A Wilkinson power combiner (202) is described that includes a high-pass, HP, frequency circuit (500, 550), wherein the HP frequency circuit (500, 550) comprises at least one of: (i) one input port (510) coupled to at least two output ports (512, 514) via at least two paths; and an input shunt inductor (520) coupling the input port (510) to ground; wherein the one input port (510) is coupled to the at least two output ports (512, 514) via respective series capacitances (230, 238) on the at least two paths, which in cooperation with the input shunt inductor (520) forms a first HP frequency circuit; and (ii) at least one resistor (554, 528)-inductor (552, 524), R-L isolation circuit (500, 550) configured to couple the at least two output ports (512, 514) that forms a second HP frequency circuit.

A Wilkinson power combiner (202) is described that includes a high-pass, HP, frequency circuit (500, 550), wherein the HP frequency circuit (500, 550) comprises at least one of: (i) one input port (510) coupled to at least two output ports (512, 514) via at least two paths; and an input shunt inductor (520) coupling the input port (510) to ground; wherein the one input port (510) is coupled to the at least two output ports (512, 514) via respective series capacitances (230, 238) on the at least two paths, which in cooperation with the input shunt inductor (520) forms a first HP frequency circuit; and (ii) at least one resistor (554, 528)-inductor (552, 524), R-L isolation circuit (500, 550) configured to couple the at least two output ports (512, 514) that forms a second HP frequency circuit.

An electrosurgical apparatus having a feed structure comprising a radiofrequency (RF) channel for conveying RF electromagnetic (EM) radiation from an RF signal generator to a probe and a microwave channel for conveying microwave EM radiation from a microwave signal generator to the probe, wherein the RF channel and microwave channel comprise physically separate signal pathways, wherein the feed structure includes a combining circuit having an input connected to the signal pathway on the RF channel, another input connected to the signal pathway on the microwave channel, and an output connected to a common signal pathway for conveying the RE EM radiation and EM radiation separately or simultaneously to the probe, and wherein the microwave channel includes a waveguide isolator connected to isolate the signal pathway on the microwave channel from the RF EM radiation.

An electrosurgical apparatus having a feed structure comprising a radiofrequency (RF) channel for conveying RF electromagnetic (EM) radiation from an RF signal generator to a probe and a microwave channel for conveying microwave EM radiation from a microwave signal generator to the probe, wherein the RF channel and microwave channel comprise physically separate signal pathways, wherein the feed structure includes a combining circuit having an input connected to the signal pathway on the RF channel, another input connected to the signal pathway on the microwave channel, and an output connected to a common signal pathway for conveying the RE EM radiation and EM radiation separately or simultaneously to the probe, and wherein the microwave channel includes a waveguide isolator connected to isolate the signal pathway on the microwave channel from the RF EM radiation.

A non-reciprocal microwave network is provided that includes an in-line ferromagnetic element [1010] with adjoining polarizing adapters [1002, 1004, 1006, 1008] to achieve directivity via a multi-mode interaction at or near the ferrite to act as new class of 4-port circulator or 2-port isolator, with standard waveguide inputs for assembly in larger networks.

A non-reciprocal circuit element includes a ferrite, a first central electrode and a second central electrode that are arranged on the ferrite so as to cross each other in an insulated state, and a permanent magnet configured to apply a DC magnetic field to a portion where the first and second central electrodes cross each other. One end of the first central electrode defines an input port and the other end thereof defines an output port. One end of the second central electrode defines the input port and the other end thereof defines a ground port. A resistance element and a capacitance element which are connected in parallel with each other are connected in series between the input port and the output port. A switching capacitance unit configured to switch a capacitance is connected in parallel with the resistance element between the input port and the output port.

A non-reciprocal circuit element includes a ferrite, a first central electrode and a second central electrode that are arranged on the ferrite so as to cross each other in an insulated state, and a permanent magnet configured to apply a DC magnetic field to a portion where the first and second central electrodes cross each other. One end of the first central electrode defines an input port and the other end thereof defines an output port. One end of the second central electrode defines the input port and the other end thereof defines a ground port. A resistance element and a capacitance element which are connected in parallel with each other are connected in series between the input port and the output port. A switching capacitance unit configured to switch a capacitance is connected in parallel with the resistance element between the input port and the output port.

A Wilkinson power combiner (202) is described that includes a high-pass, HP, frequency circuit (500, 550), wherein the HP frequency circuit (500, 550) comprises at least one of: (i) one input port (510) coupled to at least two output ports (512, 514) via at least two paths; and an input shunt inductor (520) coupling the input port (510) to ground; wherein the one input port (510) is coupled to the at least two output ports (512, 514) via respective series capacitances (230, 238) on the at least two paths, which in cooperation with the input shunt inductor (520) forms a first HP frequency circuit; and (ii) at least one resistor (554, 528)-inductor (552, 524), R-L isolation circuit (500, 550) configured to couple the at least two output ports (512, 514) that forms a second HP frequency circuit.

A Wilkinson power combiner (202) is described that includes a high-pass, HP, frequency circuit (500, 550), wherein the HP frequency circuit (500, 550) comprises at least one of: (i) one input port (510) coupled to at least two output ports (512, 514) via at least two paths; and an input shunt inductor (520) coupling the input port (510) to ground; wherein the one input port (510) is coupled to the at least two output ports (512, 514) via respective series capacitances (230, 238) on the at least two paths, which in cooperation with the input shunt inductor (520) forms a first HP frequency circuit; and (ii) at least one resistor (554, 528)-inductor (552, 524), R-L isolation circuit (500, 550) configured to couple the at least two output ports (512, 514) that forms a second HP frequency circuit.

Fabrication of superconducting devices that combine or separate direct currents and microwave signals is provided. A method can comprise forming a direct current circuit that supports a direct current, a microwave circuit that supports a microwave signal, and a common circuit that supports the direct current and the microwave signal. The method can also comprise operatively coupling a first end of the direct current circuit and a first end of the microwave circuit to a first end of the common circuit. The direct current circuit can comprise a bandstop circuit and the microwave circuit can comprise a capacitor. Alternatively, the direct current circuit can comprise a bandstop circuit and the microwave circuit can comprise a bandpass circuit. Alternatively, the microwave circuit can comprise a capacitor and the direct current circuit can comprise one or more quarter-wavelength transmission lines.