Inductor-capacitor oscillators and common mode resonators are provided. The inductor-capacitor oscillator includes a first transistor, a second transistor, an inductor, a first capacitor, a second capacitor, a first winding, and a second winding. The first transistor has a first terminal, a second terminal, and a third terminal. The second transistor has a fourth terminal, a fifth terminal and a sixth terminal. The first, second and third terminals are electrically connected to the fifth, fourth and sixth terminals, respectively. The first capacitor and the inductor are coupled between the first terminal and the fourth terminal. The second capacitor is coupled between the third terminal and a reference voltage. The first winding is coupled between the third terminal and the reference voltage. The second winding is coupled between the third terminal and the reference voltage. The first winding and the second winding are symmetric to each other.

A frequency doubler (tripler, or quadrupler) employs current re-use coupled oscillator technique to enhance phase noise without increasing current consumption. Frequency doubler uses coupling between two oscillators running at different frequencies; a first oscillator is running at the target frequency and a second oscillator is running at half the frequency. The coupling between the two oscillators is via a transformer having a primary transformer coil and a secondary transformer coil. The first oscillator comprises a differential inductor, coarse/fine tuning capacitor arrays, and an n-type trans-conductor (GM). A virtual ground node of the n-type GM is coupled to one side of the primary transformer coil and the other side of the primary coil is coupled to the center tap of the secondary coil. The second oscillator comprises the secondary coil, coarse/fine tuning capacitor arrays, n-type GM, frequency tracking loop (FTL) and 2.sup.nd-harmonic LC filter network.

There are provided an oscillator circuit and a radio receiver capable of reducing a frequency fluctuation of an oscillation frequency to a small extent. There is provided an oscillator circuit including an LC oscillator circuit, an amplitude detection circuit, and a bias generation circuit, in which the LC oscillator circuit includes an inductor and at least one variable capacitance element, the amplitude detection circuit detects an oscillation amplitude of the LC oscillator circuit and converts the oscillation amplitude into a DC voltage, and the bias generation circuit compares the DC voltage with a voltage for generating a bias signal, the voltage changing on the basis of a temperature fluctuation of the bias generation circuit, calculates a difference between the DC voltage and a voltage after the change, and generates, on the basis of the difference, a bias signal that reduces a fluctuation in the oscillation amplitude, to control the oscillation amplitude.

A DC-DC converter includes a transformer having primary and secondary windings, a power oscillator applying an oscillating signal to the primary winding to transmit a power signal to the secondary winding, a rectifier obtaining an output DC voltage by rectifying the power signal at the secondary winding, and comparison circuitry generating an error signal representing a difference between the output DC voltage and a reference voltage value. A transmitter connected to the secondary winding performs an amplitude modulation of the power signal at the secondary winding to transmit an amplitude modulated power signal to the primary winding, the amplitude modulation based upon the error signal and modulating a stream of data to the primary winding. A receiver coupled to the primary winding demodulates the amplitude modulated power signal to recover the error signal and the stream of data. An amplitude of the oscillating signal is controlled by the error signal.

The smart window for the smart home and smart grid can harvest energy and supply power to the home, grid and window itself. The smart window for the smart home and smart grid has all the Electrochromic panel, Solar panel and Multimedia panel been the same full window wide view and aligned with each other in IGU. To be a home automation system, the smart window has local/remote access/control capabilities. There are several types of smart windows working as master device or slave device. The operation of smart window automation system has three modes, normal/open mode, shut/tint mode and smart phone mode. The tube of air circulation system is hidden inside the frame surrounding IGU. Most of the electronic components are integrated to be FPSOC Field Programmable System On Chip that all the electronic component is hidden in the frame surrounding IGU, too. Therefore, the smart window doesn't have any blockage of window view with the Solar panel, Electrochromic panel, Multimedia panel and air circulation system. The smart window has the clean outlook as the conventional dual panel IGU does. The master device of the smart window system is similar to the huge screen working as a smart phone. In normal/open mode, the smart window is similar to the conventional dual panel window having the full-panel clean and clear view. For the different architectures of the smart homes, the smart window must have versatile alignments and system control that the smart window has to be implemented with the Field Programmable System On Chips of Anlinx, Milinx and Zilinx made of the W5RS advanced FPSOC chip technologies.

A semiconductor device according to the present embodiment includes a plurality of switching elements and a plurality of variable capacitance elements. The switching elements are switching elements connected in series between a first control terminal and a second control terminal and plural types of capacitance control signals can be supplied to the first control terminal and the second control terminal. The variable capacitance elements have capacitance control terminals connected to corresponding one ends of the switching elements, respectively.

A frequency synthesizer (230) is described that includes: a voltage controlled oscillator, VCO (330); a VCO bias circuit (370), operably coupled to the VCO (330) and configured to provide a controllable bias current (384) of the VCO (330); a temperature sensor (372) located in the frequency synthesizer (230) and configured to determine an operating temperature of the frequency synthesizer (230); an analog-to-digital converter, ADC (376), operably coupled to the temperature sensor (372) and configured to provide a digital representation (378) of the determined operating temperature; and a bias control circuit (380) operably coupled to the ADC (376) and the VCO bias circuit (370) and configured to provide a bias control signal (382) to the VCO bias circuit (370) based on the determined operating temperature of the frequency synthesizer (230). The VCO bias circuit (370) is configured to adjust the controllable bias current (384) applied to the VCO based on the bias control signal (382). The frequency synthesizer (230) includes a digitally-controlled bias current adjustment method for a wideband low noise VCO, for example using idle time intervals of signal transitions.

An oscillator operable in Class-C comprises at least one set of cross-coupled transistors. A threshold voltage of the transistors is controllable by having a bias voltage applied at back-gates of the transistors. The bias voltage thereby controls a conduction angle of the transistors to enable operation of the oscillator in Class-C. There is further provided a radio transceiver comprising such an oscillator, a method of operating such an oscillator, and a controller configured to operate such an oscillator.

There is provided a semiconductor device including an oscillation circuit that includes a plurality of capacitors provided on a semiconductor substrate, a conversion circuit that converts an analog signal into a digital signal, and a switch circuit that switches the capacitors on the basis of the digital signal. Further, an oscillation frequency linearly varies with respect to a variation in the analog signal.

A variable reactance apparatus, tunable oscillator and method for changing a gain associated with an input signal of a tunable oscillator are disclosed. An embodiment of the variable reactance apparatus includes a plurality of unit variable reactance structures including respective control input nodes, and a control circuit configured to connect each of the control input nodes to a respective signal from among a plurality of signals including a first tuning signal and a second tuning signal. An embodiment of a tunable oscillator includes a resonance circuit, a negative impedance structure and a variable reactance apparatus configured for tuning of the oscillator. An embodiment of a method includes altering connections of first and second tuning signals to control input nodes of respective first and second sets of unit variable reactance structures while holding constant a sum of the number of unit variable reactance structures in the first and second sets.