A quantum computing transducer having a dense, tunable superconducting metamaterial transmission line (SMTL) spectrum that can resonantly enhance sideband scattering. The resonant enhancement of scattering boosts the scattering rate, and hence also the microwave-to-optical-interface (MOQI) transduction efficiency. Moreover, the integration of mechanical elements with the SMTL to realize the MOQI yields a platform that can be readily interfaced on chip, such as in an integrated circuit, with superconducting-qubit architectures to facilitate the local implementation of two of the essential functionalities required for a quantum repeater, i.e., data egress/ingress and a quantum processing module.

An embodiment package comprises an integrated circuit die encapsulated in an encapsulant, a patch antenna over the integrated circuit die, and a dielectric feature disposed between the integrated circuit die and the patch antenna. The patch antenna overlaps the integrated circuit die in a top-down view. The thickness of the dielectric feature is in accordance with an operating bandwidth of the patch antenna.

An architecture for, and techniques for fabricating, a thermal decoupling device are provided. In some embodiments, thermal decoupling device can be included in a thermally decoupled cryogenic microwave filter. In some embodiments, the thermal decoupling device can comprise a dielectric material and a conductive line. The dielectric material can comprise a first channel that is separated from a second channel by a wall of the dielectric material. The conductive line can comprise a first segment and a second segment that are separated by the wall. The wall can facilitate propagation of a microwave signal between the first segment and the second segment and can reduce heat flow between the first segment and the second segment of the conductive line.

A slot antenna includes a substrate having a first side and a second side, a first conductive layer on the first side of the substrate, and a second conductive layer on the second side of the substrate. A first aperture is in the first conductive layer, a second aperture is in the first conductive layer, a first slotline is in the first conductive layer and in communication with the first aperture, and a second slotline is in the first conductive layer and in communication with the second aperture. A third aperture can be in the second conductive layer. A plurality of vias can be in the substrate and surrounding at least a portion of a region including the first aperture, the second aperture, the first slotline, and the second slotline, each of the vias extending through the substrate from the first conductive layer to the second conductive layer.

Optical modulators are described having a Mach-Zehnder interferometer and a pair of RF electrodes interfaced with the Mach-Zehnder interferometer in which the Mach-Zehnder interferometer comprises optical waveguides formed from semiconductor material. The optical modulator also comprises a ground plane spaced away in a distinct plane from transmission line electrodes formed from the association of the pair of RF electrodes interfaced with the Mach-Zehnder interferometer. The ground plane can be associated with a submount in which an optical chip comprising the Mach-Zehnder interferometer and the pair of RF electrodes is mounted on the submount with the two semiconductor optical waveguides are oriented toward the submount. Methods for forming the modulators are described.

A node of a radio frequency waveguide system can include a waveguide interface, a signal splitter, a power rectifier and conditioner, a communication filter, and a network processor. The waveguide interface is configured to communicate through a waveguide in the radio frequency waveguide system. The signal splitter is configured to split a radio frequency transmission received at the waveguide interface between a power path and a communications path within the node. The power rectifier and conditioner are configured to produce a conditioned power signal based on power received through the power path. The communication filter of the communications path is configured to produce a filtered communication signal. The network processor is powered by the conditioned power signal and configured to extract encoded information from the filtered communication signal.

An embodiment package comprises an integrated circuit die encapsulated in an encapsulant, a patch antenna over the integrated circuit die, and a dielectric feature disposed between the integrated circuit die and the patch antenna. The patch antenna overlaps the integrated circuit die in a top-down view. The thickness of the dielectric feature is in accordance with an operating bandwidth of the patch antenna.

A coplanar waveguide transmission line and a design method thereof are provided. The coplanar waveguide transmission line includes a first dielectric substrate, a center conductor strip, and two ground conductor strips. The first dielectric substrate has a first surface and a second surface opposite to each other. The center conductor strip and the ground conductor strips are stacked and fixed to the first surface. The center conductor strip includes a first segment and a second segment. A width of the first segment is greater than a width of the second segment, so that the first segment and the second segment form a step structure. A rectangular groove recessed toward the second surface is defined in the first surface, and a part of the center conductor strip is stacked and fixed to a side, distal from the second surface, of the rectangular groove to form a defected ground structure.

A multilayer substrate includes an insulator that includes a first region and a second region that is thinner than the first region, and a first signal line and a second signal line that are structured to extend across the first region and the second region. In a region in which the first signal line and the second signal line face each other, a line width of the first signal line and a line width of the second signal line are smaller in the second region than in the first region, and a distance between the first signal line and the second signal line is smaller in the second region than in the first region.

A shielded bridge for a coplanar waveguide (CPW) includes a signal bridge extending from a first terminal of the CPW to a second terminal of the CPW. The signal bridge has a raised central portion that extends over a separate signal conductor. The shielded bridge for the CPW also includes a ground bridge extending from a first ground plane on a first side of the separate signal conductor to a second ground plane on a second side of the separate signal conductor. The ground bridge is positioned between the signal bridge and the separate signal conductor.