Disclosed herein are embodiments of high Q, temperature stable materials with low dielectric constants. In one aspect, a low loss dielectric material includes one or more transition metal oxides based on the (Zn, Ni, Co)O—Al.sub.2O.sub.3—TiO.sub.2 system comprising an aluminate comprising one of cobalt (Co) or nickel (Ni) crystallized in a spinel structure. The low loss dielectric material additionally comprises one or more of: a titanate comprising the one of Co or Ni crystallized in a spinel structure, an aluminum oxide and a titanium oxide crystallized in a rutile structure.

Disclosed are embodiments of synthetic garnet materials for use in radiofrequency applications. In some embodiments, increased amounts of gadolinium can be added into specific sites in the crystal structure of the synthetic garnet by incorporating indium, a trivalent element. By including both indium and increased amounts of gadolinium, the dielectric constant can be improved. Thus, embodiments of the disclosed material can be advantageous in both above and below resonance applications, such as for isolators and circulators.

A circuit comprising a differential transmission line and eight switches provides non-reciprocal signal flow. In some embodiments, the circuit can be driven by four local oscillator signals using a boosting circuit. The circuit can be used to form a gyrator. The circuit can be used to form a circulator. The circuit can be used to form three-port circulator than can provide direction signal flow between a transmitter and an antenna and from the antenna to a receiver. The three-port circulator can be used to implement a full duplex transceiver that uses a single antenna for transmitting and receiving.

A non-reciprocal quantum device that comprises a first terminal and a second terminal, a transmission structure connected between the first and second terminals and configured to transmit microscopic particles in at least a partially phase-coherent manner from the first terminal to the second terminal and possibly from the second terminal to the first terminal, wherein a time-reversal symmetry of the transmission of the particles is broken with respect to at least a portion of the transmission structure; wherein the time-reversal symmetry is broken in such a way that the transmission structure comprises a higher transmission probability for particles moving in a first direction from the first terminal to the second terminal than in a second direction from the second terminal to the first terminal.

A non-reciprocal quantum device that comprises a first terminal and a second terminal, a transmission structure connected between the first and second terminals and configured to transmit microscopic particles in at least a partially phase-coherent manner from the first terminal to the second terminal and possibly from the second terminal to the first terminal, wherein a time-reversal symmetry of the transmission of the particles is broken with respect to at least a portion of the transmission structure; wherein the time-reversal symmetry is broken in such a way that the transmission structure comprises a higher transmission probability for particles moving in a first direction from the first terminal to the second terminal than in a second direction from the second terminal to the first terminal.

The present invention discloses a low-field assembled isolator, which includes a rectangular body, wherein the body includes an upper cavity and a lower cavity which are connected in a stacked manner; gaps are formed in four side surfaces of the body through the joint surfaces of the upper cavity and the lower cavity respectively; and the isolator further includes a U-shaped magnetic circuit cover plate and two L-shaped magnetic circuit baffles; and the two L-shaped magnetic circuit baffles are respectively disposed at two corners, away from the vertical plate, of the body so as to seal the joint between two adjacent gaps. The gaps at the joint of the upper cavity and the lower cavity are effectively and fully sealed, thereby effectively preventing signal leakage and improving the performance of the low-field assembled isolator.

The present invention discloses a low-field assembled isolator, which includes a rectangular body, wherein the body includes an upper cavity and a lower cavity which are connected in a stacked manner; gaps are formed in four side surfaces of the body through the joint surfaces of the upper cavity and the lower cavity respectively; and the isolator further includes a U-shaped magnetic circuit cover plate and two L-shaped magnetic circuit baffles; and the two L-shaped magnetic circuit baffles are respectively disposed at two corners, away from the vertical plate, of the body so as to seal the joint between two adjacent gaps. The gaps at the joint of the upper cavity and the lower cavity are effectively and fully sealed, thereby effectively preventing signal leakage and improving the performance of the low-field assembled isolator.

An isolating circuit for electrosurgical generator arranged to produce radiofrequency (RF) energy and microwave energy for treating biological tissue. The generator has an RF channel and a microwave channel which are combined at signal combiner to enable the RF energy and microwave energy to be delivered into tissue along a common feed path. The isolating circuit comprises a tunable waveguide isolator at a junction between the microwave channel and signal combiner, and can include a capacitive structure between a ground conductor of the signal combiner and a conductive input section of the waveguide isolator to inhibit coupling of the RF energy and leakage of the microwave energy. The isolating circuit can combine into a single tunable unit all the necessary components to isolate the microwave and RF channels from one another whilst providing a high withstanding voltage.

An isolating circuit for electrosurgical generator arranged to produce radiofrequency (RF) energy and microwave energy for treating biological tissue. The generator has an RF channel and a microwave channel which are combined at signal combiner to enable the RF energy and microwave energy to be delivered into tissue along a common feed path. The isolating circuit comprises a tunable waveguide isolator at a junction between the microwave channel and signal combiner, and can include a capacitive structure between a ground conductor of the signal combiner and a conductive input section of the waveguide isolator to inhibit coupling of the RF energy and leakage of the microwave energy. The isolating circuit can combine into a single tunable unit all the necessary components to isolate the microwave and RF channels from one another whilst providing a high withstanding voltage.

Disclosed herein are embodiments of low temperature co-fireable scheelite materials which can be used in combination with high dielectric materials, such as nickel zinc ferrite, to form composite structures, in particular for isolators and circulators for radiofrequency components. In some embodiments, the scheelite material can include aluminum oxide for temperature expansion regulation.