A multi-path voltage-controlled oscillator (VCO) includes a VCO core circuit and a control voltage generator circuit. The VCO core circuit includes a varactor that has a control node for receiving a control voltage. The control voltage generator circuit receives at least one proportional path (P-path) control input and an integral path (I-path) control input, and generates and outputs the control voltage to the control node of the varactor according to the at least one P-path control input and the I-path control input.

A self-operating oscillator which increases an input DC voltage by a coefficient factor of 4 or more is provided. The self-operating oscillator includes a primary LC tank pair, a secondary LC tank pair, and a switch pair. The primary and the secondary LC tank provide a differential sinusoidal output voltage which corresponds to high amplitude, low phase noise and high purity.

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.

According to one or more embodiments, a semiconductor integrated circuit device includes a first inductor portion, a second inductor portion, and a third inductor portion. The first inductor portion is in a first region of a first wiring layer. The second inductor portion is disposed in a second region of the first wiring layer. The third inductor portion is on a second wiring layer spaced from the first wiring layer in a first direction. The third inductor portion includes a first end portion electrically connected to a first end of the first inductor portion, a second end portion electrically connected to a first end of the second inductor portion, and a third end portion between the first and second end portions. The first inductor portion, the second inductor portion, and the third inductor portion constitute an inductor element.

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.

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.

Transformer circuitry comprising: a transformer having a primary coil and a secondary coil, the primary coil having first and second primary terminals and the secondary coil having first and second secondary terminals, and a secondary coil driver configured to drive a secondary voltage signal V2 across the secondary terminals which has a target relationship with a primary voltage signal V1 driven across the primary terminals by a primary coil driver so that an inductance value measured between the primary terminals is governed by the target relationship.

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.

An IQ signal source (100) includes: a Q-VCO (3) having a first VCO (1) and a second VCO (2), the IQ signal source (100) outputting an I signal and a Q signal by electrically coupling the first VCO (1) and the second VCO (2) with each other; a first PLL (10) for comparing a frequency of the I signal or the Q signal with a frequency of a reference signal input from the outside of the IQ signal source (100) and outputting a voltage depending on a result of the comparison; and a second PLL (9) for detecting an IQ phase difference and outputting a voltage depending on the IQ phase difference. The IQ phase difference converges to 90 degrees in dependence on the output voltage of the first PLL (10) and the output voltage of the second PLL (9).

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 comprises includes a plurality of unit variable reactance structures comprising 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 comprising including a first tuning signal and a second tuning signal. An embodiment of a tunable oscillator comprises includes a resonance circuit, a negative impedance structure and a variable reactance apparatus configured for tuning of the oscillator. An embodiment of a method comprises 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.