Embodiments of the disclosure include a Radio Detection and Ranging (Radar) system with reduced transmitter antenna and receiver antenna mutual coupling. The radar system includes a transmitter antenna disposed on a first side of the dielectric substrate and a receiver antenna disposed on the same side of the dielectric substrate. The radiation boundaries of the transmitter antenna and the receiver antenna are substantially parallel to a line connecting centroids of the transmitter antenna and the receiver antenna. The radar system also includes a ground plane disposed on a second side of the dielectric substrate, opposite to the first side, operatively connected to the transmitter antenna and the receiver antenna through probes. The ground plane comprises at least one groove, separating vertical projections of the transmitter antenna and the receiver antenna on the ground plane.

A radio wave reflection reducing sheet provided with a laminate having a first primary surface and a second primary surface is disclosed. The laminate has: a first resin foam layer having a thickness from 0.05 to 3.00 mm and a density from 0.10 to 0.85 g/cm.sup.3, and a second resin foam layer having a thickness from 0.05 to 3.00 mm and a density from 0.20 to 0.90 g/cm.sup.3. The density of the second resin foam layer is greater than the density of the first resin foam layer. The first resin foam layer and the second resin foam layer are disposed in this order from the first primary surface side.

A full duplex radio apparatus comprising: a transmit path configured to transmit a first signal; a receive path configured to receive a received signal; a near-receive path for observing a first period of the received signal; a far-receive path for observing a second period of the received signal, the far-receive path comprising a radio frequency limiter; a self-interference cancellation circuit coupled between the transmit path and the near receive path; a variable impedance component; and a directional coupler comprising a first port, a second port, a third port, and a fourth port, wherein: the first port is coupled to the receive path; the second port is coupled to the radio frequency limiter of the far-receive path; the third port is coupled to the self-interference cancellation circuit; and the fourth port is coupled to the variable impedance component.

A radar system may include a set of analog components to perform one or more radio frequency (RF) operations during an active radar phase of the radar system. The radar system may include a set of digital components to perform one or more digital processing operations during at least a digital processing phase of the radar system. The one or more digital processing operations may be performed such that performance of the one or more digital processing operations does not overlap performance of a substantive portion of the one or more RF operations.

A method and electronic device for object detection. The electronic device includes at least a first antenna pair comprising a first transmitter antenna configured to transmit signals and a first receiver antenna configured to receive signals, a memory, and a processor. The processor is configured to control the first transmitter antenna to transmit a first signal, generate a channel impulse response (CIR) based on receiving, by the first receiver antenna, a reflection of the first signal, determine a location of at least one leakage peak in the CIR, compare a first segment of taps in the CIR prior to the at least one leakage peak with a second segment of taps in the CIR after the leakage peak, and determine an object is present based on symmetry between the first and second segments of taps.

This document describes techniques, apparatuses, and systems for a wave-shaped ground structure for antenna arrays. A radar system may include a ground structure with a first surface having a wave shape and a second surface opposite the first surface. The ground structure includes multiple antenna arrays separated in a longitudinal direction on the first surface. Each antenna array includes one or more antenna elements configured to emit or receive electromagnetic (EM) energy. The ground structure also includes antenna feeds separated in the longitudinal direction on the second surface and operably connected to the antenna arrays. The wave shape of the ground structure configures the radar system to provide an antenna radiation pattern that provides a uniform radiation pattern among the antenna arrays. The wave shape can also be configured to provide an asymmetrical radiation pattern or a narrow beamwidth for specific applications.

The present disclosure relates to adjusting a suppression signal for suppressing a radio frequency (RF) interference signal in a received signal. A method includes generating an RF signal having a first frequency offset from an interference frequency; generating the suppression signal having a second frequency offset from the interference frequency; coupling the suppression signal into the received signal in order to generate a receiver input signal; mixing the receiver input signal with the RF signal in order to generate a mixer output signal; adjusting an amplitude of the suppression signal in order to align amplitudes of different components of the mixer output signal; coupling an adjusted suppression signal, having the interference frequency and the adjusted amplitude, into the received signal; and varying a phase of the adjusted suppression signal in order to reduce a frequency component of the mixer output signal that has the first frequency offset.

A method for close-range detection, includes transmitting, via a radar transceiver, radar signals to detect an object. The method also includes determining whether the object includes a pattern code based on reflections of the radar signals received by the radar transceiver. In response to determining that the object includes the pattern code, the method includes identifying range information about a range between the electronic device and the pattern code. The method further includes selecting, based on the range information, one or more signals from the reflections of the radar signals that are reflected off of the pattern code. Additionally, the method includes identifying, based on the one or more signals, information about the pattern code.

In some aspects, a radar device may receive a received signal comprising a reflected frequency modulated continuous wave (FMCW) radar signal and interference. The radar device may identify the reflected FMCW radar signal based at least in part on performing a phase based search procedure to facilitate removing the interference from the received signal. The radar device may perform an action based at least in part on a characteristic of the identified reflected FMCW radar signal. Numerous other aspects are described.

An electronic device may include wireless circuitry with a transmit antenna that transmits signals and a receive antenna that receives reflected signals. The wireless circuitry may detect a range between the device and an external object based on the transmitted signals and the reflected signals. When the range exceeds a first threshold, the wireless circuitry may use the transmitted signals and received signals to record background noise. When the range is less than a second threshold value, the wireless circuitry may detect the range based on the reflected signals and the recorded background noise. This may allow the range to be accurately measured within an ultra-short range domain even when the device is placed in different device cases, placed on different surfaces, etc.