A voltage controlled oscillator includes a variable capacitance circuit having a plurality of variable capacitance elements, each having a capacitance that is a function of a tuning voltage, two or more oscillator core circuits, each operable over a specified frequency band, and inductive elements connected between the variable capacitance circuit and the oscillator core circuits.

A low voltage inverter-based amplifier includes a first inverter-based amplification module, a second inverter-based amplification module, an inverter-based feedforward module, and an inverter-based common mode detector. The first inverter-based amplification module receives an input signal. The second inverter-based amplification module receives the input signal through the inverter-based feedforward module, and receives a first output signal from the first inverter-based amplification module. The inverter-based common mode detector receives an amplified signal from the second inverter-based amplification module, and outputs a feedback signal to the second inverter-based amplification module. Since the first and the second inverter-based amplification modules are both inverter-based, the supply voltage of the low voltage inverter-based amplifier is provided to supply one PMOS and one NMOS for normal operation. Therefore, a number of cascade MOSs of the low voltage inverter-based amplifier is two, and the low voltage inverter-based amplifier can be normally operated under the low supply voltage.

A circuit device includes a control voltage input terminal to which a control voltage is inputted, an A/D conversion circuit A/D-converting the control voltage to generate control voltage data and A/D-converting a temperature detection voltage from a temperature sensor to generate temperature detection data, a processing circuit generating temperature compensation data of an oscillation frequency based on the temperature detection data and performing addition processing of the temperature compensation data and the control voltage data to generate frequency control data of the oscillation frequency, and an oscillation signal generation circuit generating an oscillation signal of the oscillation frequency set by the frequency control data, using the frequency control data and a resonator.

A clock oscillator includes with a pullable BAW oscillator to generate an output signal with a target frequency. The BAW oscillator is based on a BAW resonator and voltage-controlled variable load capacitance, responsive to a capacitance control signal to provide a selectable load capacitance. An oscillator driver (such as a differential negative gm transconductance amplifier), is coupled to the BAW oscillator to provide an oscillation drive signal. The BAW oscillator is responsive to the oscillation drive signal to generate the output signal with a frequency based on the selectable load capacitance. The oscillator driver can include a bandpass filter network with a resonance frequency substantially at the target frequency.

Certain aspects relate to a semiconductor die. The semiconductor die includes a voltage-controlled oscillator (VCO), wherein the VCO includes a resonant capacitor, and a resonant inductor coupled in parallel with the resonant capacitor. The resonant inductor includes a first elongated portion and a second elongated portion that are parallel with each other. The semiconductor die also includes a voltage supply line configured to route a supply voltage to the VCO, wherein the voltage supply line includes a first portion that runs parallel with the first and second elongated portions of the resonant inductor and is located between the first and second elongated portions of the resonant inductor.

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.

Described is a high Q-factor inductor. The inductor is formed as a unit cell coil, which is copied twice for a dual-coil inductor and copied four times for a quad-coil inductor. For each copy of the unit cell coil, the coil is rotated a subsequent substantially 90 degrees or substantially 90 degrees. The rotation enables the terminals of the inductor to be routed equal-distant to a circuit that is placed in the line of symmetry between the two coils.

An oscillator operable in Class-C comprises at least one set of cross-coupled transistors. A threshold voltage of the transistors is controllable by having a bias voltage applied at back-gates of the transistors. The bias voltage thereby controls a conduction angle of the transistors to enable operation of the oscillator in Class-C. There is further provided a radio transceiver comprising such an oscillator, a method of operating such an oscillator, and a controller configured to operate such an oscillator.

An LC oscillator architecture in which an LC tank is driven by a negative resistance element (amplifier) including first and second Vbe/Vgs multipliers cross-coupled to the LC tank. Each Vbe/Vgs multiplier circuitry including a transistor with a control terminal as a negative input, a reference terminal as a positive input, and an output terminal, a shunt resistance connected between the control terminal and the reference terminal, a series resistance connected between the control terminal and the output terminal for one of the same transistor or the other transistor, and a shorting capacitance connected between the control terminal of the transistor, and the output terminal of the transistor of the other Vbe/Vgs multiplier. An example application is an LC VCO, such as for a PLL, CDR, or retimer.

A frequency-modulated continuous-wave radar system includes a waveform generator, a delta-sigma modulation circuit, a voltage controlled oscillator, a frequency divider circuit, a control circuit, an injection locked oscillator, a power amplifier circuit, a first power detection circuit, a second power detection circuit, a third power detection circuit, and a calibration engine circuit. The waveform generator, the delta-sigma modulation circuit, the voltage controlled oscillator, the frequency divider circuit, and the control circuit form a phase locked loop. The calibration engine circuit is coupled to the delta-sigma modulation circuit, the voltage controlled oscillator, the injection locked oscillator, the power amplifier circuit, the first power detection circuit, the second power detection circuit, and the third power detection circuit for adjusting frequency gains of the voltage controlled oscillator, the injection locked oscillator, and the power amplifier circuit to approach wideband flatness frequency responses.