and stored at a low temperature, (eg.?80° C.) within a storage unit (10), for example a freezer. The RFID system (12) comprises an RFID reader (28) and at least one antenna (34a-34i) for transmitting and receiving RF signals to communicate with the RFID tags. The system (12) further includes an electronic switch (38), preferably a FET switch, interposed between the RFID reader and the at least one antenna (34a-34i) to connect a particular antenna (34a-34i) to the RFID reader (28) and transmit RF signals from the antenna (34a-34i) to the RFID tags. The switch (38) is controlled to intermittently connect the antenna (34a-34i) to the RFID reader (28) to regulate the power of the RF signal transmitted from the antenna (34a-34i). The system enables an RFID tag to operate at low temperatures.

Abstract: A system and method for providing a spectrally compact modulation of a tracking signal for directional beam scanning systems is presented. The system and method scans a tracking signal to produce a modulation of the tracking signal. When an impairment is anticipated, the system and method modifies the scan path to avoid the impairment and maintains the spectral compactness of the modulation of the tracking signal.

Abstract: A tracking system for maintaining an alignment between a reflector antenna and a source of electromagnetic radiation, includes a reflector for reflecting electromagnetic radiation generated from a electromagnetic radiation source, a receiver, and a rotary sub-reflector which is positioned in front of the reflector for deflecting the radiation reflected by the reflector to the receiver and for generating triggering signals for measuring the strength of signals of the reflected radiation, whereby the sub-reflector is arranged at an inclination with respect to the reflector by an offset angle.

Abstract: An electrical surveillance measures system for measuring direction of arrival (DOA), i.e., both azimuth and elevation, of a pulsed or continuous wave radar signal from a moving emitter. Either carrier frequency or pulse repetition interval (PARI) Doppler shift are used whereby the ratio of the Doppler shift is measured by a moving observer. The DOA is measured as a unit vector having basis vectors formed from a linearly independent set of observer's velocity vectors. The DOA unit vector has a linear part where the coefficients of the basis vectors are derived directly from the ratios of frequency or PARI measurements taken in three contiguous dwells. The DOA unit vector has a nonlinear part formed from the requirement that the DOA vector have unit magnitude. The unit vector is resolved in the system coordinates in which emitter azimuth and elevation are defined to allow computation of the latter two values.

Abstract: An array antenna system (40) has a plurality of radiators (44) for generating a set of beams (48), wherein axes of the beams are spaced apart from each other allowing the respective beams to illuminate separate areas of the earth or other receiving region. A sequence of positional offsets (52) is applied to the set of beams by either mechanically (108) moving the radiators to redirect the beams, or by introducing a phase or time-delay taper (84) to the phase shifters (80) or delay lines of a beam former (38) for each of the beams. The succession of positional offsets redirects the beams along a path offset from a central location (50) of each beam, and passing between the sites of adjacent beams. This provides for improved uniformity of illumination of the receiving region.

Abstract: In an antenna system for tracking a satellite, a prediction of the angular orientation of the satellite relative to the antenna as a function of time is obtained from the orbital parameters of the satellite. The mechanisms for controlling the angular position of the entire antenna structure then "drive" the entire structure so as to point the antenna beam towards the predicted position of the satellite as the satellite progresses in its orbit. The "drive" instructions are perturbed slightly so as to cause the antenna beam to "dither" slowly about the predicted satellite positions. The variations in signal strength produced by the dither are then used to determine the azimuth and elevation errors. The orbital parameters upon which the predictions are based are then adjusted so as to minimize the observed azimuthal and elevation errors. Because any error in the orbital parameters changes only very slowly, a relatively slow "dither" and a long time constant can be used in the correction process.

Abstract: A method of, and apparatus for, controlling the directional aiming of an antenna device including: scanning the antenna along with a conical path and detecting a directional point at which a detected level of reception along the conical path is turned from increasing to decreasing; scanning the antenna along a directional path defined by a center point of the conical path and the directional point, and detecting a signal source point at which a detected level of reception along the directional path is turned from increasing to decreasing; and setting a directional aiming of the antenna at the detected signal source point.

Abstract: A conical sweep array antenna has a flat antenna structure having a plurality of microstrip sources disposed in a plurality of sections. Preferably, each section includes a plurality of sources. The flat antenna also has at least one source disposed outside any of the sections. A phase-shifting device phase-shifts the plurality of sources to cause a conical sweep pattern of the flat antenna. Also, the phase-shifter device provides a constant phase-shift to the one source which is not disposed in any section. The presence of the nonphase-shifted source improves the radiating diagram of the antenna of the invention, particularly by reducing the coma lobe.

Abstract: A cooperative antenna tracking system for use at both ends of a radio link employs conical-scanning-type tracking at each end of the radio link to point a directional antenna guided by a continuous radio signal transmitted from an antenna at the other end of the link. A cooperative system between the two stations avoids pollution of the tracking in each station which might be caused by conical scanning at the other end of the link. Tracking pollution is avoided by time multiplexing tracking intervals between the two stations or by employing a tracker drive signal as a reference signal in a synchronous detector in each station to demodulate its own scanning frequency while sharply discriminating against signal variations produced by a scanning frequency at the other end of the link.

Abstract: A direction-finding interferometer (100) includes a novel autocalibration subsystem using bi-directional transmissions at a common frequency. The interferometer determines direction using a primary phase comparator (15) to assess the phase differences in signals transmitted by signal channels (13) from multiple antennas (11). The signal channels may include RF amplifiers (17), mixers (19) coupled to a local oscillator (23), IF amplifiers (21), and transmission lines.The autocalibration subsystem employs a frequency synthesizer (25) as a calibration signal source. The calibration signal path is directed between reversing switches (40) and couplers (33) in alternating directions via transmission lines (57 and 59). In either direction, the calibration is split so that part of the signals are coupled into the signal channels, and the remaining part is directed to a secondary phase comparator (131). The outputs of the primary and secondary comparators provide the data necessary for autocalibration.

Abstract: Discrimination between sidelobe and main beam reception of interference signals in a lobe on receive only radar is accomplished by a method of operation in which interference signals are stored and averaged for the radar receive beam positions of boresight, up, down, left and right. Interference signals received at boresight are compared with interference signals received at each off-boresight beam position. Interference signals received at boresight are also differenced with interference signals received at the off-boresight beam positions and the results are compared with beam width defining threshold factors. The determined values are applied to logic functions that indicate reception of interference signals outside of the main beam pattern.