A programmable resistor can provide discrete logarithmic (linear-in-dB) gain control. It can include multiple like programmable resistor subnetworks or cells, such as can be connected in parallel, such as according to a decoding scheme. The subnetworks can be configured to cover a subrange such as [0 dB, 6 dB) relative to the maximum resistance value. Coarse increments of 6 dB can be further added to this range by successively doubling the number of subnetworks that are connected in parallel. An additional decoder help ensure a linear control curve, free of dead zones or other nonlinearities. The programmable resistor can be suitable for use in such circuits as programmable-gain amplifiers, filters, or more complex networks, such as where the resistance can be programmed as a function of a digital code. An example including a tuning circuit for a variable gain active filter is described.

The present disclosure may include, for example, a tunable capacitor having a decoder for generating a plurality of control signals, and an array of tunable switched capacitors comprising a plurality of fixed capacitors coupled to a plurality of switches. The plurality of switches can be controlled by the plurality of control signals to manage a tunable range of reactance of the array of tunable switched capacitors. Additionally, the array of tunable switched capacitors is adapted to have non-uniform quality (Q) factors. Additional embodiments are disclosed.

The present disclosure may include, for example, a tunable capacitor having a decoder for generating a plurality of control signals, and an array of tunable switched capacitors comprising a plurality of fixed capacitors coupled to a plurality of switches. The plurality of switches can be controlled by the plurality of control signals to manage a tunable range of reactance of the array of tunable switched capacitors. Additionally, the array of tunable switched capacitors is adapted to have non-uniform quality (Q) factors. Additional embodiments are disclosed.

Systems and implementations for inductance tuning systems that are configured to operate in a wide range of frequencies are provided herein. The subject matter described herein can in some embodiments include an inductance tuning system including at least one inductor connected to a first terminal, the at least one inductor comprising of a plurality of inductive elements that are substantially magnetically coupled to each other, wherein spacing between the inductive elements are substantially less than diameters of the windings. At least one capacitor can be connected between one or more of the plurality of inductive elements and a second terminal.

Systems and implementations for inductance tuning systems that are configured to operate in a wide range of frequencies are provided herein. The subject matter described herein can in some embodiments include an inductance tuning system including at least one inductor connected to a first terminal, the at least one inductor comprising of a plurality of inductive elements that are substantially magnetically coupled to each other, wherein spacing between the inductive elements are substantially less than diameters of the windings. At least one capacitor can be connected between one or more of the plurality of inductive elements and a second terminal.

A power control circuit comprising a power supply and a load, the load being synthesized from an impedance synthesizer comprising two-terminal impedance elements connected in series and grouped in impedance modules. The impedance elements in each impedance module are of equal value, while those between the modules bear ratios uniquely defined according to the numbers of impedance elements in the impedance modules. A number of switches associated with said impedance elements short out a selected number of the impedance elements under the control of a first analog signal which may be preprocessed by an analytic function. The analog signal is converted to digital signals by an analog-to-digital converter, then level shifted to control the switches associated with the impedance elements, whereby the amount of power delivered to the load is controllable by the first analog signal. Pulse-width-modulation is deployed to further control the power by a second analog signal, with additional benefit of overload protection.

A resonant circuit includes a resonator. An inductor is connected in parallel with the resonator. An inductor is connected in series with the parallel circuit formed of the resonator and the inductor. Further, a variable capacitor is connected in parallel with a series circuit formed of the inductor and the parallel circuit formed of the resonator and the inductor. The variable capacitor is connected in series with these circuits. As a result, a resonant circuit and a high-frequency filter supporting more communication signals are provided.

A resonant circuit includes a resonator. An inductor is connected in parallel with the resonator. An inductor is connected in series with the parallel circuit formed of the resonator and the inductor. Further, a variable capacitor is connected in parallel with a series circuit formed of the inductor and the parallel circuit formed of the resonator and the inductor. The variable capacitor is connected in series with these circuits. As a result, a resonant circuit and a high-frequency filter supporting more communication signals are provided.

Systems and implementations for inductance tuning systems that are configured to operate in a wide range of frequencies are provided herein. The subject matter described herein can in some embodiments include an inductance tuning system including at least one inductor connected to a first terminal, the at least one inductor comprising of a plurality of inductive elements that are substantially magnetically coupled to each other, wherein spacing between the inductive elements are substantially less than diameters of the windings. At least one capacitor can be connected between one or more of the plurality of inductive elements and a second terminal.

Systems and implementations for inductance tuning systems that are configured to operate in a wide range of frequencies are provided herein. The subject matter described herein can in some embodiments include an inductance tuning system including at least one inductor connected to a first terminal, the at least one inductor comprising of a plurality of inductive elements that are substantially magnetically coupled to each other, wherein spacing between the inductive elements are substantially less than diameters of the windings. At least one capacitor can be connected between one or more of the plurality of inductive elements and a second terminal.