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The work is devoted to the theoretical investigation of the quasi-static magnetoelectric interaction in three-layer structures consisting of a piezoelectric and two magnetic layers with positive and negative magnetostriction. Using the system of elasto- and electrostatics equations for the piezoelectric and magnetostrictive phases, expressions for the electrical response of the structure in a magnetic field are obtained. The contributions from longitudinal and bending deformations are taken into account in value of ME interactions. It is shown that the use of an asymmetric three-layer asymmetric structure leads to an increase in the magnitude of the ME interaction by almost an order of magnitude compared to a two-layer structure. The dependences of the effect magnitude on the thickness of the third layer for the nickel/lead zirconate titanate/metglas structure are presented. [ABSTRACT FROM AUTHOR]

We present the analysis of diabolic points in Hermitian and non-Hermitian electronic dimers. The condition of unbreakable Parity-time symmetry is established for both PT-symmetric ZRC and RLC dimers. We show how appears non-Hermitian degeneracy points in the spectrum and how they are protected against a Hermitian perturbation. When a non- Hermitian perturbation is added in the setup, the non-Hermitian diabolic point (NHDP) turns into a ring of exceptional points as in some Dirac and Weyl semimetals. Some simulations of oscillations around these particular points in LTspice are in perfect accordance with the one predicted analytically and numerically. This work opens a gold road for investigations on topological electrical circuits for robust transport of information at room temperature. [ABSTRACT FROM AUTHOR]

The decomplexification procedure allows one to show mathematically (stricto sensu) the equivalence (isomorphism) between the quantum dynamics of a system with a finite number of basis states and a classical dynamics system. This unique way of connecting different dynamics was used in the past to analyze the relationship between the well-known geometric phase present in the quantum evolution discovered by Berry and its generalizations, with their analogs, the Hannay phases, in the classical domain. In here, this analysis is carried out for several quantum hermitian and non-hermitian PT-symmetric Hamiltonians and compared with the Hannay phase analysis in their classical isomorphic equivalent systems. As the equivalence ends in the classical domain with oscillator dynamics, we exploit the analogy to propose resonant electric circuits coupled with a gyrator, to reproduce the geometric phase coming from the theoretical solutions, in simulated laboratory experiments. [ABSTRACT FROM AUTHOR]

This paper deals with the design of a current-reuse active inductor. Current-reuse active inductor-based voltage-controlled oscillator (CRAI-VCO) with a wide tuning range is designed based on the proposed active inductor. The tuning range of VCO is from 1.25 to 2.5 GHz giving a tuning percentage of 68% at a power consumption of 5 mW. The phase noise obtained is −100 dBc/Hz. The post-layout simulations are carried out in Cadence Virtuoso using UMC 180 nm RFCMOS technology. The circuit occupies an active area of 143 µm × 148 µm. The figure of merit of VCO considering the frequency tuning range is −177.3 dBc/Hz comparable to other state-of-the-art VCO designs. [ABSTRACT FROM AUTHOR]

Color images can be encrypted using a hyperchaotic system in the Discrete Cosine Transform (DCT) and gyrator transform domains. These encryption techniques provide an added layer of security to protect sensitive image data from unauthorized access or tampering. The Red, Green, And Blue (RGB) components of the original color image are encoded into two-dimensional streams, respectively. These two-dimensional streams, representing the RGB components, are then processed by the display or printing device to recreate the full-color image. This paper proposes a new image encryption scheme that integrates DCT and the gyrator transform simultaneously. This innovative approach enhances the security and robustness of image encryption, making it suitable for a wide range of applications in data protection and transmission. Specifically, four chaotic sequences generated by a hyperchaotic system are blended into streams to synthesize complex sequences. Subsequently, the two-dimensional complex streams are scrambled using the discrete cosine transform and encoded back into an image format. Finally, the parameters in the hyperchaotic system using DCT and the gyrator transform improve the security of the proposed scheme. Theoretical and experimental analyses both confirm the security and validity of the proposed work. [ABSTRACT FROM AUTHOR]

