A radar apparatus includes a transmitting analog front-end circuit, a plurality of antenna ports, a switching controller, a switching circuit, and a receiving analog front-end circuit. The transmitting analog front-end circuit generates a transmitting signal according to a carrier wave signal. A frequency of the carrier wave signal changes with time during a frequency sweep period of the carrier wave signal. The antenna ports are respectively configured to receive an echo signal corresponding to the transmitting signal. The switching controller is coupled to the transmitting analog front-end circuit and configured to generate a control signal according to the frequency sweep period of the carrier wave signal. The switching circuit is coupled to the antenna ports and the switching controller, configured to select one of the antenna ports to receive the echo signal according to the control signal, and coupled to the receiving analog front-end circuit.

Techniques and apparatuses are described for radar angular ambiguity resolution. These techniques enable a target's angular position to be determined from a spatial response that has multiple amplitude peaks. Instead of solely considering which peak has a highest amplitude, the techniques for radar angular ambiguity resolution select a frequency sub-spectrum, or multiple frequency sub-spectrums, that emphasize amplitude or phase differences in the spatial response and analyze an irregular shape of the spatial response across a wide field of view to determine the target's angular position. In this way, each angular position of the target has a unique signature, which the radar system can determine and use to resolve the angular ambiguities. Using these techniques, the radar can have an antenna array element spacing that is greater than half a center wavelength of a reflected radar signal that is used to detect the target.

A radar antenna includes a plurality of horns in the annular space of a munition nose cone. The horns are disposed near the exterior surface of the nose cone. In a further aspect, the nose cone may be injection molded or additively manufactured so that the horns are embedded a known distance from the exterior surface. In a further aspect, the horns placed in either a transmit mode or a receive mode so as to maintain a minimum special separation between transmitting horns and receiving horns.

A level radar device with adaptive, angle-dependent transmission power adjustment, which calculates the maximum permissible transmission power of the transmitted signal on the basis of the radiation direction of the transmitted signal and the radiation characteristic of an antenna.

According to one aspect, a radar-radiometric imaging method is disclosed that includes cyclical observation, with a time period T, of a selected space section due to antenna beam rotation with a period T.sub.a (T.sub.a≤T) around a rotation axis misaligned with the antenna's beam axis, along with the simultaneous change of the spatial orientation of this rotation axis using an antenna positioning device to ensure survey of the selected space domain for the time T without gaps.

A vehicle radar sensor unit (2) arranged to acquire a plurality of radar detections, and including an antenna arrangement (3), a transmitter unit (4), a receiver unit (5) and a processing unit (6). The antenna arrangement (3) has at least two transmitter antennas (7, 8) and at least two receiver antennas (9, 10, 11, 12), where two transmitter antennas (7, 8) have a vertical spacing (h) between their respective phase centers (17, 18) that exceeds half the free-space wavelength of the transmitted signal. The processing unit (5) is arranged to determine a first radial velocity of each radar detection by tracking the change of radial distance (r) to each radar detection for a plurality of radar cycles; determine a second radial velocity that best matches the first radial velocity; track a plurality of measured heights (z) as a function of radial distance (r); and to choose a measured height (z.sub.GT) among the tracked measured heights (z) that has a minimal change from radar cycle to radar cycle.

The present invention is provided with: an antenna 23 having an antenna surface 28 for radiating radio waves so as to have a prescribed plane of polarization; a second rotary mechanism 22 which is connected to the antenna 23 and which rotates the antenna 23 about a second rotation axis I2 that is set in a normal direction orthogonal to the antenna surface 28; and a first rotary mechanism 21 which is connected to the second rotary mechanism 22 and which rotates the antenna 23 and the second rotary mechanism 22 about a first rotation axis I1 that is set in a direction slanted with respect to the second rotation axis I2.

An embodiment of a radar subsystem includes at least one antenna and a control circuit. The at least one antenna is configured to radiate at least one first transmit beam and to form at least one first receive beam. And the control circuit is configured to steer the at least one first transmit beam and the at least one first receive beam over a first field of regard during a first time period, and to steer the at least one first transmit beam and the at least one first receive beam over a second field of regard during a second time period.

Systems and methods for providing wide field-of-view radar arrays. Quadrature phase-shift keying (QPSK) beam forming reduces side lobes by applying a phase shift to transmitted signals to selected transmitting antennas. Super-hemispherical radar coverage at high gain in both broadside and end-fire directions is provided by beam directing elements mounted to a printed circuit board.

A drone detection radar configured to identify, from information present on returns reflected from a target, the presence of a drone, by identification, within Doppler information on the returns, of: i) Doppler signals being characteristic of rotating parts of a motor; ii) Doppler signals being characteristic of rotating parts of a blade; and, by identification from temporal information in the reflected returns; and iii) signals being characteristic of flashing of the blade of a drone. The target is assumed to be a drone if signals i, ii, and iii are present above respective predetermined thresholds. The largest return from a drone is often from the body, but this is often filtered by a clutter filter. The identified parameters therefore improve detection ability. The characteristic form of the Doppler signals in some instances allow the body return to be implied, thus providing information as to drone velocity.