An on-chip microwave filter circuit includes a substrate formed of a first material that exhibits at least a threshold level of thermal conductivity, wherein the threshold level of thermal conductivity is achieved at a cryogenic temperature range in which a quantum computing circuit operates. The filter circuit further includes a dispersive component configured to filter a plurality of frequencies in an input signal, the dispersive component including a first transmission line disposed on the substrate, the first transmission line being formed of a second material that exhibits at least a second threshold level of thermal conductivity, wherein the second threshold level of thermal conductivity is achieved at a cryogenic temperature range in which a quantum computing circuit operates. The dispersive component further includes a second transmission line disposed on the substrate, the second transmission line being formed of the second material.

A galvanic isolator includes a multi-layer printed circuit board (PCB) including a dielectric material having a top side and a bottom side. An RF transmission line is embedded within the PCB including a plurality of conductor traces spaced apart from one another to include a plurality of gaps (G1 and G2) in a path of the RF transmission line to provide an inline distributed capacitor that together with an impedance of the RF transmission line forms a bandpass (BP) filter. A top metal layer is on the top side and a bottom metal layer on the bottom side connected to one another by a plurality of metal filled vias on respective sides of the RF transmission line. The top metal layer and bottom metal layer each also include at least one gap.

A wide bandpass filtering power amplifier using discriminating coupling is disclosed, which comprises a DC bias circuit, an input impedance matching circuit, a transistor and an output impedance matching circuit. The DC bias circuit is connected to the input impedance matching circuit which is further connected to the transistor, and the transistor is further connected to the output impedance matching circuit which comprises a tuning microstrip line and a bandpass filter. The complexity and the area of the impedance matching circuit in the power amplifier are effectively reduced. At the same time, the filtering PA has good frequency selectivity by using the discriminating coupling BPF. Meanwhile the work efficiency and bandwidth of the filtering power amplifier are effectively improved by taking both of the extended continuous mode theory and filter synthesis theory into account.

Methods of forming flipped radio frequency (RF) filter components are provided. An example method for miniaturizing conventional planar RF filters comprises: determining radio frequency (RF) filtering characteristics of a conventional planar microstrip RF filter or a conventional stripline RF filter, determining distributed RF filter elements for emulating the RF filtering characteristics of the conventional planar microstrip RF filter or the conventional stripline RF filter, creating each distributed RF filter element on a substrate, laminating a stack of the distributed RF filter elements into a single solid RF filter module; and mounting the single solid RF filter module on a horizontal substrate to vertically dispose the distributed RF filter elements of the stack. The methods create laminated stacks of distributed RF filter elements that provide a dramatic reduction in size over the horizontal planar RF filters that they replace. Deposited conductive traces of an example flipped RF filter stack provide various stub configurations of an RF filter and emulate various distributed filter elements and their configuration geometries.

A transmission-line-based impedance transformer including first and second couplers, with each coupler including respective pairs of coupled signal conductors. The signal conductors are connected sequentially in series between an input port and an output port and may form a single spiral configuration. A signal conductor of one coupler may be connected in series between the two signal conductors of another coupler. The couplers have characteristic impedances between an input impedance and an output impedance. A signal conductor of a coupler may include first and second conductor portions disposed in respective spaced-apart parallel planes, with the other signal conductor of the coupler disposed physically directly between the first and second conductor portions. A transmission-line signal conductor in the spiral may be shielded from coupled signal conductors by ground conductors disposed in respective spaced-apart parallel planes on opposite sides of the shielded signal conductor.

A transmission line for transmitting radiofrequency range current between a first conductive element and a second conductive element, the transmission line comprising a signal current line and at least one return current line, the signal current line and the return current line(s) extending in parallel. Each current line comprises at least one first segment and at least one second segment. Each first segment is partially aligned with at least one adjacent second segment, aligned segments being separated by a first dielectric gap, and each aligned first segment and second segment forming a capacitive coupling across the first dielectric gap. This solution enables a transmission line which provides only small capacitive loading onto its surroundings, and which therefore can extend, e.g., through an antenna element without significantly affecting the performance of the antenna element.

An integrated passive device transmission-line resonator is disclosed herein. An example structure of the transmission-line resonator includes a glass substrate having first and second sides, a ground plane, a dielectric layer, and features fabricated from two metal layers. A first metal layer, which is formed on the second side of the glass substrate, includes a first capacitor plate and a conductor that, in conjunction with a portion of the ground plane, realizes a transmission line. A portion of the dielectric layer is disposed between the first capacitor plate and a second capacitor plate, which is formed from a second metal layer and positioned axially above the first capacitor plate, to form a capacitor. A smooth interface between a surface of the second side of the glass substrate and the conductor reduces transmission losses of signals propagating across the transmission line and increases performance of the transmission-line resonator.

Systems, methods, and computer-readable media are disclosed for common mode filters with inverted inductive ground structures. In one embodiment, an example printed circuit board may have a first layer with a pair of differential transmission lines, and a common mode filter embedded in the printed circuit board. The common mode filter may include a signal reference structure and an inductive ground structure. The signal reference structure may include a first rectangular portion, and a second rectangular portion having the same dimensions. The second rectangular portion may be separated from the first rectangular portion by a distance. The inductive ground structure may include a first cell having a first conductive line coupled to a first side of the first rectangular portion and a first edge of the common mode filter, and a second cell having a second conductive line coupled to a first side of the second rectangular portion and the first edge.

An example system includes a communication channel and at least one tuning structure coupled to the communication channel. The tuning structure includes a branch of the communication channel. The tuning structure is to dissipate energy from the communication channel at least at one selected wavelength. The branch of the communication channel is a terminated portion.

The filter unit has a center frequency and comprises a first dielectric substrate, a first conducting plane, and at least one transmission arrangement. The at least one transmission arrangement comprises a shunt node which has a shunt connection to the conducting plane. The electrical length of the shunt connection defines the center frequency of the filter unit. The transmission arrangement further comprises a plurality of transmission lines connected in series between an input port and an output port, wherein each port is connectable to auxiliary systems with a system impedance. Moreover, each transmission line has a characteristic impedance and wherein the characteristic impedance of each transmission line is less than the system impedance.