A circulator, which is a non-reciprocal device, is widely used in full-duplex systems, future communication and sensing networks, and quantum computing, and it is difficult to implement a passive topology on a chip. Based on switch-based spatio-temporal conductivity modulation, in this study, we design and implement a non-magnetic on-chip passive circulator operating at the Ku band in a 90-nm bulk CMOS technology using a 25% duty-cycle I/Q clock signal. With the virtue of the four-phase non-overlapping clock signal, the proposed circulator achieves a 3.9 dB transmitter (TX)-to-antenna (ANT) and a 4.0 dB ANT-to-receiver (RX) insertion loss with a 1-dB bandwidth of 2.7 GHz (21.4%). The TX-to-RX isolation is better than 17.2 dB, and the TX-to-ANT IIP3 and ANT-to-RX IIP3 are 19.7 dBm and 20.0 dBm, respectively, while occupying a die area of 1.55 mm × 1.15 mm. Although low-cost bulk CMOS technology is used, competitive isolation, linearity performance, and isolation bandwidth are achieved in the proposed design. [ABSTRACT FROM AUTHOR]

The common-source noise-canceling (CSNC) and the gyrator are known for alleviating the trade-off between NF and S11 in wideband LNAs. Moreover, the departure of the input-matching stage and signal-amplifying stage in CSNC facilitates the design of the gyrator. Cascode configuration is exploited to boost the feedback gain, enhancing the gyrator-C effect and broadening the input-matching bandwidth. Therefore, large transistors can be used for noise reduction while maintaining a wide operating bandwidth. Post-layout simulation results in 40 nm CMOS technology show that the circuit achieves an NF of 1.37 dB–1.72 dB while maintaining a wide operation bandwidth of 100 MHz to 3.27 GHz. By contrast, the minimum NF achieved by previously published inductorless wideband LNAs is around 2 dB. Moreover, an S21 of 18.9 dB is obtained, making the design suitable for low NF receivers. Besides, the IIP3 (input third-order intercept point) of −7.1 dBm is obtained, and the circuit consumes 13.1 mW at a 1.2 V voltage supply. Being self-biased, the circuit core consumes only 0.0034 m m 2 area. [ABSTRACT FROM AUTHOR]

Two-ports for mutual transformation between flux-controlled memristors and charge-controlled memristors are proposed. Attention is paid to memristors with the region of negative differential memristance in the charge-flux constitutive relation, when such a transformation should be made carefully. Connections between this transformation, duality rules, and Chua’s table of higher-order elements are described. The proposed transforming cells can be made up of commercially available integrated circuits. Their proper operation is demonstrated via simulations and lab experiments with memristive oscillators.

A novel optical signature and authentication cryptosystem is proposed by applying triangular association encryption algorithm (TAEA) and 3D Arnold transform in Gyrator domains. Firstly, a triangular association encryption algorithm (TAEA) is designed, which makes it possible to turn the diffusion of pixel values within bands into the diffusion within and between bands. Besides, the image signature function is considered and utilized in the proposed cryptosystem. Without the image signature, the original image cannot be restored even if all of the keys are obtained. Moreover, the image integrity authentication function is provided to prevent pixel values from being tampered with. Through the numerical simulation of various types of attacks, the effectiveness and capability of the proposed hyperspectral data signature and authentication cryptosystem is verified. [ABSTRACT FROM AUTHOR]

In inductorless wideband low-noise amplifier (LNA) design, input-matching is traded off with noise figure (NF). The common-source noise-canceling (CSNC) structure and the gyrator alleviate this trade-off, but the corresponding study is insufficient. This work combines the CSNC and gyrator and introduces a three-stage feedback loop to achieve high feedback gain while minimizing the added input capacitance. Hence, the trade-off between NF and input impedance matching is significantly released. Consequently, the lowest NF among inductorless LNAs was achieved, while an operation bandwidth of more than 3 GHz was obtained. Post-layout simulation results in 40 nm CMOS technology show that the circuit achieves an NF of 1.35 dB–1.7 dB while maintaining a wide operation bandwidth of 100 MHz to 3.46 GHz. As far as the author knows, this is the lowest NF inductorless LNAs have achieved. Furthermore, S21 of 10.9 dB and IIP3 (input third-order intercept point) of −5.6 dB m are obtained, and the circuit consumes 14.9 mW at a 1.2 V voltage supply. Being self-biased, the circuit core consumes only 0.0032 m m 2 die area. [ABSTRACT FROM AUTHOR]

