Technologies for impedance matching networks for qubits are disclosed. In one illustrative embodiment, an impedance matching network matches a 50 Ohm transmission line to a spin qubit with a state-dependent resistance of 100 kiloohms to 105 kiloohms. The illustrative impedance matching network is tunable, allowing the impedance transformation ratio to be changed without significantly changing the matching frequency of the impedance matching network. In some embodiments, the impedance matching network matches a 50 Ohm transmission line to a lower-resistance state of a qubit. In other embodiments, the impedance matching network matches a 50 Ohm transmission line to an impedance value in between a lower-resistance state and a higher-resistance state of a qubit.

Disclosed is a gallium arsenide (GaAs) enabled tunable filter for, e.g., 6 GHz Wi-Fi RF Frontend, with integrated high-performance varactors, metal-insulator-metal (MIM) capacitors, and 3D solenoid inductors. The tunable filter comprises a hyper-abrupt variable capacitor (varactor) high capacitance tuning ratio. The tunable filter also comprises a GaAs substrate in which through-GaAs-vias (TGV) are formed. The varactor along with the MIM capacitors and the 3D inductors is formed in an upper conductive structure on upper surface of the GaAs substrate. Lower conductive structure comprising lower conductors is formed on lower surface of the GaAs substrate. Electrical coupling between the lower and upper conductive structures is provided by the TGVs. The tunable filter can be integrated with radio frequency front end (RFFE) devices.

A filter circuit includes a branch line coupler and a balun circuit having an input terminal connected to the branch line coupler to receive a signal, a first line connected to the input terminal and having a length comparable to a quarter of an electrical length of one wavelength at a frequency of the signal, a second line connected to the input terminal and having a length comparable to the quarter, a third line connected to the second line and having a length comparable to the quarter, and a fourth line connected to the third line and electromagnetically coupled to the first line, the fourth line having a length comparable to the quarter, wherein an end of the first line and an end of the fourth line are both connected to a ground or open-circuited, or are connected to two respective terminating resistors whose resistance values are equal.

RF duplexing and methods of operating the same are described herein. In one embodiment, an RF duplexing system may include a control circuit and a duplexer with a first tunable RF filter and second tunable RF filter. The control circuit is operable in a full duplexing transmission mode and a half duplexing transmission mode. The control circuit tunes the first tunable RF filter in the full duplexing transmission mode so that the first tunable RF filter defines a transmission passband and tune the second tunable RF filter so that the second tunable RF filter defines a receive passband. Also, the control circuit tunes one of the tunable RF filters so that the tunable RF filter defines the passband while the other tunable RF filter enhances the passband. In this manner, the tunable RF filters in the duplexer are both utilized to get better performance during the half duplexing mode.

The embodiments relate to a steering system. A steering system according to an embodiment may include a steering assistance device configured to assist a steering device positioned between a steering wheel and a wheel, and a noise reduction device configured to reduce noise of the steering system with the steering assistance device.

The invention relates to a filter, for example, a switchable harmonic filter for the gigahertz range. A first line segment, which can comprise a radial stub leads away from a main line of the filter. A second line segment can be electrically connected to the first line segment. At least two electronically controllable switching elements are provided, by means of which the first and the second line segment can be connected.

A multi-bit digital signal that is generated by modulating a baseband signal by a modulation circuit and includes components in a radio frequency band is amplified by switch-mode amplifiers (100-1, 100-2) on a bit-by-bit basis, amplified signals are band-limited by frequency-variable variable band limiting units (201-1, 201-2) and thereafter subjected to voltage-to-current conversion by voltage/current source conversion units (202-1, 202-2) provided with variable capacitances, the signals converted to current are synthesized at a synthesis point X, and a resultant signal is impedance-corrected by an impedance correction unit (203) and output as a transmission signal to an antenna of a load (300). Consequently, the present invention provides a transmitter capable of synthesizing output signals from a plurality of switch-mode amplifiers and transmitting a resultant signal while maintaining an impedance characteristic with respect to a plurality of transmit frequencies without increasing a circuit size.

An electromagnetic coupler includes a first transmission line connecting an input port to an output port. A second transmission line adjacent the first transmission line connects a coupled port and an isolation port. The electromagnetic coupler provides a coupled signal at the coupled port, which is representative of an input signal at the input port. The amplitude of the coupled signal is related to the amplitude of the input signal by a coupling factor. A tuning element is provided adjacent to the first or second transmission line and is coupled to an impedance. Varying impedance values cause an adjustment to the coupling factor and reactive impedance values provide frequency filtering effects.

A noise filter includes: a first bus bar that is electrical wiring of a flat plate, the first bus bar including a first extending wiring portion extending in a first direction, a second extending wiring portion extending in a second direction that is a direction opposite to the first direction, and a first coupling wiring portion connecting the first extending wiring portion and the second extending wiring portion; a first lead conductor having a first end connected with the first coupling wiring portion; a first capacitor having a first end connected with a second end of the first lead conductor and a second end connected with a ground; and a magnetic core having an opening in a central portion, the magnetic core disposed in such a manner that the first coupling wiring portion passes through the opening.

A method and apparatus for use in a digitally tuning a capacitor in an integrated circuit device is described. A Digitally Tuned Capacitor DTC is described which facilitates digitally controlling capacitance applied between a first and second terminal. In some embodiments, the first terminal comprises an RF+ terminal and the second terminal comprises an RF− terminal. In accordance with some embodiments, the DTCs comprise a plurality of sub-circuits ordered in significance from least significant bit (LSB) to most significant bit (MSB) sub-circuits, wherein the plurality of significant bit sub-circuits are coupled together in parallel, and wherein each sub-circuit has a first node coupled to the first RF terminal, and a second node coupled to the second RF terminal. The DTCs further include an input means for receiving a digital control word, wherein the digital control word comprises bits that are similarly ordered in significance from an LSB to an MSB.