A voltage-controlled oscillator (VCO) having an operating frequency dependent on a total capacitance of selectable tuning capacitors can be fabricated within an integrated circuit (IC). The VCO can include active electronic devices fabricated within a set of lower layers of the IC and selectable tuning capacitors having electrically conductive structures separated by dielectric material fabricated within a set of upper layers of the IC. The upper layers of the IC are located above the set of lower layers of the IC. The VCO can also include a set of interconnect structures configurable to select a total capacitance of the selectable tuning capacitors by electrically interconnecting the first portion of the VCO to capacitors of the at least one selectable tuning capacitor.

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.

An oscillator includes: an external terminal, a resonator, and an oscillation circuit that oscillates the resonator, in which the oscillation circuit includes an amplification circuit and a current source which supplies a current to the amplification circuit, in which the current is set according to a first control signal which is input from the external terminal and a drive level of the resonator is changed according to the setting of the current.

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 multimode, multicore inductor-capacitor (LC) oscillator having an increased oscillation frequency tuning range, and related method, are provided. The oscillation frequency tuning range of existing oscillators is limited. LC oscillators are known to have very low phase noise but a narrow frequency tuning range. The present oscillator has at least two LC oscillator cores and is capable of operating in multiple different modes of oscillation thereby increasing its overall oscillation frequency tuning range. A set of programmable amplifier pairs is used to force particular relative oscillation phases at the nodes of the multiple cores of the oscillator to realize one or more additional modes of oscillation for the oscillator. The additional oscillation mode increases the frequency tuning range of the oscillator.

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.

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.

Disclosed are a metal-semiconductor-metal two-dimensional electron gas varactor (MSM-2DEG) and a method of manufacturing the same. There is provided an MSM-2DEG varactor having an asymmetric structure, which includes a first gate formed on a semiconductor layer, and a second gate spaced apart at a predetermined distance from the first gate and formed on the semiconductor layer, wherein the first gate and the second gate are different in shape and gate length.

A circuit device includes a drive circuit driving a resonator, an oscillation circuit having the resonator and a variable capacitance circuit coupled to an oscillation loop including the drive circuit, and a D/A converter circuit that performs D/A conversion on frequency control data and outputs a first voltage signal and a second voltage signal which are differential signals. The variable capacitance circuit includes a first variable capacitance capacitor, to one end of which the first voltage signal is input and, to the other end of which a first bias voltage is input and a second variable capacitance capacitor, to one end of which the second voltage signal is input and, to the other end of which a second bias voltage is input.

A multimode, multicore inductor-capacitor (LC) oscillator having an increased oscillation frequency tuning range, and related method, are provided. The oscillation frequency tuning range of existing oscillators is limited. LC oscillators are known to have very low phase noise but a narrow frequency tuning range. The present oscillator has at least two LC oscillator cores and is capable of operating in multiple different modes of oscillation thereby increasing its overall oscillation frequency tuning range. A set of programmable amplifier pairs is used to force particular relative oscillation phases at the nodes of the multiple cores of the oscillator to realize one or more additional modes of oscillation for the oscillator. The additional oscillation mode increases the frequency tuning range of the oscillator.