Exceptional points of degeneracy (EPD) can enhance the sensitivity of circuits by orders of magnitude. We show various configurations of coupled LC resonators via a gyrator that support EPDs of second and third-order. Each resonator includes a capacitor and inductor with a positive or negative value, and the corresponding EPD frequency could be real or imaginary. When a perturbation occurs in the second-order EPD gyrator-based circuit, we show that there are two real-valued frequencies shifted from the EPD one, following a square root law. This is contrary to what happens in a Parity-Time (PT) symmetric circuits where the two perturbed resonances are complex valued. We show how to get a stable EPD by coupling two unstable resonators, how to get an unstable EPD with an imaginary frequency, and how to get an EPD with a real frequency using an asymmetric gyrator. The relevant Puiseux fractional power series expansion shows the EPD occurrence and the circuit's sensitivity to perturbations. Our findings pave the way for new types of high-sensitive devices that can be used to sense physical, chemical, or biological changes. [ABSTRACT FROM AUTHOR]

We study the rise of exceptional points of degeneracy (EPD) in various distinct circuit configurations such as gyrator-based coupled resonators, coupled resonators with PT-symmetry, and in a single resonator with a time-varying component. In particular, we analyze their high sensitivity to changes in resistance, capacitance, and inductance and show the high sensitivity of the resonance frequency to perturbations. We also investigate stability and instability conditions for these configurations; for example, the effect of losses in the gyrator-based circuit leads to instability, and it may break the symmetry in the PT-symmetry-based circuit, also resulting in instabilities. Instability in the PT-symmetry circuit is also generated by breaking PT-symmetry when one element (e.g., a capacitor) is perturbed due to sensing. We have turned this instability "inconvenience" to an advantage, and we investigate the effect of nonlinear gain in the PT-symmetry coupled-resonator circuit and how this leads to an oscillator with oscillation frequency very sensitive to perturbation. The circuits studied in this paper have the potential to lead the way for a more efficient generation of high-sensitivity sensors that can detect very small changes in chemical, biological, or physical quantities. [ABSTRACT FROM AUTHOR]

A circulator, which is a non-reciprocal device, is widely used in full-duplex systems, future communication and sensing networks, and quantum computing, and it is difficult to implement a passive topology on a chip. Based on switch-based spatio-temporal conductivity modulation, in this study, we design and implement a non-magnetic on-chip passive circulator operating at the Ku band in a 90-nm bulk CMOS technology using a 25% duty-cycle I/Q clock signal. With the virtue of the four-phase non-overlapping clock signal, the proposed circulator achieves a 3.9 dB transmitter (TX)-to-antenna (ANT) and a 4.0 dB ANT-to-receiver (RX) insertion loss with a 1-dB bandwidth of 2.7 GHz (21.4%). The TX-to-RX isolation is better than 17.2 dB, and the TX-to-ANT IIP3 and ANT-to-RX IIP3 are 19.7 dBm and 20.0 dBm, respectively, while occupying a die area of 1.55 mm × 1.15 mm. Although low-cost bulk CMOS technology is used, competitive isolation, linearity performance, and isolation bandwidth are achieved in the proposed design.

Non-reciprocal devices are key elements in modern wireless communication systems. The circulator devices can simultaneously save spectrum resources and antennas. A traditional circulator is made of ferrite materials with an external magnetic bias field, and its bulk and incompatibility with CMOS technology can hardly satisfy the miniaturization and integration of modern high-speed communication systems. In recent years, there have been many outstanding achievements in the study of non-magnetic circulators, among which, the method of producing non-reciprocity by temporal modulation is considered the most likely to have a transformative influence on the industry. By varying one of the parameters of the system with time, the time inversion symmetry of the system can be broken so that the non-reciprocal devices can be formed by applying appropriate topological structures without the use of magnetic materials. In the paper, a new concept of a time-varying phase modulator (TVPM) is proposed to achieve a relatively simple method to break the symmetry of time inversion. Two different time-varying phase modulators and buffering units can be integrated to form a gyrator, with which a circulator can be formed. This paper provides a relatively simple design idea and shows the circuit design and implementation method as well as the numerical analysis and simulation results. The simulation results show that the insertion loss of the circulator at the center frequency is −1.7 dB and the isolation is −18 dB. The proposed non-magnetic circulator shows potential applicability in related 5G and pre-6G systems.

