International Journal of Circuit Theory and Applications

Cover image for Vol. 44 Issue 2

Edited By: Ángel Rodríguez-Vázquez

Impact Factor: 1.254

ISI Journal Citation Reports © Ranking: 2014: 124/249 (Engineering Electrical & Electronic)

Online ISSN: 1097-007X

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Special issue call for papers: Secure lightweight crypto-hardware

Do you want your article to be considered for the special issue "Secure lightweight crypto-hardware"?

The International Journal of Circuit Theory and Applications solicits papers on crypto-hardware at a circuit level to foster this area's active research.

Find out which topics will be included in this special issue and how to submit.

Key Dates

Articles due for review: 31st March 2016

Publication date (tentative): December 2016

Recently Published Articles

  1. Window functions and sigmoidal behaviour of memristive systems

    P. S. Georgiou, S. N. Yaliraki, E. M. Drakakis and M. Barahona

    Article first published online: 3 FEB 2016 | DOI: 10.1002/cta.2186

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    Memristive systems are commonly modelled using empirically defined window functions. We demonstrate that under general conditions, each window can be associated with a sigmoidal. Based on this explicit relation, we derive windows suitable for the mesoscopic modelling of memristive systems from a variety of well-known sigmoidals. Such sigmoidals are defined in terms of measured variables and can thus be extracted from the input/output of a device and then transformed to its corresponding window.

  2. 67 GHz three-spiral transformer CMOS oscillator

    Domenico Pepe, Ilias Chlis and Domenico Zito

    Article first published online: 1 FEB 2016 | DOI: 10.1002/cta.2194

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    This paper presents a 67GHz LC oscillator exploiting a three-spiral transformer and implemented in 65 nm bulk complementary metal–oxide–semiconductor technology by STMicroelectronics. The measured phase noise amounts to −96 dBc/Hz at a 1 MHz frequency offset from the carrier while operating with a 1.2 V supply and −88.7 dBc/Hz at a 1 MHz frequency offset from the carrier while operating with a 0.6 V supply.

  3. Theoretical study and optimisation of a standard deviation estimator circuit for adaptive threshold spike detection

    François Rummens, Stéphane Ygorra, Hol C. Mayiss Boussamba, Sylvie Renaud and Noëlle Lewis

    Article first published online: 26 JAN 2016 | DOI: 10.1002/cta.2192

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    This paper studies a circuit estimating the standard deviation of the noise in electrophysiological recordings, before threshold-based spike detection. Its behaviour is nonlinear and stochastic. This article proposes for the first time a thorough modelling of this circuit. Two models are developed: one, nonlinear, reproduces accurately and quickly the circuit behaviour; the other, linear, provides a transfer function, with analytic expression of circuit performances, based on design parameters, which allows the rational sizing of the loop controller. Thus, an integrated implementation of this circuit is proposed and simulated.

  4. On the existence of chaos in the electronically adjustable structures of the state variable filters

    Jiri Petrzela

    Article first published online: 22 JAN 2016 | DOI: 10.1002/cta.2193

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    This paper shows the existence of chaos in well-known Kerwin–Huelsman–Newcomb filters with piecewise-linear feedback transfer functions; such configurations are typical for electronically adjustable/reconfigurable filters, which became recently quite popular. Strange attractors are observed by using numerical analysis of mathematical model as well as by experimental measurement of voltage-mode circuit structure. Conversion of input harmonic waveform into chaotic output signal is confirmed by the presence of positive largest Lyapunov exponent.

  5. Gain compression improvement on low-power cascaded current reuse LNAs

    Marco Silva Pereira, João Caldinhas Vaz, Carlos Azeredo Leme and João Costa Freire

    Article first published online: 15 JAN 2016 | DOI: 10.1002/cta.2191

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    Current reuse low-noise-amplifiers (CRLNAs) have been the norm to achieve high-gain and low-noise figure under low-power budgets. However, conventional CRLNAs suffer from a severe lack of large-signal linearity, especially in conventional cascaded CRLNAs. This main drawback is related with the typical biasing method imposed in the output stage. To prove our point, a large-signal study is performed for a single stage common-source in two distinct biasing situations: voltage biased and current biased. On the basis of the gathered results, a new CRLNA solution is proposed to relief the large-signal bottleneck. The suggested design is analyzed in a 0.13 µm complementary metal–oxide–semiconductor standard process. Post-layout simulations show 8 dB compression point improvement compared with the conventional CRLNA solution. The CRLNA draws a current of 650 μA from a 1.2 V supply. At 2.45 GHz, a power gain of 25.3 dB and a NF of 2.3 dB are achieved, while the IIP3 is −9 dBm.