Features and Prototypes of HTS High Q Resonant Circuit

High Te superconductor （HTS） technology has been used to develop a unique high Q resonant circuit. Such circuit or device has some special characteristics such as very high voltage generation. Theoretical study and experimental approaches have proceeded for the concept verification. This paper presents the theory about this high Q resonant circuit. The operation principle of the circuit is described. A practical prototype for HTS high voltage generation is also demonstrated. The experiment result shows that very high voltages can be achieved by the developed method using HTS technology.

Quantum fluctuations of mesoscopic damped double resonance RLC circuit with mutual capacitance-inductance coupling

Based on the scheme of damped harmonic oscillator quantization and thermo-field dynamics （TFD）, the quantization of mesoscopic damped double resonance RLC circuit with mutual capacitance-inductance coupling is proposed. The quantum fluctuations of charge and current of each loop in a squeezed vacuum state are studied in the thermal excitation case. It is shown that the fluctuations not only depend on circuit inherent parameters, but also rely on excitation quantum number and squeezing parameter. Moreover, due to the finite environmental temperature and damped resistance, the fluctuations increase with the temperature rising, and decay with time.

ANALYSIS OF A NEW SOFT SWITCHING PWM INVERTER

Resonant dc link inverter is a zero voltage switching inverter.This paper proposes a new cascade resonant dc link inverter that consists of two power converter units,a rugged resonant dc link and an inverter bridge.A detailed analysis of the soft switching process in the rugged resonant dc link and the realization of pulse width modulation (PWM) control strategy in the inverter bridge are presented in the paper. The operation modes, the input and output features and the interface between the rugged resonant dc link and the inverter bridge are also discussed. The relationship between the circuit features and the parameters is deduced, which provides a theoretical base for the circuit design. The analysis results show that the rugged resonant dc link can be regulated by open-loop control and the control of the rugged resonant dc link is independent of that of the inverter bridge, which makes the inverter control easy and realizable.The circuit of the inverter is simulated with a standard circuit simulation program PSPICE. The simulation results are corresponding to the predicted ones of the circuit analysis.

Tunable optical filter using second-order micro-ring resonator

In this paper, we design and fabricate a silicon integrated optical filter consisting of two cascaded micro-ring resonators and two straight waveguides. Two micro-heaters are fabricated on the top of two micro-rings respectively, which are employed to modulate the micro-rings to perform the function of a tunable optical filter by the thermo–optic effect. The static response test indicates that the extinction ratio and 3-d B bandwidth are 29.01 d B and 0.21 nm respectively, the dynamic response test indicates that the 10%–90% rise and 90%–10% fall time of the filter are 16 μs and 12 μs, respectively,which can meet the requirements of optical communication and information processing. Finally, the power consumption of the device is also characterized, and the total power consumption is about 9.43 m W/nm, which has been improved efficiently.

Two Kinds Equal Frequency Circuits to Achieve Locally Resonant Band Gap of a Circular Plate Attached Alternately by Piezoelectric Unimorphs

A circular thin plate is proposed for vibration attenuation,which is attached alternately by annular piezoelectric unimorphs with resonant shunt circuits.Two kinds of equal frequency resonant shunt circuits are designed to achieve an integrated locally resonant（LR）band gap（BG） with a much smaller transmission factor：（1） the structure is arrayed periodically while the resonant shunt circuits are aperiodic;（2） the resonant shunt circuits are periodic while the structure is aperiodic.The transmission factor curve is calculated,which is validated by the finite element method.Dependences of the LR BG performance upon the geometric and electric parameters are also analyzed.

High-Q micro-ring resonators and grating couplers for silicon-on-insulator integrated photonic circuits

An ultra-small integrated photonic circuit has been proposed,which incorporates a high-quality-factor passive micro-ring resonator（MR） linked to a vertical grating coupler on a standard silicon-on-insulator（SOI） substrate.The experimental results demonstrate that the MR propagation loss is 0.532 dB/cm with a 10μm radius ring resonator,the intrinsic quality factor is as high as 202.000,the waveguide grating wavelength response curve is a 1 dB bandwidth of 40 nm at 1540 nm telecommunication wavelengths,and the measured fiber-to-fiber coupling loss is 10 dB.Furthermore,the resonator wavelength temperature dependence of the 450 nm wide micro-ring resonator is 54.1 pm/℃.Such vertical grating coupler and low loss MR-integrated components greatly promote a key element in biosensors and high-speed interconnect communication applications.

A Novel Readout System for Wireless Passive Pressure Sensors

This paper presents a novel readout system for wireless passive pressure sensors based on the inductively coupled inductor and cavity （LC） resonant circuits. The proposed system consists of a reader antenna inductively coupled to the sensor circuit, a readout circuit, and a personal computer （PC） post processing unit. The readout circuit generates a voltage signal representing the sensor＇s capacitance. The frequency of the reader antenna driving signal is a constant, which is equal to the sensor＇s resonant frequency at zero pressure. Based on mechanical and electrical modeling, the pressure sensor design based on the high temperature co-fired ceramic （HTCC） technology is conducted and discussed. The functionality and accuracy of the readout system are tested with a voltage-capacitance measurement system and demonstrated in a realistic pressure measurement environment, so that the overall performance and the feasibility of the readout system are proved.

A readout system for passive pressure sensors

This paper presents a readout system for the passive pressure sensors which consist of a pressure- sensitive capacitor and an inductance coil to form an LC circuit. The LC circuit transforms the pressure variation into the LC resonant frequency shift. The proposed system is composed of a reader antenna inductively coupled to the sensor inductor, a measurement circuit, and a PC post-processing unit. The measurement circuit generates a DC output voltage related to the sensor＇s resonant frequency and converts the output voltage into digital form. The PC post-processing unit processes the digital data and calculates the sensor＇s resonant frequency. To test the performance of the readout system, a sensor is designed and fabricated based on low temperature co-fired ceramic （LTCC）, and a series of testing experiments is carried out. The experimental results show good agreement with the impedance analyzer＇s results, their error is less than 2.5%, and the measured values are almost insensitive to the variation of readout distance. It proves that the proposed system is effective practically.

Stochastic resonance in an optical bistable system subjected to cross-correlated additive white noise and multiplicative colored noise

The stochastic resonance （SR） of an optical bistable system with cross-correlated additive white and multiplicative colored noises and periodic signal is studied using the unified colored noise approximation and the theory of signal-to-noise ratio （SNR）. Results show that cross-correlation intensity λ enforces the SR of the system. The position of the peak on the SNR-τ curves moves to the right direction along with the increase of λ （τ is the self-correlation time of the multiplicative colored noise）. We find the SR phenomenon in the SNR-D and SNR-Q curves （D and Q are the intensities of the additive and multiplicative noises, respectively）, but not in the SNR-λ curves.