Here, we discuss a model for the quasi-static magnetoelectric (ME) interaction in three-layer composites consisting of a single piezoelectric (PE) layer and two magnetostrictive (MS) layers with positive and negative magnetostriction. Two types of layer arrangements are considered: Type 1: a sandwich structure with the PE layer between the two MS layers and Type 2: the two MS layers form the adjacent layers. Expressions for the ME response are obtained using the system of equations of elasto- and electrostatics for the PE and MS phases. The contributions from longitudinal and bending vibrations to the net ME response are considered. The theory is applied for trilayers consisting of lead zirconate titanate (PZT), nickel for negative magnetostriction, and Metglas for positive magnetostriction. Estimates of the dependence of the strength of the ME response on the thickness of the three layers are provided. It is shown that the asymmetric three-layer structures of both types lead to an increase in the strength of ME interactions by almost an order of magnitude compared to a two-layer piezoelectric-magnetostrictive structure. The model predicts a much stronger ME response in Type 2 structures than in Type 1. The theory discussed here is of importance for designing composites for applications such as magnetic field sensors, gyrators, and energy harvesters.

In this work, we propose, develop, and demonstrate a fundamental and comprehensive theoretical foundation for the first time to formulate and devise known and unknown reciprocal and/or nonreciprocal ferrite components with arbitrarily concurrent multimode features based on the substrate-integrated waveguide (SIW) technology. To achieve such a universal design, a nonreciprocal unit cell (NRUC) is first defined and characterized. Then, an approach is proposed and investigated to deploy a sufficient number of NRUCs next to each other as a kernel multimode SIW topology. The kernel configuration transforms the incident guided-wave into several separate segments, propagating in parallels independently and along each NRUC, which can be manipulated separately. This methodology grants a general solution to forge ferrite components in a multimode configuration, discussed in detail to corroborate the proposed generalized theory. Finally, two multimode components are studied and demonstrated for the first time as application examples for the proposed theory. Namely, a dual-mode circulator and a triple-mode gyrator are prototyped, fabricated, and measured, exhibiting an excellent agreement with simulation results that effectively validate the presented theoretical foundation in this work. [ABSTRACT FROM AUTHOR]

This brief demonstrates the performance of the first active bandpass filter to implement an active inductor in gallium nitride (GaN) technology. Fabrication of the filter and inductor was done using a 0.5 $\mu \text{m}$ pHEMT GaN process with the system implemented on one 2 mm by 2 mm die. The tuning range of the active filter was measured to be 749 MHz at a centre frequency of 3.39 GHz with separate amplitude and quality factor tuning. An amplitude range for S21 was measured to be from −12.2 dB to 13.7 dB within the operating frequency range. Taking advantage of the active inductor’s negative impedance the filter was able to produce a quality factor of 138. On-chip, the active inductor occupies an area of 350 $\mu \text{m}$ by 175 $\mu \text{m}$ compared to approximately 350 $\mu \text{m}$ by 350 $\mu \text{m}$ for their passive counterparts of similar inductance (a 50% decrease in size). The filter was designed for LTE/WLAN applications to demonstrate the capabilities of the active inductor. [ABSTRACT FROM AUTHOR]

A novel optical signature and authentication cryptosystem is proposed by applying triangular association encryption algorithm (TAEA) and 3D Arnold transform in Gyrator domains. Firstly, a triangular association encryption algorithm (TAEA) is designed, which makes it possible to turn the diffusion of pixel values within bands into the diffusion within and between bands. Besides, the image signature function is considered and utilized in the proposed cryptosystem. Without the image signature, the original image cannot be restored even if all of the keys are obtained. Moreover, the image integrity authentication function is provided to prevent pixel values from being tampered with. Through the numerical simulation of various types of attacks, the effectiveness and capability of the proposed hyperspectral data signature and authentication cryptosystem is verified.

