This paper discusses the ability to obtain periodic steady-state solutions for fractional nonlinear circuit problems. For a class of nonlinear problems with fractional derivatives (based on the Caputo or Riemann–Liouville definitions), a methodology is proposed to derive equations representing the dependencies between the harmonics of the sought variables. Two approaches are...

The concept of frequency interleaving (FI) for digital-to-analog converters (DACs) has recently experienced renewed interest, in order to overcome the DACs’ bandwidth limitations. In this concept, the output signals of multiple DACs are interleaved in the frequency domain in order to generate a combined output signal that exceeds both the sampling rate and the bandwidth of a...

The original version of the article unfortunately contained an error in figure. The presentation of Fig. 2 is incorrect. Figure 1 was erroneously duplicated and published as Fig. 2 in the article.

This paper describes an approach for an analog electronic circuit specification quick verification that is based on a simple mathematical model determined during the before-test stage statistical analysis. Generally, the observed performance parameters (e.g., cutoff frequency, phase shift at the assumed frequency point) are calculated from the Walsh–Hadamard transform components...

This paper presents a novel approach to design orthogonal wavelets matched to a signal with compact support and vanishing moments. It provides a systematic and versatile framework for matching an orthogonal wavelet to a specific signal or application. The central idea is to select a wavelet by optimizing a criterion which promotes sparsity of the wavelet representation of a...

The authors of this paper study the synthesis of new models and methods for signal detection in additive correlated non-Gaussian noise. A new moment quality criterion decision making is proposed based on a random process description using moments and a formation of polynomial decision rules. Taking into account parameters of non-Gaussian distribution of random variables (such as...

This paper proposes a new solution of an ultra-low-energy analog comparator, dedicated to slope analog-to-digital converters (ADC), particularly suited for CMOS image sensors (CISs) featuring a large number of ADCs. For massively parallel imaging arrays, this number may be as high as tens-hundreds of thousands ADCs. As each ADC includes an analog comparator, the number of these...

The authors present a novel design algorithm for 3-D orthogonal filters. Both separable and non-separable cases are discussed. In the separable case, the synthesis leads to a cascade connection of 1-D systems. In the latter case, one obtains 2-D systems followed by a 1-D one. Realization techniques for these systems are presented which utilize Givens rotations and delay elements...

The classical principles of Wiener filter design consider only the causality constraint. However, additional constraints are often involved in practice. This paper provides a comprehensive theoretical approach for designing Wiener filters with constraint conditions beyond causality. Using integration, we first derive an extension of the Wiener–Hopf equation with an additional...

This work presents the integrated, multichannel readout circuit dedicated to FET-based THz detectors. Described solution provides an unique approach to FET detectors readout, able to replace the measurement equipment deploying the lock-in technique and to eliminate the necessity of modulating the THz wave. The IC proposed by the authors is based on the chopper amplifier...

This paper presents the design methods of residue-to-binary (reverse) converters for the new flexible balanced five-moduli set \(\{ 2^k, 2^n-1, 2^n+1,\) \(2^{n+1}-1, 2^{n-1}-1 \}\) for the pairs of positive integers \({n \ge 4}\) (even) and any \({k>0}\), which can provide the exact required dynamic range of the residue number system. This modulus set is the generalisation of the...

The invariant zeros, input-decoupling and output-decoupling zeros and blocking zeros of positive electrical circuits with zero transfer matrices are addressed. It is shown that the positive electrical circuits have no invariant zeros, input–output-decoupling zeros and blocking zeros and also the list of eigenvalues of the system matrix is the sum of the list of input-decoupling...

This paper proposes an effective approach to the computation of the discrete fractional Fourier transform for an input vector of any length N. This approach uses specific structural properties of the discrete fractional Fourier transformation matrix. Thanks to these properties, the fractional Fourier transformation matrix can be decomposed into a sum of three or two matrices, one...

This article introduces a current-mode field-programmable analog array (FPAA) architecture with its programming methods. The biggest benefit of the proposed approach is solving the problem of implementing reconfigurable analog circuits in modern nanometre technologies. It is achieved thanks to adopting a switched-current (SI) technique which allows to implement the array using...

Typical approach to non-integer order filtering consists of analogue design and implementation. Digital realization of non-integer order systems is susceptible to problems such as infinite memory requirement and sensitivity to numerical errors. The aim of this paper is to present two efficient methods for digital realization of non-integer order filters: discrete time-domain...

Results of analysis of transient states in a series circuit of the class \({RL}_{\beta }{C}_{\alpha }\), supplied by an ideal voltage source, have been described in the paper. This circuit consists of a coil \({L}_{\beta }\) and a supercapacitor \({C}_{\alpha }\) described by fractional-order differential equations. A method for determining the current and voltage waveforms in...

The paper is devoted to variable order estimation process when measurements are obtained in two different ways: directly and by lossy network. Since the problem of fractional order estimation is highly nonlinear, dual estimation algorithm based on Unscented Fractional Order Kalman filter has been used. In dual estimation process, state variable and order estimation have been...

Multiple-input multiple-output (MIMO) detection algorithms have received considerable research interest in recent years, as a result of the increasing need for high data-rate communications. Detection techniques range from the low-complexity linear detectors to the maximum likelihood detector, which scales exponentially with the number of transmit antennas. In between these two...