An electronic device may include isolation circuitry coupled between a transmitter, a receiver, and one or more antennas. The isolation circuitry may include a 90 degree hybrid coupler configured receive a transmission (TX) signal from the transmitter, split the TX signal into a first portion and a second portion, and phase-shift a portion such that the portions are +90 degrees out-of-phase. The isolation circuitry may include phase shifters that phase-shift the portions such that the portions are in-phase prior to propagating to the antenna. The phase shifters may receive a first portion and a second portion of a receiver (RX) signal from splitter circuitry. The phase shifters may phase-shift the portions such that the portions are out-of-phase by ?90 degrees. The 90 degree hybrid coupler may phase-shift the first portion and/or the second portion such that the portions are in-phase and constructively combine prior to propagating to the receiver.

An antenna device is formed by arranging radiation elements each radiating a circularly polarized wave in a matrix of three rows and four columns. The radiation elements include three sets of radiation elements of four types having a positional relationship rotationally symmetric with each other. The radiation elements are arranged such that adjacent elements are of different types.

A coupled-line rat-race coupler includes four ports and four coupled-lines each composed of two metal lines. Two of the ports are respectively connected with the front ends of the two lines of the first coupled-line, and the other two ports are respectively connected with the front ends of the two lines of the second coupled-line. The two lines of the third coupled-line are short circuited and respectively connected with the back end of one line of the first coupled-line on one side and with the back end of one line of the second coupled-line on the other side. In the fourth coupled-line, one line is open at one end and short circuited at the other end with the other line, which is connected with one line of the first coupled-line and one line of the second coupled-line. The coupled-line rat-race coupler is characterized with smooth and stable output phase.

A duplexer includes a 90 hybrid connected to an antenna terminal, a 90 hybrid connected to a terminating resistor, a transmission-side filter connected to the 90 hybrid connected to the antenna terminal, and notch filters connected to both of the 90 hybrids and mutually having the same filter characteristics, where each of the notch filters is a band elimination filter configured to reflect a radio frequency signal of a transmission band and allow a radio frequency signal of a band other than the transmission band to pass through.

A phase shifter device is disclosed and comprises a continuous transmission line on a substrate, and a plurality of ports coupled to the continuous transmission line and spaced apart from each other around the continuous transmission line. The plurality of ports comprises a first port, a second port, a third port, a fourth port, and a fifth port. A radio frequency (RF) switch is operative to connect either the first port or the fifth port to a main RF line that is coupled to one or more antennas. The second port is located between the first port and the third port, and the fourth port is located between the fifth port and the third port. In an alternative embodiment, the phase shifter device is combined with a circular polarization quadrature divider.

To provide an optical 90-degree hybrid formed of a silicon waveguide capable of suppressing an optical loss and a phase error, and facilitating electronic packaging and optical packaging. In the optical 90-degree hybrid circuit including two optical branching units facing each other and two optical coupling units facing away from each other, four arm waveguides are arranged including bent waveguides each of which guides an output light of the optical branching unit to the optical coupling unit, and is formed in a curved shape.

A technique relates to a lossless multiport device. The lossless multiport device includes a first port. A plurality of ports are operable to communicatively couple one at a time to the first port according to a pump drive.

A technique relates to a lossless multiport device. The lossless multiport device includes a first port. A plurality of ports are operable to communicatively couple one at a time to the first port according to a pump drive.

Circuits for wireless communication on multiple frequency bands are provided. In accordance with some embodiments, transceivers are provided, the transceivers comprising: a first quadrature hybrid having a first in port, a first iso port, a first cpl port, and a first thru port; an antenna coupled to the first in port; a first transmitter having an output coupled to the first cpl port; and a first receiver having an input coupled to the first cpl port.

An annual directional coupler having at least three taps, which are each arranged relative to one another around routes having a wavelength difference of of a wave guide wavelength, includes in particular at least two branch lines, wherein a first branch line has at least three taps and wherein the at least second branch line does not have any taps and is supplemented by an additional route corresponding to the wave guide wavelength.