A detailed analysis of an operational transconductance amplifier based gyrator implementing a fractional-order inductance simulator is presented. The influence of active element non-ideal properties on the gyrator operation is investigated and demonstrated by admittance characteristics and formulas for important values and cut-off frequencies in these characteristics. Recommendations to optimize the performance of the gyrator in terms of operation bandwidth, the range of obtainable admittance magnitude, and signal dynamic range are proposed. The theoretical observations are verified by PSpice simulations of the gyrator with LT1228 integrated circuit. [ABSTRACT FROM AUTHOR]

Advances in semiconductor devices have allowed researchers to explore temporal modulation as a means to achieve nonreciprocity. This is of practical importance, since nonreciprocity is often desired in electronic systems that are incompatible with the integration of magnetic materials. Recently, $N$ -path networks, a class of electronic systems, whose behavior was first introduced in the 1950s, have been shown to allow nonreciprocity. An analysis technique was introduced by Krishnaswamy et al. in 2016 to analytically characterize an $N$ -path network, used in the implementation of a microwave circulator. In general, the technique enables the analysis of $N$ -path networks that consist of first-order circuits. However, the extension of the technique to $N$ -path networks with higher-order internal circuits is unclear. Meanwhile, commercial harmonic balance solvers often fail to converge when the excitation frequency is close to the frequency of modulation. In this article, we develop an efficient, semianalytical technique for analyzing $N$ -path networks. The benefits of the analysis technique presented are that it converges for all excitation frequencies, the simulation time is independent of the number, $N$ , of paths, and it can be used to simulate the performance of complicated, higher-order internal networks. [ABSTRACT FROM AUTHOR]

Abstract Stimulated by the recent implementation of a three-port Hall-effect microwave circulator of Mahoney et al. (MEA), we present model studies of the performance of this device. Our calculations are based on the capacitive-coupling model of Viola and DiVincenzo (VD). Based on conductance data from a typical Hall-bar device obtained from a two-dimensional electron gas (2DEG) in a magnetic field, we numerically solve the coupled field-circuit equations to calculate the expected performance of the circulator, as determined by the S parameters of the device when coupled to 50Ω ports, as a function of frequency and magnetic field. Above magnetic fields of 1.5 T, for which a typical 2DEG enters the quantum Hall regime (corresponding to a Landau-level filling fraction ν of 20), the Hall angle θH=tan−1σxy/σxx $\theta_{H}=\tan^{-1}\sigma_{xy}/\sigma_{xx}$ always remains close to 90°, and the S parameters are close to the analytic predictions of VD for θH=π/2 $\theta_{H}=\pi/2$. As anticipated by VD, MEA find the device to have rather high (kΩ) impedance, and thus to be extremely mismatched to 50Ω, requiring the use of impedance matching. We incorporate the lumped matching circuits of MEA in our modeling and confirm that they can produce excellent circulation, although confined to a very small bandwidth. We predict that this bandwidth is significantly improved by working at lower magnetic field when the Landau index is high, e.g. ν=20 $\nu=20$, and the impedance mismatch is correspondingly less extreme. Our modeling also confirms the observation of MEA that parasitic port-to-port capacitance can produce very interesting countercirculation effects.

This paper presents a three-port three-phase current-fed dc–dc converter with high-frequency isolation and bidirectional power flow. Port I is fed by a battery bank, port II employs a set of photovoltaic modules, and port III is connected to a dc link. The topology uses three single-phase H-bridge cells in the primary side and a three-phase H-bridge converter in the secondary one. High-frequency isolation is ensured by three single-phase transformers connected in an open delta-wye configuration. The theoretical analysis is performed considering the fundamental component of the voltage across the transformers. Maximum power point tracking, the battery current, and the power flow between the primary and secondary sides are controlled by the use of variable duty cycle technique in the primary side and the use of phase-shift technique between the primary and secondary bridges. In order to validate the study, experimental results of the proposed system considering the dc rated voltages as 48 V/96 V/380 V for Ports I/II/III, respectively, and rated power of 3.5 kW are carried out. [ABSTRACT FROM AUTHOR]

