An illustrative example embodiment of a detector device includes a receiver configured to receive radiation comprising a plurality of codes. Each of the codes is associated with one of a plurality of transmissions and each of the codes is distinct from the other codes. A processor is configured to obtain information corresponding to at least one predetermined phase code spectrum for the codes, determine a demodulated signal spectrum of radiation received by the at least one receiver, determine at least one characteristic of the determined demodulated signal spectrum, adjust the at least one predetermined phase code spectrum based on the determined characteristic to generate an adjusted phase code spectrum, and refine the determined demodulated signal spectrum based on the adjusted phase code spectrum to generate a refined demodulated signal spectrum.

A radar transmitter transmits a radar signal through a transmitting array antenna at a predetermined transmission period, and a radar receiver receives a reflected wave signal which is the radar signal reflected by a target through a receiving array antenna. A transmitting array antenna and a receiving array antenna each include multiple subarray elements, the subarray elements in the transmitting array antenna and the receiving array antenna are linearly arranged in a first direction, each subarray element includes multiple antenna elements, the subarray element has a dimension larger than a predetermined antenna element spacing in the first direction, and an absolute value of a difference between a subarray element spacing of the transmitting array antenna and a subarray element spacing of the receiving array antenna is equal to the predetermined antenna element spacing.

Techniques that facilitate reconfigurable transmission of a radar frequency signal are provided. In one example, a system includes a signal generator and a power modulator. The signal generator provides a radar waveform signal from a set of radar waveform signals. The power modulator divides a local oscillator signal associated with a first frequency and a first amplitude into a first local oscillator signal and a second local oscillator signal. The power modulator also generates a radio frequency signal associated with a second frequency and a second amplitude based on the radar waveform signal, the first local oscillator signal and the second local oscillator signal.

Techniques that facilitate reconfigurable transmission of a radar frequency signal are provided. In one example, a system includes a signal generator and a power modulator. The signal generator provides a radar waveform signal from a set of radar waveform signals. The power modulator divides a local oscillator signal associated with a first frequency and a first amplitude into a first local oscillator signal and a second local oscillator signal. The power modulator also generates a radio frequency signal associated with a second frequency and a second amplitude based on the radar waveform signal, the first local oscillator signal and the second local oscillator signal.

A method of signal processing for suppressing at least one sidelobe of an autocorrelation function between a received code sequence and a mismatched filter coefficient vector comprises: setting a filter coefficient vector; modifying the filter coefficient vector, thus generating a modified filter coefficient vector; correlating the modified filter coefficient vector with the code sequence yielding an autocorrelation function comprising a main peak and sidelobes; generating a performance parameter that describes the sidelobe suppression of the autocorrelation function; setting the modified filter coefficient vector as the new filter coefficient vector for a subsequent iteration if the performance parameter shows a performance improvement; and discarding the modified filter coefficient vector if the performance parameter shows no performance improvement.

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 detection device includes a transmitter for outputting an impulse signal and a receiver for receiving and processing a reflected signal obtained by reflecting the impulse signal from a target. The receiver includes a sample and extension unit that samples a received signal and extends a duration of a value obtained by sampling the received signal to form an extended signal extended to a frequency lower than a frequency of the reflected signal.

A radar apparatus includes: a radar transmitter transmitting a radar signal; and a radar receiver receiving a reflection wave signal being a reflection of the radar signal on a target. The radar transmitter includes: a radar transmission signal generator that generates the radar signal composed of a transmission code with each sub-pulse given a predetermined phase shift; and a transmission radio unit that transmits the radar signal generated by the radar transmission signal generator in a predetermined transmission cycle. In radar signals transmitted by the transmission radio unit in a predetermined number of transmission cycles, code imbalances of transmission codes are included in all of four quadrants of the IQ plane. Each of the code imbalances is an imbalance between the positions where a plurality of sub-pulses constituting a transmission code included in a radar signal transmitted in each of the transmission cycles are mapped on the IQ plane.

A DS-SS radar 10 detects an object in such a way that a code generator 21, an oscillator 32, and an antenna 24 repeatedly send a sending signal modulated with a predetermined-frequency code generated by the code generator 21, an A/D converter 45 samples the code, included in the reflected wave of the sending signal reflected by an object, with a sampling period lower than the period of the code, and a correlator 46 calculates the correlation between the reference code, generated by re-arranging the code from the code generator 21 at an interval of Nsp, and the sampling data converted by the A/D converter 45.

Aspects of the present disclosure are directed to radar and radar processing. As may be implemented in accordance with one or more embodiments involving multi-input multi-output (MIMO) co-prime radar signals transmitted by a plurality of transmitters and reflected from at least one target, the reflected radar signals are processed by resolving ambiguities associated with a range-Doppler detection based on unique pulse repetition frequencies (PRF)s associated with respective chirp groups of the reflected radar signals. Phase compensation is applied to compensate for motion-induced phased biases and, thereafter, Doppler estimates are reconstructed to provide a dealiased version of the reflected radar signals.