A programmable variable capacitor includes a fixed varactor controlled by a control voltage connected in a first polarity and a plurality of contingent varactors conditionally controlled by the control voltage in accordance with a plurality of logical signals, respectively, each of said plurality of contingent varactors having: a first varactor controlled by a first voltage connected in the first polarity, a second varactor controlled by a second voltage connected in a second polarity, a first multiplexer configured to output the first voltage by selecting between a first DC (direct-current) voltage and the control voltage in accordance with a respective logical signal among said plurality of logical signals, and a second multiplexer configured to output the second voltage by selecting between a second DC voltage and a medium DC voltage in accordance with the respective logical signal.

A high frequency push-push oscillator is disclosed. The high frequency push-push oscillator includes a resonant circuit, including tank transmission lines or an inductor capacitor (LC) tank circuit, for generating a differential signal having a resonant frequency, and a Gm-core circuit for converting the differential signal to an output signal having an output frequency that is higher than the resonant frequency. The Gm-core circuit includes cross-coupled first and second transistors having first and second gates, drains, and sources, respectively, and first and second gate transmission lines. The first and second drains are in electrical communication with the resonant circuit. The first gate transmission line is joined with the first gate and the resonant circuit and the second gate transmission line is joined with the second gate and the resonant circuit. The Gm-core circuit includes a differential transmission line positioned between the first and second gates of the first and second transistors.

A resonator circuit includes a transformer comprising a primary winding and a secondary winding. The primary winding is inductively coupled with the secondary winding. A primary capacitor is connected to the primary winding. The primary capacitor and the primary winding form a primary circuit. A secondary capacitor is connected to the secondary winding. The secondary capacitor and the secondary winding form a secondary circuit. The resonator circuit has a common mode resonance frequency at an excitation of the primary circuit in a common mode. The resonator circuit has a differential mode resonance frequency at an excitation of the primary circuit in a differential mode. The common mode resonance frequency is different from the differential mode resonance frequency.

Techniques are described for using valley detection for supply voltage modulation in power amplifier circuits. Embodiments operate in context of a power amplifier circuit configured to be driven by a supply voltage generated by a supply modulator and to receive an amplitude-modulated (AM) signal at its input. The output of the power amplifier circuit can be fed to a valley detector that can detect a valley level corresponding to the bottom of the envelope of the AM signal. The detected valley level can be fed back to the supply modulator and compared to a constant reference. In response to the comparison, the supply modulator can vary the supply voltage to the power amplifier circuit in a manner that effectively tracking the envelope of the power amplifier circuit's output signal, thereby effectively seeking a flat valley for the output signal's envelope.

A phased-locked loop (PLL) circuit with an injection locked digital digitally controlled oscillator (ILD) that has an ILD control input element, an ILD injection input element and an ILD output element. The PLL circuit also includes an adaptive control unit (ACU), wherein the ACU is configured to receive an error signal and is configured to output an ILD control word. The ILD control input element is configured to receive the ILD control word, and the ILD control word may set a natural oscillation frequency of the ILD. The ILD is further configured to output a first output signal from the ILD output element, where the natural oscillation frequency may set a frequency of the first output signal.

A device includes a MEMS resonator and oscillator circuit coupled to the MEMS resonator. The circuit includes a first transistor having a first control terminal and first and second current terminals, and a second transistor having a second control terminal and third and fourth current terminals. The circuit includes a resonator coupling network configured to inductively couple MEMS resonator terminals to the first and third current terminals, and to couple the first and third current terminals. The circuit includes a control terminal coupling network configured to couple the first and second control terminals, and to reduce a voltage swing at the first and second control terminals relative to a voltage swing at the first and third current terminals. The circuit includes a second terminal coupling network configured to couple the second and fourth current terminals. A second terminal coupling network resonant frequency is approximately that of MEMS resonator.

A voltage controlled oscillator (VCO) is described. The VCO includes a plurality of nodes coupled with a plurality of transistors, and a first inductor-capacitor (LC) tank coupled with a second LC tank. The first LC tank and the second LC tank include a shared inductor structure coupled to the plurality of nodes. The first LC tank and the second LC tank each include a capacitor. The capacitors are each coupled on a first side to a node of the plurality of nodes and on a second side to a respective capacitor in the other LC tank. The first LC tank and the second LC tank are configured to resonate at a fundamental frequency for differential-mode signals, and the first LC tank and the second LC tank are configured to resonate at twice the fundamental frequency for common-mode signals.

According to some embodiments, an integrated circuit device is disclosed. The integrated circuit device include at least one inductor having at least one turn, a magnetic coupling ring positioned adjacent to the at least one inductor, the magnetic coupling ring comprising at least two magnetic coupling turns, the at least two magnetic coupling turns are disposed adjacent to the at least one turn to enable magnetic coupling between the at least two magnetic coupling turns and the at least one turn The integrated circuit device also includes a power electrode and a ground electrode, wherein the power electrode and the ground electrode are coupled to the at least one inductor and the magnetic coupling ring to provide a first current in the at least one inductor having a direction opposite to a second current in the magnetic coupling ring to cancel at least a portion of a magnetic field generated by the at least one inductor.

The invention relates to a resonator circuit, the resonator circuit comprising a transformer comprising a primary winding and a secondary winding, wherein the primary winding is inductively coupled with the secondary winding, a primary capacitor being connected to the primary winding, the primary capacitor and the primary winding forming a primary circuit, and a secondary capacitor being connected to the secondary winding, the secondary capacitor and the secondary winding forming a secondary circuit, wherein the resonator circuit has a common mode resonance frequency at an excitation of the primary circuit in a common mode, wherein the resonator circuit has a differential mode resonance frequency at an excitation of the primary circuit in a differential mode, and wherein the common mode resonance frequency is different from the differential mode resonance frequency.

A voltage controlled oscillator (VCO) includes: a pair of inductors coupled in series; a first pair of varactors coupled in series, and a second pair of varactors coupled in series. A first common mode node is between the respective varactors of the first pair of varactors and a second common mode node is between the respective varactors of the second pair of varactors. A supply voltage node is switchably coupled to the first common mode node through a first switch, the supply voltage node being a node located between the pair of inductors. A control voltage node (V.sub.C) is switchably coupled to the second common mode node through a second switch.