Magnetoelectric (ME) gyrators are unique circuit elements capable of direct conversion of the current to voltage or vice versa. In order to understand the power conversion and loss processes in the gyrators, an equivalent input loss factor has been developed in this paper based on Mason's model (equivalent circuit model). This factor serves to understand the loss transferring mechanism and to evaluate the conversion efficiency for the electric power in ME gyrators. Studies have been carried out for modeling the power conversion in both the solenoid and the ME core. Several important factors have been proposed and discussed to enhance the conversion efficiencies in the electric–magnetic–mechanical three-phase conversion process. A simplification of our equations reveals that the efficiency of the ME gyrator is related to the product of the effective coupling (k2 $_{\text{eff, m}}$) and mechanical quality (Qmech). According to our model, magnetic and electric materials with highk $_{\text{eff, m}}$ andQmechvalues are the key ingredients to enhance the efficiency of ME gyrators. We have successfully realized a power efficiency of 92% based on a Metglas/hard-PZT ME gyrator, which showed a good correlation to the predicted values. [ABSTRACT FROM AUTHOR]

This paper reviews gyrator based Gm-C filters and their characteristics. The most common gyrator based Gm-C filter architecture is described. Different types of gyrator biquad are presented as well as the properties of simulated inductor in them are outlined. The circuit of fully differential OTA is considered and analyzed in more details. The key OTA parameters related to gyrator based Gm-C filters are presented. Moreover, different techniques for improvement the performance of OTAs is considered. This paper also includes a comparison between single stage and multiple stage OTA with respect to frequency dependence of Gm. Finally, gyrator based Gm-C filters applications for the frequency range starting from few Hz up to several hundred of MHz are summarized. [ABSTRACT FROM AUTHOR]

A detailed analysis of an operational transconductance amplifier based gyrator implementing a fractional-order inductance simulator is presented. The influence of active element non-ideal properties on the gyrator operation is investigated and demonstrated by admittance characteristics and formulas for important values and cut-off frequencies in these characteristics. Recommendations to optimize the performance of the gyrator in terms of operation bandwidth, the range of obtainable admittance magnitude, and signal dynamic range are proposed. The theoretical observations are verified by PSpice simulations of the gyrator with LT1228 integrated circuit.

The paper investigates the behavior of unidirectional two-port equivalent circuit composed of an electronic gyrator with Antoniou operational amplifier and a reciprocal two-port built by a transversal resistance (RT). From the analysis of two-port equations standpoint, by correct choice of circuit conductance, the two-port can operate as an ideal or a lossy gyrator. Due to the interest in practical aspects of energy transfer from one terminal to other, an analysis of the two-port parameters for the unidirectional circuit diagram is performed. The validity of the tested circuit results obtained analytically and through numerical simulation PSpice has been verified experimentally, in two cases, with equal and different transfer conductance.

Magnetic-resonant wireless power transfer (WPT) has become a reliable contactless source of power for a wide range of applications. WPT spans different power levels ranging from low-power implantable devices up to high-power electric vehicles (EV) battery charging. The transmission range and efficiency of WPT have been reasonably enhanced by resonating the transmitter and receiver coils at a common frequency. Nevertheless, matching between resonance in the transmitter and receiver is quite cumbersome, particularly in single-transmitter multi-receiver systems. The resonance frequency in transmitter and receiver tank circuits has to be perfectly matched, otherwise power transfer capability is greatly degraded. This paper discusses the mistuning effect of parallel-compensated receivers, and thereof a novel dynamic frequency tuning method and related circuit topology and control is proposed and characterized in the system application. The proposed method is based on the concept of switch-mode gyrator emulating variable lossless inductors oriented to enable self-tunability in WPT receivers. [ABSTRACT FROM AUTHOR]

In this paper, an accurate front-end CMOS interface circuit for sensing very small capacitance changes in capacitive sensors is presented. The proposed structure scales capacitance variation to the sensible impedance changing. The scaling factor of the circuit can be easily tuned by adjusting bias points of the transistors. In order to cancel or decrease the parasitic components, the RC feedback and input transistor cascading techniques are employed in the design. To simulate the circuit, HSPICE simulator is utilized to verify the validity of the theoretical formulations in 0.18 $$\upmu \hbox {m}$$ technology. According to schematic and post-layout simulation results, input impedance changes linearly versus capacitance variations up to 0.7 GHz, while the sensor capacitance changing is varied between 0 and 200 fF. According to the simulation results, total dc power consumption is obtained as low as 1 mW with 0.9 V power supply. [ABSTRACT FROM AUTHOR]