Apparatus and methods for tunable filtering are provided. In certain embodiments, a tunable filter is implemented using one or more controllable capacitors formed on a semiconductor die and using one or more shielded integrated inductors formed on a secondary circuit board that attaches to a carrier circuit board. Additionally, the shielded integrated inductors are formed from patterned metallization layers of the secondary circuit board, and shielding is provided on the secondary circuit board and/or the carrier circuit board to shield the inductors from the semiconductor die and/or other components.

Apparatus and methods for control and calibration of tunable filters are provided. In certain embodiments, a tunable filter includes at least one controllable component (for instance, a controllable inductor or a controllable capacitor) having a value that changes or adjusts a center frequency of the tunable filter. For example, the controllable component can correspond to a controllable inductor or a controllable capacitor of an inductor-capacitor (LC) resonator of the tunable filter. The tunable filter further includes a control circuit implemented with an approximation function for estimating a value of the controllable component for achieving a desired center frequency indicated by a frequency control signal.

A dual mode notch filter for use in a multi-band millimeter wave (mmW) transmitter includes a transmit filter circuit disposed between two amplifiers in a mmW transmit signal path, the transmit filter circuit formed by at least one switch, at least one capacitor, and a double-tuned transformer, the transmit filter circuit having at least two modes configured to selectively filter a spurious signal in at least a first communication band.

Techniques for creating a low pass filter associated with a flux line are presented. A qubit device can comprise a first substrate and second substrate. A low pass filter, comprising at least one inductor and at least one capacitor can be formed, wherein respective components of or associated with the low pass filter can be formed on the first or second substrates, and wherein one or more bump bonds can extend between the substrates to connect respective components that are on respective substrates. The filter can receive an input signal via an input line and filter the signal to produce a filtered signal as output to a flux line that is in proximity to a coupler with SQUID loop and one or more flux-tunable qubits that are formed on one of the substrates. The filter can reduce electrical noise and Purcell decay associated with the flux line.

Customizable tunable filters are provided herein. In certain implementations, a tunable filter including: a first filter bank including a plurality of high-pass filters each having a different cutoff frequency, and a second filter bank including a plurality of low-pass filters each having a different cutoff frequency. The tunable filter further includes a first pair of switches configured to select a first filter chosen from the first filter bank, and a second pair of switches configured to select a second filter chosen from the second filter bank. The tunable filter operates with a first cutoff frequency of the first filter and with a second cutoff frequency of the second filter.

An apparatus and method for a frequency based integrated circuit that selectively filters out unwanted bands or regions of interfering frequencies utilizing one or more tunable notch or bandpass filters or tunable low or high pass filters capable of operating across multiple frequencies and multiple bands in noisy RF environments. The tunable filters are fabricated within the same integrated circuit package as the associated frequency based circuitry, thus minimizing R, L, and C parasitic values, and also allowing residual and other parasitic impedance in the associated circuitry and IC package to be absorbed and compensated.

A wide-bandwidth resonant circuit is provided. In an embodiment disclosed herein, the wide-bandwidth resonant circuit includes a positive resonant circuit coupled in parallel to a negative resonant circuit. The positive resonant circuit and the negative resonant circuit can be configured to collectively exhibit certain impedance characteristics across a wide bandwidth. As a result, it is possible to utilize the wide-bandwidth resonant circuit to support a variety of wide-bandwidth applications, such as in a wide-bandwidth signal filter circuit.

The disclosure relates to an electrical component, for example, a surface-mount resonator, including a distributed-element circuit disposed on a dielectric base and separated from an electromagnetic field modification member by a gaseous gap, wherein a frequency characteristic of the electrical component can be tuned by positioning the electromagnetic field modification member relative to the distributed-element circuit using an actuator.

Systems and methods herein provide for a tunable resonator. In one embodiment, a tunable resonator includes a transmission line comprising at least two inductor segments and a tap between each of the at least two inductor segments. The resonator also includes one less switch than a number of the at least two inductor segments on the transmission line. Each switch is coupled to one of the taps. And, each switch is operable to decouple at least one of the at least two inductor segments in the transmission line by shunting at least a portion of the transmission line to ground to change a resonant frequency of the transmission line.

An adjustment method for filter units in a plasma processing apparatus includes a first measurement process of measuring a frequency characteristic of a reference filter unit selected among the filter units, and an adjustment process of adjusting a frequency characteristic of each of remaining filter units selected among the filter units excluding the reference filter unit. Further, the adjustment process includes an attachment process of attaching a capacitive member for adjusting a capacitance between wirings in each of the remaining filter units, a second measurement process of measuring a frequency characteristic of each of the remaining filter units to which the capacitive member is attached, and an individual adjustment process of adjusting a capacitance of the capacitive member such that the frequency characteristic of each of the remaining filter unit to which the capacitive member is attached becomes close to the frequency characteristic of the reference filter unit.