Middle range wireless power transfer systems with multiple resonators

The equivalent two-port network model of a middle range wireless power transfer(WPT) system was presented based on strongly coupled multiple resonators. The key parameters of the WPT system include self-inductance, resistance, parasitic capacitance, mutual inductance and S-parameters of coils & resonators were analyzed. The impedance matching method was used to optimize load power and transmission efficiency of the multi-resonator WPT system, and the impedance matching method was realized through adjusting the distances between the coils and resonators. Experiments show that the impedance matching method can effectively improve load power and transmission efficiency for middle range wireless power transfer systems with multiple resonators, at distances up to 3 times the coil radius with efficiency more than 70% and load power also close to 3.5 W.

Analytical Criteria for Local Activity of CNN with Two Ports and Application to Smoothed Chua's Circuit

Presents analytic criteria for the local activity theory in two-port cellularneural network (CNN) cells with four local state variables, and gives the application to a smoothedChua's circuit (SCC) CNN with two-port and I 5 S 15 arrays. The bifurcation diagrams of the SCC CNNshow that they are completely the same as those of an SCC CNN with one-port calculated earlier;which do not exist locally passive domain. The evolution of the patterns of the state variables ofthe SCC CNN is stimulated. Oscillatory patterns, chaotic patterns, or divergent patterns may emergeif the selected cell parameters are located in the locally active unstable domains but nearby theedge of chaos domain.

A Large Dynamic Range Floating Memristor Emulator With Equal Port Current Restriction

In this paper, a large dynamic range floating memristor emulator(LDRFME) with equal port current restriction is proposed to be achieved by a large dynamic range floating voltage-controlled linear resistor(VCLR). Since real memristors have not been largely commercialized until now, the application of a LDRFME to memristive systems is reasonable. Motivated by this need, this paper proposes an achievement of a LDRFME based on a feasible transistor model. A first circuit extends the voltage range of the triode region of an ordinary junction field effect transistor(JFET). The idea is to use this JFET transistor as a tunable linear resistor. A second memristive non-linear circuit is used to drive the resistance of the first JFET transistor. Then those two circuits are connected together and, under certain conditions, the obtained "resistor" presents a hysteretic behavior,which is considered as a memristive effect. The electrical characteristics of a LDRFME are validated by software simulation and real measurement, respectively.

Effluent Discharges from Two Outfalls on a Sloping Beach

A marine outfall is a long pipeline that continuously discharges large amounts of effluent streams into the sea. As the number of marine outfalls along the coastal areas is growing, a far field mathematical model with two point sources on a sloping beach is used to assess the coastal water quality following discharges from two outfalls. Asymptotic approximation will be made to the concentration at the beach to measure how well the effluent plumes are mixed and diluted in the coastal waters. The result found agrees with the engineering practice of installing a two-port diffuser at the end of a single outfall to minimize its potential environment impacts.

Development of two-port surface acoustic wave resonator with Al/Au electrodes for gas sensing

Simple and efficient surface acoustic wave （SAW） two-port resonators with low insertion loss and high Q-values on ST-X quartz substrate using a corrosion-proof A1/Au-stripe electrode structure are developed for gas sensing. It was composed of two shorted grating reflectors and adjacent intedigital transducers （IDT）, and an active metal film in the cavity between the IDTs for the sensitive film coating. The devices are expected to provide good protection towards metal electrode for gas sensors application in chemically reactive environments. Excellent device performance as low insertion loss, high Q factor and single-mode are achieved by carefully selecting the metallic electrode thickness, cavity length and acoustic aperture. Prior to fabrication, the coupling of modes （COM） model was performed for device simulation to determine the optimal design parameters. The fabricated single-mode SAW resonator at operation frequency of 300 MHz range exhibits matched insertion loss of ~6.5 dB and loaded Q factor in the 3000 range. Using the fabricated resonator as the feedback element, a duaresonator-oscillator with excellent frequency stability （0.1 ppm） was developed and evaluated experimentally, and it is significant for performance improvement of SAW gas sensor.

