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.

An isolated power transfer device includes a transformer formed in a multi-layer substrate of an integrated circuit package. A primary winding of the transformer is coupled to a first integrated circuit to form a DC/AC power converter and a secondary winding of the transformer is coupled to a second integrated circuit to form an AC/DC power converter. The first and second integrated circuits are electrically isolated from each other. The first integrated circuit includes a lightly doped drain MOSFET integrated with conventional CMOS devices and the second integrated circuit includes a Schottky diode integrated with conventional CMOS devices. The isolated power transfer device includes a capacitive channel for communication of information across an isolation barrier from the second integrated circuit to the first integrated circuit. Capacitors of the capacitive channel may be formed in the multi-layer substrate of the integrated circuit package.

An ultra-wideband radio frequency transmission system capable of receiving a first signal with discrete levels, and including: a voltage-controlled oscillator capable of supplying a first oscillating signal including an oscillating circuit powered by a power supply circuit comprising at least one first current source controlled by the first signal with discrete levels or a second signal with discrete levels obtained from the first signal with discrete levels; a mixer capable of receiving the first oscillating signal and of supplying a second oscillating signal equal to the first oscillating signal multiplied by a gain which depends on the first signal with discrete levels or on a third signal with discrete levels obtained from the first signal with discrete levels; and an antenna or an electromagnetic coupling device capable of transmitting a radio frequency signal based on the second oscillating signal.

An accurate replica oscillator-based frequency tracking loop (FTL) is provided. The replica oscillator used in the FTL can be at a lower frequency and therefore can consume much lower power compared to a main oscillator, such as an injection locked oscillator (ILO). The proposed FTL accurately sets the free running frequency of an ILO across process, voltage and temperature (PVT). Techniques are also provided to compensate the gain and offset error between the replica oscillator and the ILO.

A voltage-controlled oscillator (VCO), includes a resonator circuit connected to receive an input voltage and having a first output node and a second output node; and at least one cross-coupled switching circuit portion, each cross-coupled switching circuit portion comprising a first transistor having a drain connected to the first output node and a second transistor having a drain connected to the second output node, the first transistor having a gate connected between the drain of the second transistor and the second output node and the second transistor having a gate connected between the drain of the first transistor and the first output node, each of the first and second transistors having a threshold voltage that is determined to be the highest threshold voltage available for the process used to create the VCO.

A first capacitor has a capacitance adjustable to a set point value by application of a bias voltage. A second capacitor also has a capacitance adjustable to a set point value by application of a bias voltage. The first and second capacitors are arranged to receive the same bias voltage generated by a control circuit. The control circuit receiving the set point value as an input and generates that bias voltage in response to a quantity representative of a capacitance of the second capacitor.

A method and system are provided for reducing mismatch between oscillators in an LC VCO array. In an implementation, a method comprises measuring the mismatch between the driver strengths, by measuring the corresponding oscillation amplitudes, and a mismatch between the resonance frequency of each LC VCO in the array of VCOs, and adjusting each LC VCO to reduce the measured amplitude and frequency mismatches. In an implementation, the measuring and adjusting is performed once to calibrate the array of VCOs. In another implementation, the system measures and adjusts the array of VCOs repeatedly. In another implementation, the LC VCO array has a master VCO and a plurality of slave VCOs connected to the master VCO by slave PLLs to reduce phase noise caused by mismatches.

A dual-band voltage controlled oscillator (VCO) includes: a first oscillator circuit including a first inductor; a second oscillator circuit including a second inductor; a first mode switch configured to electrically connect or disconnect a first output terminal of the first oscillator circuit and a first output terminal of the second oscillator circuit; a second mode switch configured to electrically connect or disconnect a second output terminal of the first oscillator circuit and a second output terminal of the second oscillator circuit; a third mode switch configured to electrically connect or disconnect a first terminal of the first inductor and a first terminal of the second inductor; and a fourth mode switch configured to electrically connect or disconnect a second terminal of the first inductor and a second terminal of the second inductor.

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.

An accurate replica oscillator-based frequency tracking loop (FTL) is provided. The replica oscillator used in the FTL can be at a lower frequency and therefore can consume much lower power compared to a main oscillator, such as an injection locked oscillator (ILO). The proposed FTL accurately sets the free running frequency of an ILO across process, voltage and temperature (PVT). Techniques are also provided to compensate the gain and offset error between the replica oscillator and the ILO.