A differential transmission line having a switch may comprise: a first transmission line comprising a first distribution element having a first impedance; a second transmission line comprising a second distribution element having a second impedance; and a first switch block connected between a first end of the first transmission line and a first end of the second transmission line, wherein the first switch block comprises a first switch connected in series to the first end of the first transmission line, a second switch connected in series to the first end of the second transmission line, a first-cross capacitor connected between a first terminal of the first switch and a second terminal of the second switch, and a second cross-capacitor connected between a first terminal of the second switch and a second terminal of the first switch.

A differential transmission line having a switch may comprise: a first transmission line comprising a first distribution element having a first impedance; a second transmission line comprising a second distribution element having a second impedance; and a first switch block connected between a first end of the first transmission line and a first end of the second transmission line, wherein the first switch block comprises a first switch connected in series to the first end of the first transmission line, a second switch connected in series to the first end of the second transmission line, a first-cross capacitor connected between a first terminal of the first switch and a second terminal of the second switch, and a second cross-capacitor connected between a first terminal of the second switch and a second terminal of the first switch.

A differential circulator comprises first and second magnets, a ground plane, a first three-port junction conductor disposed between the first magnet and the ground plane, and a second three-port junction conductor disposed between the second magnet and the ground plane. The first three-port junction conductor and the second three-port junction conductor are in the same magnetic circuit including the first and second magnets to provide substantially same pass characteristics to radio frequency signals passing through the first three-port junction conductor and the second three-port junction conductor.

A circulator comprising a grounding plane including a first side and a second side, a magnet disposed on the first side of the grounding plane, a ferrite-based disk disposed on the second side of the grounding plane, and a conductor disposed on a side of the ferrite-based disk opposing the grounding plane. The conductor includes an elongate portion and the elongate portion has a distal end section projecting inwardly adjacent to a side of the magnet opposing the grounding plane. The circulator comprises a circulator housing including a plurality of side portions. The side portions have a first section and a second section, the second section extending further around a periphery of the housing than the first section such that a gap between neighboring first sections is wider than a gap between neighboring second sections.

A circulator comprising a grounding plane including a first side and a second side, a magnet disposed on the first side of the grounding plane, a ferrite-based disk disposed on the second side of the grounding plane, and a conductor disposed on a side of the ferrite-based disk opposing the grounding plane. The conductor includes an elongate portion and the elongate portion has a distal end section projecting inwardly adjacent to a side of the magnet opposing the grounding plane. The circulator comprises a circulator housing including a plurality of side portions. The side portions have a first section and a second section, the second section extending further around a periphery of the housing than the first section such that a gap between neighboring first sections is wider than a gap between neighboring second sections.

A circulator includes: a ferrite plate; a permanent magnet that applies a direct current (DC) magnetic field to the ferrite plate; a first coil, a second coil, and a third coil arranged on the ferrite plate while being insulated from one another, the first coil, the second coil, and the third coil having coil axes intersecting one another; a first port that is electrically continuous with the first coil; a second port that is electrically continuous with the second coil; and a third port that is electrically continuous with the third coil. An inductance of the first coil or the second coil is different from an inductance of the third coil, and an impedance of the first port or the second port is not 50Ω.

A circulator includes: a ferrite plate; a permanent magnet that applies a direct current (DC) magnetic field to the ferrite plate; a first coil, a second coil, and a third coil arranged on the ferrite plate while being insulated from one another, the first coil, the second coil, and the third coil having coil axes intersecting one another; a first port that is electrically continuous with the first coil; a second port that is electrically continuous with the second coil; and a third port that is electrically continuous with the third coil. An inductance of the first coil or the second coil is different from an inductance of the third coil, and an impedance of the first port or the second port is not 50Ω.

Embodiments of the present invention provide an apparatus and a method for interference cancellation. The apparatus includes: a splitter, configured to acquire a first transmit signal and a second transmit signal; a first circulator, configured to transmit the first transmit signal to an antenna and to send a to-be-processed signal to a combiner, where the to-be-processed signal includes a receive signal component and a self-interference signal component, the self-interference signal component corresponds to an interference signal generated due to that the antenna reflects the first transmit signal; a second circulator, configured to: transmit the second transmit signal to an equivalent load, and acquire a reference signal generated due to that the equivalent load reflects the second transmit signal, where an impedance of the equivalent load corresponds to an impedance of the antenna; and a combiner, configured to cancel the self-interference signal component according to the reference signal.

Embodiments of the present invention provide an apparatus and a method for interference cancellation. The apparatus includes: a splitter, configured to acquire a first transmit signal and a second transmit signal; a first circulator, configured to transmit the first transmit signal to an antenna and to send a to-be-processed signal to a combiner, where the to-be-processed signal includes a receive signal component and a self-interference signal component, the self-interference signal component corresponds to an interference signal generated due to that the antenna reflects the first transmit signal; a second circulator, configured to: transmit the second transmit signal to an equivalent load, and acquire a reference signal generated due to that the equivalent load reflects the second transmit signal, where an impedance of the equivalent load corresponds to an impedance of the antenna; and a combiner, configured to cancel the self-interference signal component according to the reference signal.

A coaxial waveguide conversion device according to the present invention includes a first member; a second member provided so as to be opposed to the first member; and a conductor plate provided so as to be sandwiched between the first member and the second member. A waveguide is formed in the first member and the second member to a depth that penetrates the first member and does not penetrate the second member. The conductor plate includes an opening having a shape corresponding to a shape of an aperture plane of the waveguide; a conductor surface portion provided around the opening; an antenna portion; a waveguide short-circuit portion connecting the antenna portion with the conductor surface portion; a coaxial wiring portion provided at one end of the antenna portion; and a coaxial line short-circuit portion connecting another end of the antenna portion with the conductor surface portion.