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 local oscillator of the present invention includes: a frequency generator for outputting first and second sinusoidal signals having the same frequency but mutually different phases; a phase detector for outputting either a positive or a negative voltage depending on whether a phase difference between the first and second sinusoidal signals output from the frequency generator is greater than a reference phase difference; and a comparator for outputting a comparison result between a voltage output from the phase detector and a reference voltage, or a comparison result between the voltage output from the phase detector and a voltage obtained by inverting the polarity of the voltage, in which the frequency generator controls the phase of the first sinusoidal signal so that the phase difference approaches the reference phase difference by using the comparison result output from the comparator, enabling generating IQ signals having higher phase accuracy than conventional local oscillators.

The present application relates to a differential Colpitts voltage-controlled oscillator (VCO) circuit, which comprises a pair of transistors with control terminals biased by a common biasing voltage and a pair of couplers arranged to cross-couple corrector/drain of the transistors and the base/gate of the differential transistors. The pair of couplers have a coupling factor k.sub.c, which used to enhance the transconductance of the transistor pair, therefore can be used for power consumption reduction and phase noise minimalization.

Provided is an electronic circuit including a resonant circuit configured to output a resonance voltage having a resonance frequency to a first node, and an oscillation circuit configured to output an oscillation voltage having a level changed according to a first current and a second current based on the resonance voltage received from the first node, wherein the first current is delivered between a first voltage supply terminal and a second node in a first time period, the second current is delivered between the second node and a second voltage supply terminal in a second time period, and a sum of a length of the first time period and a length of the second time period corresponds to the resonance frequency.

An integrated circuit comprising: a substrate; a configurable tank circuit on the substrate, the configurable tank circuit including: a first pair of inductive loops driven in parallel in each of a first configuration and a second configuration, each of the inductive loops in the first pair enclosing a corresponding capacitive element connected in parallel with that inductive loop; a second pair of inductive loops driven in parallel with the first pair of loops in the second configuration, the second pair of inductive loops undriven in the first configuration; and a switch arrangement that alternately places the configurable tank circuit into either of the first and second configurations; and an oscillation driver that drives the configurable tank circuit at a tunable resonance frequency.

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 voltage controlled oscillator (VCO) circuit is disclosed. The VCO circuit comprises a VCO tuning circuit comprising a primary inductive coil. In some embodiments, the VCO tuning circuit is configured to generate a VCO output signal at a first resonance frequency. The VCO circuit further comprises a filter circuit comprising a secondary inductive coil. In some embodiments, the filter circuit is configured to resonate at a second, different, resonance frequency, in order to filter a noise associated with the VCO tuning circuit. In some embodiments, the primary inductive coil associated with the VCO tuning circuit and the secondary inductive coil associated with the filter circuit are concentrically arranged with respect to one another. Further, in some embodiments, the primary inductive coil associated with the VCO tuning circuit and the secondary inductive coil associated with the filter circuit are magnetically decoupled with respect to one another.

An example oscillator device comprises (i) an oscillation circuit arranged for generating and outputting an oscillation signal and comprising an active circuit to ensure oscillation is maintained, (ii) a voltage-to-current conversion replica circuit of the active circuit arranged for receiving the oscillation signal and for outputting a current proportional to the oscillation signal, (iii) biasing means arranged to generate a constant bias current to activate the oscillation circuit, and (iv) subtraction means for subtracting the current proportional to the oscillation signal from the bias current, thereby obtaining a resulting current which can be used for adapting the oscillation signal's amplitude.

The present invention provides a continuous time circuit including an amplifier and a RC calibration circuit. In the operations of the continuous time circuit, the amplifier is configured to amplify an input signal to generate an output signal, and the RC calibration circuit is configured to adjust a capacitance of a compensation capacitor of the amplifier according to a RC product measurement result.

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.