A chip-implementation of a millimeter wave MIMO radar comprises transmitters for transmitting short bursts of digitally modulated radar carrier signals and receivers for receiving delayed echoes of those signals. Various signal formats defined by the number of bits per transmit burst, the transmit burst duration, the receive period duration, the bitrate, the number of range bins, and the number of bursts per scan, facilitate the choice of modulating bit patterns such that when correlating for target echoes over an entire scan, the correlation codes for different ranges and different transmitters are mutually orthogonal or nearly so. In the event of imperfect orthogonality, simple orthogonalization schemes are revealed, such as subtraction of strong already-detected target signals for better detecting weaker signals or moving targets that are rendered non-orthogonal by their Doppler shift.

A maritime radar system is provided, comprising a transmitter, a receiver, and one or more processors arranged to provide range and azimuth discrimination of a detection area by performing a delay/Doppler analysis of the echo of a single beam transmitted by the transmitter and received by the receiver.

It is described a radar system (100), comprising: i) a transmitter (110) having a transmitter carrier characteristic, configured to transmit a code signal (S); ii) a receiver (120) having a receiver carrier characteristic, configured to receive an echo (E) of the code signal (S); and iii) a control unit (130) configured to: a) identify a carrier characteristic tracking path (T) between the transmitter (110) and the receiver (120), b) estimate an offset between the transmitter carrier characteristic and the receiver carrier characteristic based on the identified tracking path (T), and c) compensate for the offset, in particular establish coherency, based on the estimation. iv) The tracking path (T) comprises hereby a communication path that is at least partially independent of the code signal (S) and the echo (E) of the code signal (S).

A pulse radar includes pulse generation circuitry that generates a transmission pulse signal, radio frequency transmission circuitry that transmits a radio frequency signal obtained by performing a frequency conversion on the transmission pulse signal, radio frequency reception circuitry that converts a reflected-wave signal to a reception pulse signal, the reflected-wave signal being a part of the radio frequency signal reflected back from an object to be measured and received via a reception antenna, signal processing circuitry that calculates a distance between the object and the pulse radar, detection circuitry that detects a main pulse, and correction filter coefficient calculation circuitry that calculates an amount of delay and a phase difference of the one or more error pulses with reference to the main pulse to update a parameter of the correction filter circuitry. The correction filter circuitry updates a filter characteristic using the updated parameter.

A transmitting array antenna includes a second antenna group placed in a position inside a first antenna group in a first direction and a position different from the first antenna group in a second direction. A receiving array antenna includes a fourth antenna placed in a position outside a third antenna group arranged in the first direction and a position different from the third antenna group in the second direction. An interelement spacing between a receiving antenna of the third antenna group located at an end on a second side is identical to an interelement spacing in the first direction between a transmitting antenna of the first antenna group on the first side and each of the second antenna group. In a case where the first antenna group and the third antenna group are identical in position in the second direction, positions of antennas are different.

A radar device is mounted on a vehicle, which is a moving object, and includes a doppler correction phase-rotation controller and a phase rotator. Based on the speed of the vehicle, the doppler correction phase-rotation controller calculates a Doppler correction phase-rotation amount for correcting a Doppler frequency due to movement of the vehicle. By using the Doppler correction phase-rotation amount, the phase rotator pre-corrects Doppler frequency components with respect to a radar transmission signal in each transmission interval of the radar transmission signal.

Systems and methods are disclosed to determine an unambiguous radial velocity for weather phenomena using weather radar that is not limited by the Doppler Dilemma. Some embodiments include transmitting a complex waveform and using the returned electromagnetic signal to determine the unambiguous radial velocity.

A radar apparatus includes: a radar transmission signal generator, which in operation, outputs a plurality of radar signals; a switching controller, which in operation, switches among plurality of transmitting antennas in sequence in a determined order to every one radar signal transmission period; and a radio transmitter, which in operation, transmits one radar signal every one radar signal transmission period through a allocated transmitting antenna to which switching has been made. A plurality of transmission timings at which the allocated transmitting antennas to which switching have been made transmit each of the plurality of radar signals within a determined period have identical time differences from a reference timing within the determined period.

A radar apparatus includes a radar transmitter and a radar receiver. The radar receiver includes sampling circuitry, correlation calculation circuitry, a plurality of adder circuitry, a plurality of Doppler frequency analysis circuitry and Doppler frequency correction circuitry. The Doppler frequency correction circuitry, which in operation, (i) determines whether or not a folding in a Doppler frequency included in a reflected wave signal is present according to an amplitude difference or phase difference between two of peak spectra of results of analyses performed by the plurality of Doppler frequency analysis circuitry, and (ii) makes a correction to the Doppler frequency included in a reflected wave signal on the basis of the results of the analyses in a case it is determined that the folding is present.

Apparatus and methods are presented for characterising the environment of a user platform. In certain embodiments RF signals are transmitted and received through an antenna array having a plurality of elements activated in a predetermined sequence, and received signals are manipulated with round-trip path corrections to enhance the gain of the array in one or more directions. Objects in those directions are detected from the receipt of returns of transmitted signals, and the manipulated received signals processed to estimate range to those objects. In other embodiments RF signals transmitted by one or more external transmitters are received and manipulated to enhance the gain of a local antenna array or antenna arrays associated with the one or more transmitters to enhance the gain of the arrays in one or more directions. Objects in those directions are detected from the receipt of reflected signals from the transmitters, and the manipulated received signals processed to estimate range to those objects.