A receive path arrangement of a radar sensor of FMCW type comprising a first and second receive path configured to receive reflected radar signals for detection and ranging of objects in a space around the radar sensor; the first receive path configured to provide reflected radar signals between a first and second beat frequency to a first analogue to digital converter for subsequent digital signal processing and wherein; the second receive path includes a second-receive-path filter configured to provide filtered signals by attenuation of the reflected radar signals having frequencies below an intermediate beat frequency, the intermediate beat frequency between the first and second beat frequencies, the second receive path further including a second-receive-path amplifier arrangement configured to provide amplified signals by amplification of the filtered signals and provide the amplified signals to a second analogue to digital converter for subsequent digital signal processing.

A transmission radar (1) divides each of multiple frequency bands in such a manner that differences between center frequencies in respective frequency bands after the division are equal, and transmits, in time division manner, transmission signals of which transmission frequencies are the center frequencies in respective frequency bands after the division; a rearrangement processing unit (13) rearranges each of the reception video signals converted by the reception radar (5) in such a manner that sets of reception video signals corresponding to the multiple frequency bands before being divided by the transmission radar (1) are arranged in a row; and a band synthesis processing unit (14) performs a band synthesis on each of the reception video signals rearranged by the rearrangement processing unit (13).

An autonomous system with no Customer Network Investment is described, wherein the system is configurable to operate on in a band in addition to the LTE band. Such system allows the definition of hybrid operations to accommodate the positioning reference signals (PRS) of LTE and already existing reference signals. The system can operate with PRS, with other reference signals such as cell-specific reference signals (CRS), or with both signal types. As such, the system provides the advantage of allowing network operator(s) to dynamically choose between modes of operation depending on circumstances, such as network throughput and compatibility. The system further enables information collected at a network device to be processed at a locate server without involving any processing at the network device.

An autonomous system with no Customer Network Investment is described, wherein the system is configurable to operate on in a band in addition to the LTE band. Such system allows the definition of hybrid operations to accommodate the positioning reference signals (PRS) of LTE and already existing reference signals. The system can operate with PRS, with other reference signals such as cell-specific reference signals (CRS), or with both signal types. As such, the system provides the advantage of allowing network operator(s) to dynamically choose between modes of operation depending on circumstances, such as network throughput and compatibility. The system further enables information collected at a network device to be processed at a locate server without involving any processing at the network device.

The disclosure relates in some aspects to providing miniature power-efficient agile photonic generators of microwave waveforms. Illustrative examples use chip lasers integrated in close thermal proximity with one another to provide a miniature microwave arbitrary waveform generator (AWG). Due to the small size of the lasers and the close integration, common ambient fluctuations from the environment or other sources can be efficiently reduced, yielding improved spectral purity of generated radio-frequency (RF) signals. Tight physical integration also permits a small device footprint with minimal acceleration sensitivity. The lasers may be locked to cavities or other resonators to allow efficient decoupling of the frequency and amplitude modulation of the lasers to provide flexibility to the waveform generator. Exemplary devices described herein can produce frequency chirped signals for radar applications. The frequency chirp may be linear and/or nonlinear. Tuning methods are also described herein.

A method for creating a virtual reception channel in a radar system includes an antenna possessing two physical reception channels (1.sub.r, 2.sub.r) spaced apart by a distance d in a direction x, two emission channels (1.sub.e, 2.sub.e) spaced apart by the same distance d in the same direction x and processing means, the method comprising: dynamically selecting two different waveforms, the waveforms being orthogonal to each other; generating a radar pulse of given central wavelength in each emission channel, each of the emission channels emitting one of the two different waveforms; acquiring with the reception channels echoes due to pulses emitted by the emission channels and reflected by at least one target; compressing the pulses by matched filtering of the echoes acquired by each physical reception channel, this involving correlating them with each of the waveforms generated in the emission channel; and repeating steps a) to c) while randomly changing one of the values of each of the phase codes associated with the generated waveforms until the level of the sidelobes of all the compressed pulses has stabilized; and radar system for implementing such a method.

A method for creating a virtual reception channel in a radar system includes an antenna possessing two physical reception channels (1.sub.r, 2.sub.r) spaced apart by a distance d in a direction x, two emission channels (1.sub.e, 2.sub.e) spaced apart by the same distance d in the same direction x and processing means, the method comprising: dynamically selecting two different waveforms, the waveforms being orthogonal to each other; generating a radar pulse of given central wavelength in each emission channel, each of the emission channels emitting one of the two different waveforms; acquiring with the reception channels echoes due to pulses emitted by the emission channels and reflected by at least one target; compressing the pulses by matched filtering of the echoes acquired by each physical reception channel, this involving correlating them with each of the waveforms generated in the emission channel; and repeating steps a) to c) while randomly changing one of the values of each of the phase codes associated with the generated waveforms until the level of the sidelobes of all the compressed pulses has stabilized; and radar system for implementing such a method.

A synthetic aperture radar (SAR) is operable in an interrogation mode and in an imaging mode, the imaging mode entered in response to determining a response to interrogation pulses have been received from a ground terminal and position information specifying a ground location has been received from the ground terminal. A ground terminal is operable to receive interrogation pulses transmitted by a SAR, transmit responses, and transmit position information to cause the SAR to enter a imaging mode. The ground terminal receives first and subsequent pulses from the SAR where subsequent pulses include backscatter and are encoded. The ground terminal generates a range line by range compression. If the SAR is a multi-band SAR the transmitted pulses can be in two or more frequency bands, and subsequent pulses in one frequency band can include encoded returns from pulses transmitted in a different frequency band.

Space-time-frequency multiplexing (STFM) schemes for radio frequency (RF) scanning are disclosed in which complementary pairs of sequences (or Golay pairs) are transmitted at different times using multiple frequencies. The transmission and reception of the sequences can occur over multiple transmit (Tx) and/or receive (Rx) radio sectors to scan an entire area for range, azimuth, elevation, and (optionally) velocity of objects therein.

A pseudo low intermediate frequency (IF) configuration is provided for a receiver having a zero IF radio architecture dedicated for radar detection, in order to reduce false radar detection. Energy from local oscillator leakage is shifted away from DC. After filtering out of the desired sub-channel, the local oscillator leakage energy is suppressed, reducing false radar detection.