Abstract: A strain compensated heterostructure comprising a substrate comprising silicon carbide material; a first epitaxial layer comprising single-crystal aluminum nitride material formed on a top surface of the substrate; a second epitaxial layer formed on the first epitaxial layer opposite the top surface of the substrate, the second epitaxial layer comprising single-crystal scandium aluminum nitride material; and a third epitaxial layer formed on the second epitaxial layer opposite the first epitaxial layer, the third layer comprising single-crystal aluminum nitride material.

Abstract: Embodiments of a single-chip ScAIN tunable filter bank include a plurality of switching elements, and a plurality of channel filters integrated on a monolithic platform. The monolithic platform may comprise a single crystal base and each of the switching elements may comprise at least one of a scandium aluminum nitride (ScAIN) or other Group III-Nitride transistor structure fabricated on the single crystal base. In these embodiments, each channel filter comprises a multi-layered ScAIN structure comprising one or more a single-crystal epitaxial ScAIN layers fabricated on the single crystal base. The ScAIN layers for each channel filter may be based on desired frequency characteristics of an associated one of the RF channels.

Abstract: A method includes receiving a radio frequency (RF) input signal using at least one non-reciprocal circulator. The method also includes generating an RF output signal using at least one of one or more reflective circuit elements. Each reflective circuit element is configured to receive an RF signal from the at least one non-reciprocal circulator and to provide a modified RF signal to the at least one non-reciprocal circulator. The RF output signal represents the RF input signal as modified by the at least one of the one or more reflective circuit elements.

Abstract: A method includes receiving a radio frequency (RF) input signal using at least one non-reciprocal circulator. The method also includes generating an RF output signal using at least one of multiple reflective filter elements. Each reflective filter element is configured to receive an RF signal from the at least one non-reciprocal circulator and to provide a filtered RF signal to the at least one non-reciprocal circulator. The reflective filter elements include amplitude change reflectors configured to modify amplitudes of the RF signal at different frequencies. The RF output signal represents the RF input signal as modified by the at least one of the reflective filter elements.

Abstract: A strain compensated heterostructure comprising a substrate comprising silicon carbide material; a first epitaxial layer comprising single-crystal aluminum nitride material formed on a top surface of the substrate; a second epitaxial layer formed on the first epitaxial layer opposite the top surface of the substrate, the second epitaxial layer comprising single-crystal scandium aluminum nitride material; and a third epitaxial layer formed on the second epitaxial layer opposite the first epitaxial layer, the third layer comprising single-crystal aluminum nitride material.

Abstract: Embodiments of a single-chip ScAIN tunable filter bank include a plurality of switching elements, and a plurality of channel filters integrated on a monolithic platform. The monolithic platform may comprise a single crystal base and each of the switching elements may comprise at least one of a scandium aluminum nitride (ScAIN) or other Group III-Nitride transistor structure fabricated on the single crystal base. In these embodiments, each channel filter comprises a multi-layered ScAIN structure comprising one or more a single-crystal epitaxial ScAIN layers fabricated on the single crystal base. The ScAIN layers for each channel filter may be based on desired frequency characteristics of an associated one of the RF channels.

Abstract: A method includes receiving a radio frequency (RF) input signal using at least one non-reciprocal circulator. The method also includes generating an RF output signal using at least one of one or more reflective circuit elements. Each reflective circuit element is configured to receive an RF signal from the at least one non-reciprocal circulator and to provide a modified RF signal to the at least one non-reciprocal circulator. The RF output signal represents the RF input signal as modified by the at least one of the one or more reflective circuit elements.

Abstract: A method includes receiving a radio frequency (RF) input signal using at least one non-reciprocal circulator. The method also includes generating an RF output signal using at least one of multiple reflective filter elements. Each reflective filter element is configured to receive an RF signal from the at least one non-reciprocal circulator and to provide a filtered RF signal to the at least one non-reciprocal circulator. The reflective filter elements include amplitude change reflectors configured to modify amplitudes of the RF signal at different frequencies. The RF output signal represents the RF input signal as modified by the at least one of the reflective filter elements.

Abstract: A frequency selective limiter (FSL) is provided having a transmission line structure with a tapered width. The FSL includes a magnetic material having first and second opposing surfaces. A first conductor is disposed on the first surface of the magnetic material, where a width of the first conductor decreases from a first end of the FSL to a second end of the FSL along a length of the FSL. Two second conductors are disposed on the second surface of the magnetic material, where a width of a gap between the two second conductors decreases from the first end of the FSL to the second end of the FSL along a length of the FSL. The first conductor and two second conductors form a biplanar waveguide transmission line.

Abstract: A frequency selective limiter (FSL) having an input port and an output port can comprise a plurality of vertically stacked transmission line structures. Each of the transmission line structures can be electrically coupled to a transmission line structure disposed directly above it and with a first one of the plurality of vertically stacked transmission line structures having one end corresponding to the FSL input port and a second one of the plurality of vertically stacked transmission line structures having one end corresponding to the FSL output port. Each of the plurality of vertically stacked transmission line structures can comprise a magnetic material having first and second opposing surfaces and one or more conductors disposed on at least one of the surfaces of the magnetic material.

Abstract: A frequency selective limiter (FSL) is provided having a transmission line structure with a tapered width. The FSL includes a magnetic material having first and second opposing surfaces. A first conductor is disposed on the first surface of the magnetic material, where a width of the first conductor decreases from a first end of the FSL to a second end of the FSL along a length of the FSL. Two second conductors are disposed on the second surface of the magnetic material, where a width of a gap between the two second conductors decreases from the first end of the FSL to the second end of the FSL along a length of the FSL. The first conductor and two second conductors form a biplanar waveguide transmission line.

Abstract: A transmission line transformer having a time delay network having a signal terminal and a pair of output terminals connected to the signal terminal through a corresponding one of a pair of time delay elements, the delay line elements having different time delays. A pair of transmission lines, each one having a pair of electrically coupled elements. A first one of the elements in one of the transmission lines has a first end connected to one of the pair of output terminals. A second one of the elements in such one of the transmission lines has a second end connected to a second end of one of the pair of elements in the other one of the transmission lines. The first one of the pair of elements in the other one of the pair of transmission lines is coupled to a second one of the pair of output terminals.

Abstract: A transmission line transformer having a time delay network having a signal terminal and a pair of output terminals connected to the signal terminal through a corresponding one of a pair of time delay elements, the delay line elements having different time delays. A pair of transmission lines, each one having a pair of electrically coupled elements. A first one of the elements in one of the transmission lines has a first end connected to one of the pair of output terminals. A second one of the elements in such one of the transmission lines has a second end connected to a second end of one of the pair of elements in the other one of the transmission lines. The first one of the pair of elements in the other one of the pair of transmission lines is coupled to a second one of the pair of output terminals.