A non-reciprocal mode converting SIW includes a first straight SIW section, a second straight SIW section, and a curved SIW section coupling the first straight SIW section to the second straight SIW section. The curved SIW section included magnetic biasing at opposed corner regions. The magnetic biasing and a curvature of the curved SIW section causes: (i) a wave in a first transverse electric (TE) mode that propagates in a forward direction from the first straight section through the curved SIW section into the second straight SIW section to convert to a second TE mode, and (ii) a wave in the first TE mode that propagates in a reverse direction from the second straight SIW section through the curved SIW section into the first straight SIW section to maintain the first TE mode.

A non-reciprocal mode converting SIW includes a first straight SIW section, a second straight SIW section, and a curved SIW section coupling the first straight SIW section to the second straight SIW section. The curved SIW section included magnetic biasing at opposed corner regions. The magnetic biasing and a curvature of the curved SIW section causes: (i) a wave in a first transverse electric (TE) mode that propagates in a forward direction from the first straight section through the curved SIW section into the second straight SIW section to convert to a second TE mode, and (ii) a wave in the first TE mode that propagates in a reverse direction from the second straight SIW section through the curved SIW section into the first straight SIW section to maintain the first TE mode.

A wide band radio frequency (RF) circulator is provided. The circulator includes a first stage having four ports; and a second stage having four ports, wherein the first stage and the second stage are connected via a pair of reciprocal delay lines, and wherein each of the first stage and the second stage includes a pair of couplers.

A wide band radio frequency (RF) circulator is provided. The circulator includes a first stage having four ports; and a second stage having four ports, wherein the first stage and the second stage are connected via a pair of reciprocal delay lines, and wherein each of the first stage and the second stage includes a pair of couplers.

A non-reciprocal mode converting SIW includes a first straight SIW section, a second straight SIW section, and a curved SIW section coupling the first straight SIW section to the second straight SIW section. The curved SIW section included magnetic biasing at opposed corner regions. The magnetic biasing and a curvature of the curved SIW section causes: (i) a wave in a first transverse electric (TE) mode that propagates in a forward direction from the first straight section through the curved SIW section into the second straight SIW section to convert to a second TE mode, and (ii) a wave in the first TE mode that propagates in a reverse direction from the second straight SIW section through the curved SIW section into the first straight SIW section to maintain the first TE mode.

A non-reciprocal mode converting SIW includes a first straight SIW section, a second straight SIW section, and a curved SIW section coupling the first straight SIW section to the second straight SIW section. The curved SIW section included magnetic biasing at opposed corner regions. The magnetic biasing and a curvature of the curved SIW section causes: (i) a wave in a first transverse electric (TE) mode that propagates in a forward direction from the first straight section through the curved SIW section into the second straight SIW section to convert to a second TE mode, and (ii) a wave in the first TE mode that propagates in a reverse direction from the second straight SIW section through the curved SIW section into the first straight SIW section to maintain the first TE mode.

In accordance with some embodiments, non-reciprocal circulators are provided, the circulators comprising: a 3X/4-long ring section having a first end and a second end, wherein is an operating wavelength of the non-reciprocal circulator; and a N-path filter having a first port, a second port, and N-paths, each of the N-paths being connected to the first port and the second port. In some of these embodiments, the 3/4-long ring section includes a transmit port, an antenna port, and a receive port. In some of these embodiments, the transmit port is /4 away from the antenna port. In some of these embodiments, the antenna port is /4 away from the receive port. In some of these embodiments, the receive port is at the first port of the N-path filter.

In accordance with some embodiments, non-reciprocal circulators are provided, the circulators comprising: a 3X/4-long ring section having a first end and a second end, wherein is an operating wavelength of the non-reciprocal circulator; and a N-path filter having a first port, a second port, and N-paths, each of the N-paths being connected to the first port and the second port. In some of these embodiments, the 3/4-long ring section includes a transmit port, an antenna port, and a receive port. In some of these embodiments, the transmit port is /4 away from the antenna port. In some of these embodiments, the antenna port is /4 away from the receive port. In some of these embodiments, the receive port is at the first port of the N-path filter.

A microwave circulator including an integrated circuit and having a number of ports, a respective superconducting ring segment coupled to each port to allow microwave frequency signals to be transferred between the port and the respective ring segment, a superconducting tunnel junction interconnecting each pair of adjacent ring segments to form a circulator ring, wherein the tunnel junctions are configured so that when a bias is applied to the tunnel junctions, signals undergo a phase shift as they traverse the tunnel junctions between ring segments, thereby propagating signals to an adjacent port in a propagation direction and at least one feature to at least partially suppress quasiparticles within the circulator.

A microwave circulator including an integrated circuit and having a number of ports, a respective superconducting ring segment coupled to each port to allow microwave frequency signals to be transferred between the port and the respective ring segment, a superconducting tunnel junction interconnecting each pair of adjacent ring segments to form a circulator ring, wherein the tunnel junctions are configured so that when a bias is applied to the tunnel junctions, signals undergo a phase shift as they traverse the tunnel junctions between ring segments, thereby propagating signals to an adjacent port in a propagation direction and at least one feature to at least partially suppress quasiparticles within the circulator.