Apparatus and methods of automatically trimming a PCB-based LC circuit. The apparatus may comprise an interface to a printed circuit board (PCB). The PCB may include a PCB inductor and a PCB capacitor to form an LC circuit. The LC circuit may have an LC circuit frequency. The apparatus may comprise a variable capacitor communicatively coupled to the interface and configured to adjust an effective capacitance of the LC circuit.

Rotary traveling wave oscillators (RTWOs) with distributed stubs are provided. In certain embodiments, an RTWO includes segments that are implemented using distributed stubs to mitigate flicker noise upconversion arising from transmission line dispersion. For example, a distance between the distributed stubs can be selected to intentionally generate a phase difference between transmission line modes, thereby cancelling out phase shifts due to transmission line dispersion. In particular, each segment is subdivided into multiple transmission line sections with a maintaining amplifier electrically connected to one of the sections and a tuning capacitor array connected to adjacent transmission line sections.

An active feedback RF resonator has a signal loop having a signal input and a signal output. The signal loop has a variable gain stage and at least one variable resonator, each variable resonator comprising an inductance element and a variable capacitance element comprising a number of switched fixed value capacitors and a variable capacitor. A phase noise of the active feedback RF signal has a maximum value for an operating frequency of the variable resonator that is based on an operating range of the variable capacitor.

Apparatus and methods of automatically trimming a PCB-based LC circuit. The apparatus may comprise an interface to a printed circuit board (PCB). The PCB may include a PCB inductor and a PCB capacitor to form an LC circuit. The LC circuit may have an LC circuit frequency. The apparatus may comprise a variable capacitor communicatively coupled to the interface and configured to adjust an effective capacitance of the LC circuit.

Described is a high Q-factor inductor. The inductor is formed as a unit cell coil, which is copied twice for a dual-coil inductor and copied four times for a quad-coil inductor. For each copy of the unit cell coil, the coil is rotated a subsequent substantially 90 degrees or substantially −90 degrees. The rotation enables the terminals of the inductor to be routed equal-distant to a circuit that is placed in the line of symmetry between the two coils.

A low-temperature radio-frequency tuning circuit has a capacitor and an inductor. The capacitor has a capacitance between two electrodes associated with a dielectric medium, and the capacitance is tunable. The medium is a quantum paraelectric material. The capacitance is tunable by application of a voltage to apply an electric field to the medium. The capacitance is tunable at a temperature of less than 4 K by use of the quantum paraelectric material as the dielectric medium.

The application discloses a method, for building an oscillator frequency adjustment lookup table in a transceiver, wherein the transceiver generates a clock according to a crystal oscillator external to the transceiver for transceiving data. The transceiver includes adjustable capacitor arrays assembly connected to the crystal oscillator, wherein when an equivalent capacitance of the adjustable capacitor assembly is a reference value, the crystal oscillator has a reference frequency, and when the equivalent capacitance changes relative to the reference value, the crystal oscillator correspondingly has a frequency offset relative to the reference frequency. The method includes: performing an interpolation operation according to a first value, a second value, and a third value of the equivalent capacitance, and the corresponding frequency variations, so as to obtain the frequency variations corresponding to a first sub-value between the first value and the second values.

The multi-modal imaging system, in particular for brain imaging, comprising a pump signal generator which emits at least one pump signal in the radio frequency (RF)-range with a first power P1 and a second power P2, a wireless detection unit, which comprises at least one parametric resonator circuit with multiple resonance modes, wherein the at least one parametric resonator circuit comprises at least two varactors, at least one capacitor and at least one inductance, wherein, in a first detection mode, the pump signal, having a first power P1, induces a first pump current in the at least one parametric resonator circuit, wherein the at least one parametric resonator circuit is operated below its oscillation threshold and generates a first output signal by amplifying a first input signal, which is provided due to a magnetic-resonance (MR) measurement, wherein an external receiving device receives the first output signal, wherein, in a second detection mode, the pump signal, having a second power P2, induces a second pump current in the at least one parametric resonator circuit, wherein the at least one parametric resonator circuit is operated above its oscillation threshold and generates a second output signal, wherein the second output signal is modulated with a second input signal, wherein the second input signal is provided by at least one neuronal probe device, connected to the at least one parametric resonator circuit, wherein the external receiving device receives the second output signal.

A circuit device includes an oscillation circuit and a processing circuit that generates capacitance control data. The oscillation circuit includes a variable capacitance circuit whose capacitance value is variably controlled based on the capacitance control data, and an oscillation frequency thereof is controlled based on the capacitance value of the variable capacitance circuit. The variable capacitance circuit includes a capacitor array. The capacitor array includes a plurality of capacitors each having a binary-weighted capacitance value, and a plurality of switches that are on-off controlled based on the capacitance control data. The processing circuit outputs the capacitance control data, which is subjected to dithering, so as to switch the capacitance value of the variable capacitance circuit between a first capacitance value and a second capacitance value in a time division manner.

A high-frequency circuit device includes: a chip which includes a high-frequency element, a high-frequency circuit, a signal conductor, and a chip ground; a package substrate on which the chip is disposed, a shunt path which is constituted by a package signal conductor which is disposed on an upper surface of the package substrate and is electrically connected to the signal conductor, a package first ground which is electrically connected to the chip ground, and a shunt element which is electrically connected to the package signal conductor and the package first ground; and a package second ground which is disposed at least inside the base of the package substrate or on a back surface of the package substrate, wherein a part of the base, a part of the shunt path, and the package second ground constitute a capacitive structure.