Certain aspects provide a circuit for generating an oscillating signal. The circuit generally includes a voltage-controlled oscillator (VCO) having cross-coupled transistors, a first capacitive element and a second capacitive element coupled to the cross-coupled transistors, and a first inductive element and a second inductive element coupled to the cross-coupled transistors. First terminals of the first inductive element and the second inductive element are coupled to first terminals of the first capacitive element and the second capacitive element, respectively. The circuit also includes a control circuit having an output coupled to a supply voltage node at second terminals of the first inductive element and the second inductive element, and a feedback path coupled between the VCO and an input of the control circuit.

A frequency generation solution controls an oscillator amplitude using two feedback paths to generate high frequency signals with lower power consumption and lower noise. A first feedback path provides continuous control of the oscillator amplitude responsive to an amplitude detected at the oscillator output. A second feedback path provides discrete control of the amplitude regulating parameter(s) of the oscillator responsive to the detected oscillator amplitude. Because the second feedback path enables the adjustment of the amplitude regulating parameter(s), the second feedback path enables an amplifier in the first feedback path to operate at a reduced gain, and thus also at a reduced power and a reduced noise, without jeopardizing the performance of the oscillator.

A transconductance controlling circuit is provided. The transconductance controlling circuit includes a resonance circuit, a negative-resistance unit-circuit and a transconductance boosting circuit. The resonance circuit generates an oscillation signal. The negative-resistance unit-circuit is coupled to a resonance circuit and includes a first transistor and a second transistor. The transconductance boosting circuit is coupled to the negative-resistance unit-circuit and includes a third transistor and a fourth transistor. A first drain of the first transistor is coupled to a third drain of the third transistor, a first gate of the first transistor is coupled to a third gate of the third transistor, the first gate of the first transistor is coupled to a second drain of the second transistor, and a first base of the first transistor is coupled to a fourth base of the fourth transistor and to a fourth source of the fourth transistor.

A transconductance controlling circuit is provided. The transconductance controlling circuit includes a resonance circuit, a negative-resistance unit-circuit and a transconductance boosting circuit. The resonance circuit generates an oscillation signal. The negative-resistance unit-circuit is coupled to a resonance circuit and includes a first transistor and a second transistor. The transconductance boosting circuit is coupled to the negative-resistance unit-circuit and includes a third transistor and a fourth transistor. A first drain of the first transistor is coupled to a third drain of the third transistor, a first gate of the first transistor is coupled to a third gate of the third transistor, the first gate of the first transistor is coupled to a second drain of the second transistor, and a first base of the first transistor is coupled to a fourth base of the fourth transistor and to a fourth source of the fourth transistor.

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.

A local oscillator device includes an oscillator module including a first inductive element and a capacitive element coupled in parallel with the inductive element. A frequency divider is coupled to the oscillator module for delivering a local oscillator signal. The local oscillator device includes an autotransformer including the first inductive element and two second inductive elements respectively coupled to the terminals of the first inductive element and to two output terminals of the autotransformer, the output terminals being further coupled to input terminals of the frequency divider.

An electronic device comprises a first feedback circuit operatively connected to an amplitude detector and a first control input of an oscillator. The first feedback circuit is configured to control an amplitude of an output of the oscillator by continuously applying a first control signal to the first control input in response to an amplitude detected by the amplitude detector. The electronic device further comprises a second feedback circuit operatively connected to the amplitude detector and a second control input of the oscillator. The second feedback circuit is configured to modify one or more amplitude regulating parameters of the oscillator by providing a second control signal in response to the amplitude being beyond an upper or lower amplitude threshold, and refrain from modifying the one or more amplitude regulating parameters when the amplitude is within the upper and lower amplitude thresholds.

An LC oscillator powering arrangement comprises an LC oscillator configured to provide an oscillating signal output; a current source configured to supply the LC oscillator with a supply current, the current source during operation being controlled by a control voltage and supplied with a supply voltage subject to supply voltage ripple; and a replication block configured to generate an amplified replica of the supply voltage ripple directly from the supply voltage and to overlay the replica on the control voltage.

A method for tuning a current source of a digitally controlled oscillator having an LC tank having a tunable capacitor bank includes: determining a specific threshold according to a resolution of a bit number of the tunable capacitor bank; configuring a current flowing through the current source at a first current level; tuning the current flowing through the current source from the first current level to a lower current level; comparing a variation of a digital value of the tunable capacitor bank with the specific threshold, the digital value corresponding to the lower current level; and determining that a current level required by the digitally controlled oscillator is decreased down to the lower current level and then configuring the current flowing through the current source at the lower current level if the variation of the digital value is smaller than the specific threshold.

A voltage-controlled oscillator, including a voltage-controlled LC resonator including at least one first output node; an amplifier including at least one first dual-gate MOS transistor including first and second gates, coupling the first output node to a second node of application of a reference potential; and a regulation circuit capable of applying to the second gate of the first transistor a bias voltage variable according to the amplitude of the oscillations of a signal delivered on the first output node of the oscillator.