Analysis and Design of Quadrature Oscillators

Oliveira, Luís B.; Fernandes, Jorge; Filanovsky, I.M.; Verhoeven, C.J.M.; Silva, Manuel M.

doi:10.1007/978-1-4020-8516-1

Cited by 59 publications

(47 citation statements)

References 7 publications

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“…In recent years, significant research efforts have been invested in the study of oscillators with accurate quadrature outputs, with particular emphasis on cross-coupled RC and LC oscillators [1], [2], [3]. Typically, coupled oscillators require two extra gain blocks with current sources.…”

Section: Introductionmentioning

confidence: 99%

“…Typically, coupled oscillators require two extra gain blocks with current sources. This increases the power dissipation, reduces the oscillation frequency [1], and prevents use of low supply voltages. Recently, capacitive coupling has been proposed for LC oscillators [4], [5] to obtain in-phase and quadrature outputs.…”

Section: Introductionmentioning

confidence: 99%

“…It is known that inductorless (RC) oscillators [1], [2] occupy less area than LC oscillators. Since they do not require technologies with many metal layers and a thick top layer for the design of high Q inductors, their fabrication cost is much lower.…”

Section: Introductionmentioning

confidence: 99%

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A High-Level Model for Capacitive Coupled RC Oscillators

Casaleiro

Oliveira

2012

Technological Innovation for Value Creation

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Abstract. In this paper a high-level model is proposed for quadrature oscillators that are based on two RC oscillators with capacitive coupling. The capacitive coupling technique has the advantages of being noiseless and not increasing the power requirements, which are important features for low power receivers. This coupling technique was already study for LC oscillators but not for RC oscillators. Simulations showed that the behavior of capacitive coupling in RC oscillators is different than for LC. In opposition to what was expected, in RC oscillators, the oscillation frequency increases almost linearly and proportional to the coupling capacitances. This behavior can be explained by the presented model. Simulations are presented to validate the model in respect to the oscillation frequency and to the output phases of the oscillator.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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A High-Level Model for Capacitive Coupled RC Oscillators

Casaleiro

Oliveira

2012

Technological Innovation for Value Creation

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“…The need for a high tuning range favors the use of a two-integrator quadrature oscillator [2]. This well-known oscillator type is shown in fig.…”

mentioning

confidence: 99%

“…Obviously, the need for such an automatic gain control loop adds significantly to the complexity of the oscillator. Another approach for stabilizing the amplitude uses integrators with soft-limiting non-linearity [2]. While the complexity of this approach is low, the amount of non-linearity is very critical: over-compensation of damping results in severe distortion, while with under-compensation the circuit fails to oscillate.…”

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confidence: 99%

Simple quadrature oscillator for BIST

2010

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In this letter, a simple quadrature oscillator for built-in self-test (BIST) of integrated analog filters is proposed. A new hardware-efficient approach for amplitude control is described, with as main assets: (i) the technique requires little hardware which makes it very useful for BIST, (ii) the oscillation amplitude is well defined, and (iii) the distortion-level introduced by the amplitude control loop is under control of the designer.Introduction Quadrature oscillators are used in a number of diverse applications. In telecommunication systems they are key building blocks in many (de)modulation schemes. However, quadrature oscillators are also useful in instrumentation and measurement systems, e.g., measuring an unknown impedance as a function of frequency [1]. The focus of this letter is on another instrumentation-related application: built-in self-test (BIST) of integrated analog filters. Here, the in-fase signal v I of the quadrature oscillator is applied to the analog filter to be tested ( fig. 1). The output voltage of the filter is then demodulated by means of the quadrature signals for extracting amplitude and fase information of the analog filter transfer. In general, it is expected that the importance of such built-in self-test feature will steadily grow to guarantee proper operation of performance-critical analog blocks.

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An inductorless CMOS quadrature oscillator continuously tuneable from 3.1 to 10.6 GHz

Oliveira

Snelling²,

Fernandes

et al. 2012

Circuit Theory & Apps

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SUMMARYModern RF front-ends require wide tuning-range oscillators with quadrature outputs. In this paper we present a two-integrator quadrature oscillator, which covers the whole bandwidth of UWB applications. A circuit prototype in a 130 nm CMOS technology is continuously tuneable from 3.1 to 10.6 GHz. The circuit die area is less than 0.013 mm 2 , leading to a figure-of-merit FOMA of −176.7dBc/Hz at the upper frequency. The supply voltage is 1.2 V, and the power consumption is 7 mW at the lower frequency and 13 mW at the upper frequency.

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Analysis and Design of Quadrature Oscillators

Cited by 59 publications

References 7 publications

A High-Level Model for Capacitive Coupled RC Oscillators

A High-Level Model for Capacitive Coupled RC Oscillators

Simple quadrature oscillator for BIST

An inductorless CMOS quadrature oscillator continuously tuneable from 3.1 to 10.6 GHz

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