Voltage-controlled oscillator

About: Voltage-controlled oscillator is a research topic. Over the lifetime, 23896 publications have been published within this topic receiving 231875 citations. The topic is also known as: VCO.

A low-noise, low-power VCO with automatic amplitude control for wireless applications

Abstract: Voltage controlled oscillators (VCOs) used in portable wireless communications applications, such as cellular telephony, are required to achieve low phase-noise levels while consuming minimal power. This paper presents the design challenges of a VCO with automatic amplitude control, which operates in the 300 MHz to 1.2 GHz frequency range using different external resonators. The VCO phase noise level is -106 dBc/Hz at 100-KHz offset from an 800-MHz carrier, and it consumes 1.6 mA from a 2.7-V power supply. An extensive phase-noise analysis is employed for this VCO design in order to identify the most important noise sources in the circuit and to find the optimum tradeoff between noise performance and power consumption.

Capacitive responsive electronic switching circuit

Abstract: A capacitive responsive electronic switching circuit comprises an oscillator providing a periodic output signal having a frequency of 50 kHz or greater, an input touch terminal defining an area for an operator provide an input by proximity and touch, and a detector circuit coupled to the oscillator for receiving the periodic output signal from the oscillator, and coupled to the input touch terminal. The detector circuit being responsive to signals from the oscillator and the presence of an operator's body capacitance to ground coupled to the touch terminal when in proximity or touched by an operator to provide a control output signal. Preferably, the oscillator provides a periodic output signal having a frequency of 800 kHz or greater. An array of touch terminals may be provided in close proximity due to the reduction in crosstalk that may result from contaminants by utilizing an oscillator outputting a signal having a frequency of 50 kHz or greater.

Monolithic microwave integrated circuit (MMIC) waveguide resonators having a tunable ferroelectric layer

Abstract: A ferroelectric loaded waveguide resonator capable of operation at microwave, millimeter-wave and higher frequencies and suitable for integration into a three-dimensional monolithic microwave integrated circuit (3D MMIC) is disclosed. The resonator includes a resonator cavity, which, in one form of the invention, is formed by two parallel metal layers and a metallized wall structure extending between the metal layers. The cavity is filled with dielectric material and includes a layer of ferroelectric material, which is used to control the resonant frequency by varying a voltage bias applied to the ferroelectric layer. The cavity includes a slot in one of the metal layers and a coupling strip formed adjacent to the slot to provide electromagnetic coupling to other components, such as a voltage controlled oscillator (VCO). The invention can also be applied to other multi-metal semiconductor or wafer level packaging technologies.

Voltage controlled oscillator, mmic, and high frequency wireless device

Abstract: A voltage controlled oscillator having low phase noise and including: a variable resonator including a varactor and a control voltage terminal; and an open-end stub connected in parallel to the variable resonator, the open-end stub having a length shorter than or equal to an odd multiple of one quarter of a wavelength of a harmonic signal plus one sixteenth of the wavelength of the harmonic signal, and longer than or equal to an odd multiple of one quarter of the wavelength of the harmonic signal minus one sixteenth of the wavelength of the harmonic signal. In this structure, a high Q value is realized for a fundamental wave frequency. Fluctuation in a control voltage due to a harmonic signal is controlled.

A 1.8-GHz monolithic LC voltage-controlled oscillator

Abstract: The authors describe a monolithic LC VCO (voltage-controlled oscillator) for use in the microwave frequency range. The circuit does not require any external components, but instead relies on characteristics inherent in the circuit configuration for frequency tuning. A simplified circuit schematic of the LC VCO is shown. A monolithic LC VCO achieves a measured tuning range of 200 MHz, extending from 1.68 GHz to 1.86 GHz. >