A hybrid coupler operating in a power divider mode includes two inputs, two outputs, a capacitive module coupled between the inputs and the outputs or on each input and each output. The capacitive module has an adjustable capacitive value making it possible to adjust the central frequency. A calibration method includes: delivering a first reference signal having a first reference frequency on the first input of the hybrid coupler, measuring the peak value of a first signal delivered to the first output of the coupler and measuring the peak value of a second signal delivered to the second output of the coupler. The two peak values are compared and an adjustment of the capacitive value of the capacitive module is made until an equality of the peak values is obtained to within a tolerance.

Embodiments of this application disclose a signal processing circuit, a radio frequency signal transmitter, and a communications device, and relate to the field of electronic device technologies, to improve power amplification efficiency of the signal processing circuit. The signal processing circuit includes: a splitter, a radio frequency signal converter, a first branch power amplifier, a second branch power amplifier, and a combiner. The splitter is connected to the radio frequency signal converter, the radio frequency signal converter is connected to the first branch power amplifier and the second branch power amplifier, and the first branch power amplifier and the second branch power amplifier are connected to the combiner.

Embodiments of this application disclose a signal processing circuit, a radio frequency signal transmitter, and a communications device, and relate to the field of electronic device technologies, to improve power amplification efficiency of the signal processing circuit. The signal processing circuit includes: a splitter, a radio frequency signal converter, a first branch power amplifier, a second branch power amplifier, and a combiner. The splitter is connected to the radio frequency signal converter, the radio frequency signal converter is connected to the first branch power amplifier and the second branch power amplifier, and the first branch power amplifier and the second branch power amplifier are connected to the combiner.

Disclosed is a quasi-circulator using an asymmetric directional coupler. The quasi-circulator using the asymmetric directional coupler according to an embodiment of the present invention may enhance a characteristic of isolating a transmitting signal from a receiving signal with the same characteristic as transmitting signal loss of a symmetric directional coupler in the related art by arranging impedance of each line of a directional coupler asymmetrically.

A device and a method for creating and/or maintaining an obstruction free upper respiratory passages. The device is configured to fit under the chin of a subject adjacent to the subject's neck at an external location corresponding approximately with the subject's internal soft tissue associated with the neck's anterior triangle. The device is capable of exerting negative pressure on the surface of a subject's neck, displacing the soft tissue forward and enlarging the airway.

The present application discloses embodiments that relate to an electromagnetic apparatus. In one aspect, the present apparatus includes a circuit board configured to propagate an electromagnetic signal. The apparatus also includes a waveguide configured to propagate an electromagnetic signal. The apparatus further includes a coupling port configured to couple a signal between the circuit board and the waveguide, where the coupling port has dimensions based on a desired impedance of the port.

A branch line directional coupler has a first line, a second line, a first open-ended coupled circuit, and a second open-ended coupled circuit. The first and second lines have a first characteristic impedance and a quarter wavelength length. The first open-ended coupled line has one end connected to the first line and the other end connected to the second line. The second open-ended coupled line has one end connected to the first line and the other end connected to the second line. The first open-ended coupled line has two coupled lines having a coupling length of a quarter wavelength, an open stub, and a connecting line, and has a total length of one-half wavelength. The second open-ended coupled line includes two coupled lines having a coupling length of -wavelength, open stubs, and a connecting line, and has a total length of -wavelength.

A branch line directional coupler has a first line, a second line, a first open-ended coupled circuit, and a second open-ended coupled circuit. The first and second lines have a first characteristic impedance and a quarter wavelength length. The first open-ended coupled line has one end connected to the first line and the other end connected to the second line. The second open-ended coupled line has one end connected to the first line and the other end connected to the second line. The first open-ended coupled line has two coupled lines having a coupling length of a quarter wavelength, an open stub, and a connecting line, and has a total length of one-half wavelength. The second open-ended coupled line includes two coupled lines having a coupling length of -wavelength, open stubs, and a connecting line, and has a total length of -wavelength.

A full duplex communication system comprises a magnet-less ring circulator that comprises a set of ports extending from a circumference of the magnet-less multi-port ring combiner. The set of ports are positioned at increments around the circumference of the magnet-less multi-port ring combiner.

The disclosed systems, structures, and methods are directed to an orbital angular momentum (OAM) receiver. The OAM receiver includes at least two receiver antenna elements to receive radiated OAM signal beams containing superposed order modes and to generate antenna element output signals based on the received OAM signal beams. The receiver antenna elements are positioned tangentially along a circular locus and spatially separated by a distance. A variable ratio combining unit operates to switch between the antenna output signals based on a high-rate periodic waveform that emulates unidirectional movement by the antenna elements to produce a pseudo-Doppler frequency shift. The variable ratio combining unit further modulates the antenna output signals based on the periodic waveform to impart a fractional pseudo-Doppler shift to each OAM mode and combines the modulated antenna element output signals in accordance with the fractional pseudo-Doppler shift to facilitate separation of the OAM modes.