摘要:
A method of processing a plurality of received digitized signals may include determining a plurality of cross-correlation coefficients for the plurality of received digitized signals; forming a cross-correlation coefficient vector including the plurality of cross-correlation coefficients; and determining an evaluation value for at least some of the plurality of cross-correlation coefficients. The determining the evaluation value may include: pre-selecting a predefined number of cross-correlation coefficients from the cross-correlation coefficient vector and deleting the pre-selected number of cross-correlation coefficients from the cross-correlation coefficient vector; after the pre-selection, determining an averaging value using at least one of the non-preselected cross-correlation coefficients of the cross-correlation coefficient vector; and determining the evaluation values based on the respective value of the pre-selected cross-correlation coefficient and the averaging value. The method may further include selecting one or more cross-correlation coefficients based on the determined evaluation values; and further processing based on the selected one or more cross-correlation coefficients.
摘要:
A radar system is disclosed for forming a scanning receive beam from signals received by a phased array having a plurality of sub arrays. An exemplary radar system includes a plurality of phase units each configured to receive a signal from one or more sub arrays. Each phase unit includes a waveform generator configured to generate an analog waveform having a frequency corresponding to a time-varying phase shift. Each waveform generator is arranged to digitally generate the analog waveform, and output a comparison of the received signal with the waveform, incorporating the time-varying phase shift. The system further includes a combining unit configured to combine the outputs from the plurality of phase units to form a scanning receive beam.
摘要:
An antenna system may include an antenna array which includes a plurality of radiating elements. The system may also include a phase shifter controller and algorithm to apply a non-periodic modulation to an excitation of each radiating element.
摘要:
The present invention lies in the field of antennas for land cellular radio communications networks, and it relates to a remote control method for adjusting the tilt of the radiation pattern relative to the horizontal of the antennas of a base station. The invention also relates to an antenna fitted with means for adjusting its tilt and to a system for remote control of the tilt. The technical field of the invention is active antennas (also known as “smart” antennas or as “adaptive” antennas) for networks for communicating with mobile telecommunications terminals. According to the invention, an antenna for a land cellular telecommunications network, the antenna comprises radiating elements and feeder means for feeding said radiating elements with radio frequency signals; said feeder means include electronic phase shifter means for obtaining phase shifts between said signals so as to enable the tilt of the radiation pattern in a vertical plane to be adjusted remotely.
摘要:
A radar system having a phased array antenna for transmission and a digital beam forming antenna for reception for observing a plurality of targets by transmitting transmission pulses to the respective targets comprises a subtraction control circuit, a transmission timing control circuit and a transmission beam direction control circuit. The substraction control circuit calculates a required number of transmission pulses (beams) to be transmitted for each of transmission cycles in accordance with detected Doppler frequencies of the targets, so as not to cause ambiguity on the detected Doppler frequencies, and determines a beam direction for each of transmission beams. The timing control circuit and beam direction control circuit control transmission timing and direction of the beams.
摘要:
An antenna control data transfer system having antenna elements, phase shifters changing the phase of electromagnetic waves transmitted or received by the antenna elements, and phase shifter control circuits controlling the phase shifters, wherein each of the phase shifter control circuits includes an address holding circuit storing an address for identifying the phase shifter control circuit, a data input circuit for receiving data, and a data output control circuit for selectively outputting the received data or inhibiting the data output in accordance with a control signal from a signal processor.
摘要:
A programmable beam transform system is disclosed for performing both beam steering and beam shaping operations in a phased array antenna. A programmable beam transform control circuit is responsive to a plurality of input signals for selectively generating and applying a plurality of control signals to each intelligent phase shift control circuit in an array of phase shift control circuits/phase shifters/antenna elements. Each phase shift control circuit simultaneously modifies the plurality of control signals applied thereto as a function of its internally-stored data to develop its own phase shift command signal which is used by its associated phase shifter to phase shift that portion of the total energy applied thereto. On transmit, the phase-shifted energy outputs from the phase shifters in the array are then respectively transmitted by the associated antenna elements in the array to form the desired beam pattern at the desired beam position; and on receive the complementary function occurs.
摘要:
A frequency agile radar system allows tracking of noncooperative targets with high accuracy. The system is particularly useful in an automatic landing system aboard an aircraft carrier. The radar employs an electronically steered planar array antenna system in which a symmetrical pencil beam of 1.degree. beamwidth is steered in 1/2.degree. steps in a raster scan. A space-stabilized acquisition window allows target acquisition, and target scanning modes are chosen as a function of target range. At far range, target scan is effected by those four beam raster positions which bracket the target whereas when the target is at near range where its cross section is larger than a single beamwidth, the raster is "ballooned" to paint or cover the target fully. The computed track of the target provides a continuing update of autopilot command signals radioed to the target to bring it to and hold it on a selected glideslope which effects the automatic landing.