Aspects of the of the disclosure relate to a non-contact physiological motion sensor and a monitor device that can incorporate use of the Doppler effect. A continuous wave of electromagnetic radiation can be transmitted toward one or more subjects and the Doppler-shifted received signals can be digitized and/or processed subsequently to extract information related to the cardiopulmonary motion in the one or more subjects. The extracted information can be used, for example, to determine apneic events and/or snoring events and/or to provide apnea or snoring therapy to subjects when used in conjunction with an apnea or snoring therapy device. In addition, methods of use are disclosed for sway cancellation, realization of cessation of breath, integration with multi-parameter patient monitoring systems, providing positive providing patient identification, or any combination thereof.

A distance measuring device according to an embodiment includes a filter, a first switching circuit, an impedance adjustable circuit, a second switching circuit, a third switching circuit, and a fourth switching circuit. The filter restricts a signal for distance measurement transmitted from the transmission circuit and a signal for distance measurement received by an antenna within a desired frequency band. The impedance adjustable circuit is adjusted to have a higher impedance than an impedance of the antenna. The second switching circuit switches conduction and non-conduction between the impedance adjustable circuit and the transmission circuit. The third switching circuit switches conduction and non-conduction between the impedance adjustable circuit and the reception circuit. The fourth switching circuit switches conduction and non-conduction between the impedance adjustable circuit and the second switching circuit and between the impedance adjustable circuit and the third switching circuit.

A frequency modulated continuous wave radar system includes at least one identity tag, respectively disposed next to at least one test subject; and a frequency modulated continuous wave radar identity recognition device, including an identity recognition control module, for controlling a test identity tag of the at least one identity tag to be turned on to generate a specific tag reflection signal corresponding to an identity frequency in response to a chirp signal; and a frequency modulated continuous wave radar, for transmitting the chirp signal and receiving at least one reflection signal of the at least one test subject and the specific tag reflection signal in response to the chirp signal, to calculate and determine that the specific tag reflection signal and a specific reflection signal of the at least one reflection signal are corresponding to an adjacent position information. The specific reflection signal is corresponding to test subject information.

A launch monitor for golf training includes both a continuous wave radar transmitter and a frequency modulated continuous wave radar transmitter. A first set of golf ball trajectory parameters are estimated with the continuous wave radar transmitter and a second, different set of golf ball trajectory parameters are estimated with the frequency modulated continuous wave radar transmitter. The array of transmitters and receivers may be non-uniform.

A launch monitor for golf training includes both a continuous wave radar transmitter and a frequency modulated continuous wave radar transmitter. A first set of golf ball trajectory parameters are estimated with the continuous wave radar transmitter and a second, different set of golf ball trajectory parameters are estimated with the frequency modulated continuous wave radar transmitter. The array of transmitters and receivers may be non-uniform.

A radio frequency identification (RFID) system includes an array of antennas to distinguish line-of-sight (LOS) paths from non-line-of-sight (NLOS) paths. The distance between adjacent antennas in the array of antennas is less than half the wavelength of the radio frequency (RF) signal of the system. Each antenna in the antenna array is also digitally controlled to change relative phase difference among the antennas, thereby allowing digital steering of the array of antennas across angles of arrival (AOAs) between 0 and π. The digital steering generates a plot of signal amplitudes as a function of AOAs. LOS paths are distinguished from NLOS paths based on the shapes (e.g., depth, gradient, etc.) of local extremes (e.g., maxima or minima) in the plot.

A system is disclosed for locating a device (15) in a ducting system comprising a conduit (100) and a shaft (140) arranged next to or above the conduit (100), the system comprising a base station (12) of a radar system (10) with a transmitter (22) and a receiver (19) and a signal source (21) for a clock signal (1) that can be sent by means of the transmitter (22) of the base station (12), the system also comprising a transponder (14), which is arranged on a mobile device (15) and is designed and configured to receive and to modulate the clock signal (1) and to send the modulated clock signal (1) back to the receiver (19) of the base station (1) as a locating signal. A fastening means (150) is also included and is fastened in the shaft, the fastening means (150) comprising a boom (160) extending in front of an opening region of the conduit (100), and the transmitter (22) and the receiver (19) being arranged on the boom.

A system is disclosed for locating a device (15) in a ducting system comprising a conduit (100) and a shaft (140) arranged next to or above the conduit (100), the system comprising a base station (12) of a radar system (10) with a transmitter (22) and a receiver (19) and a signal source (21) for a clock signal (1) that can be sent by means of the transmitter (22) of the base station (12), the system also comprising a transponder (14), which is arranged on a mobile device (15) and is designed and configured to receive and to modulate the clock signal (1) and to send the modulated clock signal (1) back to the receiver (19) of the base station (1) as a locating signal. A fastening means (150) is also included and is fastened in the shaft, the fastening means (150) comprising a boom (160) extending in front of an opening region of the conduit (100), and the transmitter (22) and the receiver (19) being arranged on the boom.

A method of operating a frequency modulated continuous-wave radar can include transmitting CHIRP signals from a plurality of antennas of the frequency modulated continuous-wave radar, receiving, via the plurality of antennas, signals including asynchronously modulated retro-directive signals from at least one remote radio frequency tag generated responsive to the CHIRP signals, generating difference Intermediate Frequency signals from the CHIRP signals transmitted and the signals received, and performing a first transform operation on the difference Intermediate Frequency signals to detect occurrence of the asynchronously modulated retro-directive signals in the difference Intermediate Frequency signals.

A method of operating a frequency modulated continuous-wave radar can include transmitting CHIRP signals from a plurality of antennas of the frequency modulated continuous-wave radar, receiving, via the plurality of antennas, signals including asynchronously modulated retro-directive signals from at least one remote radio frequency tag generated responsive to the CHIRP signals, generating difference Intermediate Frequency signals from the CHIRP signals transmitted and the signals received, and performing a first transform operation on the difference Intermediate Frequency signals to detect occurrence of the asynchronously modulated retro-directive signals in the difference Intermediate Frequency signals.