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.

A multiport microwave device includes a first reactive three-port microwave device, a second reactive three-port microwave device, a third reactive three-port microwave device, and a matched four-port microwave device. The four-port microwave device includes first and second input ports and first and second output ports communicatively coupled to one another. A first port of each of the first, second and third three-port microwave devices is operative to receive a microwave signal, and a first output port and a second output port of the four-port microwave device are each operative to output a microwave signal. A second port of the first microwave device is communicatively coupled to a second port of the second microwave device, a second port of the third microwave device is communicatively coupled to a third port of the second microwave device, and a third port of the first microwave device is communicatively coupled to the first input port the four-port microwave device. A third port of the third microwave device is communicatively coupled to the second input port of the four-port microwave device.

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 polarization waveguide network includes a reactive transmit (TX) power splitter and multiple receive (RX)-reject waveguide filters to reject RX frequencies. The polarization waveguide network further includes a quadrature junction coupler that can couple the RX-reject waveguide filters to an antenna port. The polarization waveguide network is configured to be fabricated in three pieces with two zero-current split planes, and a first piece of the three pieces is used for coupling to the antenna port.

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 small-scale branch-line coupler suitable for use in mobile devices includes a first, second, third, and fourth ports, respectively acting as input, transmission, coupled, and isolated ports. A first, second, third, and fourth connection parts are connected to the ports and transmission lines. First angular transmission lines are between first and second ports, third angular transmission lines are between third and fourth ports. A third long strip transmission line connects the first port and the fourth port. A fourth long strip transmission line connects the second port and the third port. The branch-line coupler occupies a small area and has high performance.

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.

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 Doherty power amplifier and a device are disclosed. In a combiner of the Doherty power amplifier, a first input port and a termination port are open coupled by at least two coupled microstrip lines and/or a second input port and an output port are open coupled by at least two coupled microstrip lines. Therefore, a balanced amplitude bandwidth may be obtained and may be much broader than that of the existing solutions, in addition, a controllable size or a potentially small size may be realized. Furthermore, the Doherty power amplifier in this disclosure may provide large 2.sup.nd harmonic suppression to meet product spectrum mask requirements.