The noise matrix theory of two-port network--The noise analysis of a feedback amplifier

THE low-noise preamplifier, as one of the major circuits in signal detection system, consists ofthe low noise amplifier and the feedback network. The low noise amplifier design aims both tocalculate the optimal source impedance and minimum noise figure, and to compare the noiseperformance and other characteristics of variant circuits and components. The conventional ap-proach to noise analysis of an electronic circuit is to calculate the output noise power of the

Time-domain and Frequency-domain Analyses of PETT Oscillation in Press Pack IGBTs

Plasma extraction transit time(PETT)oscillation might appear in IGBT devices,which is harmful to the electromagnetic compatibility(EMC)of a renewable energy system.To eliminate this oscillation,its frequency-domain characteristics in wire-bonded IGBT devices have been extensively studied.However,the time-domain analysis of PETT oscillation,especially in Press Pack IGBT(PPI)devices,has not attracted enough attention yet.In this paper,PETT oscillations with multi-chips in PPI devices are systematically investigated by experiments.It is first reported there are multiple resonant oscillations at the tail period when multi-chips turn off.Oscillations overlap in the time domain waveforms,which lead PETT oscillation to be more serious in multi-chips.Then,PETT oscillation is divided into three different feedback states for the first time.For the IGBT chip in the PETT oscillation,its physical based model and behavior model are proposed,which further form the equivalent circuit as the two-port network.Moreover,it is indicated that only parallel resonances can lead to PETT oscillation,which is consistent with experiment results.

Analysis and optimization of TSV–TSV coupling in three-dimensional integrated circuits

Through silicon via （TSV）-TSV coupling is detrimental to the performance of three-dimensional （3D） integrated circuits （ICs） with the major negative effect of introducing coupling noise. In order to obtain an accurate estimation of the coupling level from TSV-TSV in the early design stage, this paper first proposes an impedance- level model of the coupling channel between TSVs based on a two-port network, and then derives the formula of the coupling coefficient to describe the TSV-TSV coupling effect. The accuracy of the formula is validated by comparing the results with 3D full-wave simulations. Furthermore, a design technique for optimizing the coupling between adjacent coupled signal TSVs is proposed. Through SPICE simulations, the proposed technique shows its feasibility to reduce the coupling noise for both a simple TSV-TSV circuit and a complicated circuit with more TSVs, and demonstrates its potential for designers in achieving the goal of improving the electrical pertbrmance of3D ICs.

A simple method of measuring differentially-excited on-wafer spiral inductor-like components

This paper proposes a simple method of measuring differentially-excited on-wafer RF CMOS spiral inductor-like components.This method requires only two common ‘G-S-G＇ probes and an ordinary two-port VNA.Using a network instead of a detailed equivalent circuit, this method completes the de-embedding with only one ‘Through＇ dummy, and thus the measurements are greatly simplified.By designing the ports ‘Open＇ or ‘Shortcircuited＇ deliberately, a multi-port transformer can be transformed into three two-port networks with different terminators.Then, couplings between the two coils can be solved, and the differentially-excited scattering parameters（S-parameters） can be constructed.Also, a group of differential inductors and transformers were designed and measured, and then comparisons between simulated and measured electromagnetic results are performed to verify this method.

Two different LNA optimizing techniques

Two different LNA design techniques,namely the classical two-port technique and the Shaeffer technique, have been introduced,compared and implemented for practical design.Their merits and drawbacks are also discussed.This paper mainly focuses on the former technique,which is seldom introduced in traditional papers. Since a parasitic capacitor of the transistor is included in the computation of the former technique,the errors caused by the ignorance of the capacitor have been minimized,which is superior to traditional techniques.Using the former technique,a fully integrated LNA is realized with only 1.4 dB while drawing 1.3 mA DC at 2.4 GHz for simulation results.Another version of the LNA is designed using the latter technique,which has been fabricated.

A vertically integrated capacitorless memory cell

A two-port capacitorless PNPN device with high density,high speed and low power memory fabricated using standard CMOS technology is presented.Experiments and calibrated simulations were conducted which prove that this new memory cell has a high operation speed（ns level）,large read current margin（read current ratio of 10~4×）,low process variation,good thermal reliability and available retention time（190 ms）.Furthermore,the new memory cell is free of the cyclic endurance/reliability problems induced by hot-carrier injection due to the gateless structure.