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 30-MHz low-jitter high-linearity CMOS voltage-controlled oscillator

Abstract: A fully monolithic voltage-controlled oscillator (VCO) with an on-chip timing capacitor and a maximum oscillation frequency of 30 MHz is reported. Using a novel on-chip servo loop, the VCO displays less than 0.17% nonlinearity in its voltage-frequency transfer function from 1 to 15 MHz without trimming. An improved circuit topology that provides a large swing on the timing capacitor allows the VCO to obtain a cycle-to-cycle jitter of less than 100 p.p.m. The circuit operates on a 5-V supply with a die size of 104 mil/spl times/154 mil.

A BiCMOS Dual-Band Millimeter-Wave Frequency Synthesizer for Automotive Radars

Abstract: Design and implementation of a millimeter-wave dual-band frequency synthesizer, operating in the 24 GHz and 77 GHz bands, are presented. All circuits except the voltage controlled oscillators are shared between the two bands. A multi-functional injection-locked circuit is used after the oscillators to simplify the reconfiguration of the division ratio inside the phase-locked loop. The 1 mm times 0.8 mm synthesizer chip is fabricated in a 0.18 mum silicon-germanium BiCMOS technology, featuring 0.15 mum emitter-width heterojunction bipolar transistors. Measurements of the prototype demonstrate a locking range of 23.8-26.95 GHz/75.67-78.5 GHz in the 24/77 GHz modes, with a low power consumption of 50/75 mW from a 2.5 V supply. The closed-loop phase noise at 1 MHz offset from the carrier is less than -100 dBc/Hz in both bands. The frequency synthesizer is suitable for integration in direct-conversion transceivers for K/W-band automotive radars and heterodyne receivers for 94 GHz imaging applications.

A method and arrangement for frequency synthesis

Abstract: The present invention relates to frequency synthesis with a controlled oscillator (20) included in a phase locked loop, where the frequency of the oscillator output signal is divided (22) periodically by different integers, such that the frequency is, on average, divided by a value which is equal to an integer N plus or minus a numeric fraction whose absolute value is smaller than one. The phase position of pulses formed in this way is compared with the phase position of pulses which derive from a reference signal (10, 12), therewith forming a phase error signal. For the purpose of suppressing periodic variations of an oscillator control signal as a result of phase jitter, there is added or subtracted to the phase error signal, in a known manner, a correction value (24, 26) which is dependent on the aforementioned numeric fraction. In order to eliminate the need to multiply the correction value by a factor which is proportional to the inverted value of the integer N, the phase error signal is instead amplified with a factor N (28) prior to adding or subtracting the correction value. The loop bandwidth is also held constant in this way.

Voltage controlled ring oscillator with wide tuning range and fast voltage swing

Abstract: A new design of a voltage controlled ring oscillator is proposed. The proposed design allows an implementation of a low frequency ring oscillator using relatively small devices and less stages. A voltage controlled ring oscillator with tuning range from 40 Hz to 380 MHz is achieved using the proposed method. In addition, the proposed circuit enables the output voltage to swing faster than the conventional one.

Ideal phase-locked-loop (PLL) operation of a 10 GHz erbium-doped fibre laser using regenerative modelocking as an optical voltage controlled oscillator

Abstract: Ideal phase-locked-loop (PLL) operation of a 10 GHz erbium doped fibre laser has been achieved for the first time by using a voltage controlled regenerative modelocking technique. The repetition rate of the regeneratively modelocked fibre laser in a free running condition can be continuously varied by changing the voltage supplied to the PZT to change the fibre cavity length. PLL operation is achieved by feeding back a phase sensitive error signal to the PZT. This signal is obtained by mixing a laser clock signal with a synthesizer signal. The external signal tracking range is 40 kHz.