This application note tracks the history of voltage-controlled oscillators (VCOs) since approximately 1910 and provides examples of VCO integration in RF ICs. It traces the technology, and discusses evolution of product performance and size. Future trends are projected. A similar version of this article appeared in the July 2002 issue of Microwaves & RF magazine.

Our study of thalamo-cortical systems suggests a new architecture for a neurocomputer that consists of oscillators having different frequencies and that are connected weakly via a common medium forced by an external input. Even though such oscillators are all interconnected homogeneously, the external input imposes a dynamic connectivity. We use Kuramoto’s model to illustrate the idea and to pr...

Pulsed bias is an attempt to improve the performance of oscillators in integrated circuits as a result of architectural innovation. Given the relatively low value of resonator quality factor achievable on-chip, for a specified bias voltage level, pulsed bias may result in a lower power consumption and in an improvement of the spectral purity of the oscillation. The main drawback of this approac...

As clock speeds and communication channels run at ever higher frequencies, accurate jitter and phase noise measurements become more important, even as they become more difficult and expensive to manage. While measuring ultra low-jitter devices and equipment, the engineer is continually required to ask whether the measurement values are the result of the device under test (DUT) or if they are du...

A PLL circuit includes phase detector for detecting phase error between an input and output signal of the PLL circuit and outputting pump up and pump down signal. A charge pump generates a charge pump signal in response to pump up and pump down signals. A loop filter filters charge pump signal to generate a filtered signal. A boost-up device coupled to loop filter output terminal charges a loop...

Voltage-controlled oscillator (VCO) based ADCs have become a topic of great interest due to the unique and attractive signal-processing properties they offer in the design of oversampling converters. Assuming a ring-oscillator structure, the outputs of a VCO toggle between two discrete levels (VDD and GND) like a CMOS digital gate, enabling simple multibit quantization using Dflip-flops. Since ...

The Voltage Controlled Oscillator (VCO) is one of the most important components for highfrequency transceivers. In this work IBM SiGe 0.5μm technology is used to design an on-chip VCO and MCM-D technology is used to design the VCO with off-chip varactors, inductors and capacitors. Theses results are measured at centre frequency of 2.5GHz and with a voltage supply of 3.3volts. The phase noise of...

A new electronically tunable differential integrator (ETDI) and its extension to voltage controlled quadrature oscillator (VCQO) design with linear tuning law are proposed; the active building block is a composite current feedback amplifier with recent multiplication mode current conveyor (MMCC) element. Recently utilization of two different kinds of active devices to form a composite building ...

Semiconductor process variation and reliability aging effect on CMOS VCO performance has been studied. A technique to mitigate the effect of process variations on the performances of nano-scale CMOS LC-VCO is presented. The LC-VCO compensation uses a process invariant current source. VCO parameters such as phase noise and core power before and after compensation over a wide range of variability...

This paper presents the design and analysis of a novel 2.4 GHz Voltage Controlled Oscillator (VCO), with amplitude control and Q enhancement circuit, for wireless communication applications. The variable capacitors and the inductors were designed using ANSYS and imported through DAC components in ADS (Advanced Design software). Accurate simulation of the VCO was performed in the software enviro...