In an embodiment, an apparatus included in a communications system includes a transmit section including a first baseband section and a first radio frequency (RF) section, wherein the transmit section is configured to receive a calibration signal, the first RF section is configured to generate a RF calibration signal based on the calibration signal, and wherein the calibration signal comprises an orthogonal code based signal; and a receive section configured to receive the RF calibration signal over-the-air, wherein the receive section includes a second RF section and a calibration section, wherein the second RF section is configured to generate a received calibration signal based on the RF calibration signal, and wherein the calibration section is configured to determine one or more of gain, baseband delay, or RF delay compensation values, based on the inputs, to calibrate the transmit section.

Methods, systems, computer-readable media, and apparatuses for determining one or more attributes of at least one target based on eigenspace analysis of radar signals are presented. In some embodiments, a subset of eigenvectors to use for forming a signal or noise subspace is identified based on principal component analysis. In some embodiments, the subset of eigenvectors is identified based on estimating the total number of targets using a discrete Fourier transform (DFT) or other spectral analysis technique. In some embodiments, a DFT is used to identify areas of interest in which to perform eigenspace analysis. In some embodiments, a DFT is used to estimate one attribute of a target, and eigenspace analysis is performed to estimate a different attribute of the target, with the results being combined to generate a multi-dimensional representation of a field of view.

Methods, systems, computer-readable media, and apparatuses for determining one or more attributes of at least one target based on eigenspace analysis of radar signals are presented. In some embodiments, a subset of eigenvectors to use for forming a signal or noise subspace is identified based on principal component analysis. In some embodiments, the subset of eigenvectors is identified based on estimating the total number of targets using a discrete Fourier transform (DFT) or other spectral analysis technique. In some embodiments, a DFT is used to identify areas of interest in which to perform eigenspace analysis. In some embodiments, a DFT is used to estimate one attribute of a target, and eigenspace analysis is performed to estimate a different attribute of the target, with the results being combined to generate a multi-dimensional representation of a field of view.

In an embodiment, an apparatus includes a first integrated circuit (IC) chip configured to receive a timing signal and a reference clock signal; and a second IC chip configured to receive the timing signal and the reference clock signal. The first and second IC chips are configured to generate respective first and second reference time signals based on the timing signal and the reference clock signal. The first and second IC chips include a respective first phase lock loop (PLL) and second PLL. The first PLL and the second PLL are synchronized to each other based on the first reference time signal and the second reference time signal.

Methods and devices for streamlining phase and amplitude calibration and linearization in RF transceiver circuits including a plurality of switchable transmit and receive processing paths is presented. According to one aspect, switchable feedback paths are provided that can selectively feedback a portion of a transmitted RF signal or a test RF signal for use in the calibration. According to another aspect, the switchable feedback paths include combination of switches and couplers to selectively combine feedback from one or more of the switchable feedback paths. According to another aspect, the switchable feedback paths reuse portions of the receive paths of the plurality of switchable transmit and receive processing paths. The switchable feedback paths can be used to provide a combined feedback RF signal based on one or more transmitted RF signals that can be used as a digital pre-distortion feedback for linearization of the one or more transmitted RF signals.

Methods and devices for streamlining phase and amplitude calibration and linearization in RF transceiver circuits including a plurality of switchable transmit and receive processing paths is presented. According to one aspect, switchable feedback paths are provided that can selectively feedback a portion of a transmitted RF signal or a test RF signal for use in the calibration. According to another aspect, the switchable feedback paths include combination of switches and couplers to selectively combine feedback from one or more of the switchable feedback paths. According to another aspect, the switchable feedback paths reuse portions of the receive paths of the plurality of switchable transmit and receive processing paths. The switchable feedback paths can be used to provide a combined feedback RF signal based on one or more transmitted RF signals that can be used as a digital pre-distortion feedback for linearization of the one or more transmitted RF signals.

Described is an machine-readable storage media having instruction stored thereon, that when executed, cause one or more processors to perform an operation comprising: sequentially transmit, in a first mode, at least two first probe request messages in at least two beam steering directions, respectively, towards a device; and receive, from the device, at least two first probe response messages in response to transmitting the at least two first probe request messages.

Described is an machine-readable storage media having instruction stored thereon, that when executed, cause one or more processors to perform an operation comprising: sequentially transmit, in a first mode, at least two first probe request messages in at least two beam steering directions, respectively, towards a device; and receive, from the device, at least two first probe response messages in response to transmitting the at least two first probe request messages.

Parametric flat lenses, which are an alternative to conventional flat lenses, are described for performing near-field imaging and electronic beam scanning. These lenses can electronically direct the near or far fields, and in some cases even achieve a conversion gain. The lens incorporates a plurality of input and output antennas between which are a plurality of parametric mixers. The parametric mixers can be utilized as well to change phase relationships in accommodating different input pattern or directing the output in different ways. The disclosure also describes a proof of concept implementation using off the shelf components.

Parametric flat lenses, which are an alternative to conventional flat lenses, are described for performing near-field imaging and electronic beam scanning. These lenses can electronically direct the near or far fields, and in some cases even achieve a conversion gain. The lens incorporates a plurality of input and output antennas between which are a plurality of parametric mixers. The parametric mixers can be utilized as well to change phase relationships in accommodating different input pattern or directing the output in different ways. The disclosure also describes a proof of concept implementation using off the shelf components.