A 1.8-2.6 GHz CMOS VCO with switched capacitor array and switched inductor array

The design of a 1.76-2.56 GHz CMOS voltage-controlled oscillator(VCO)with switched capacitor array and switched inductor array is presented.Fabricated in 0.18μm 1P6M CMOS technology,the VCO achieves a 37% frequency tuning range.The measured phase noise varies between-118.5 dBc/Hz and-122.8 dBc/Hz at 1 MHz offset across the tuning range.Power consumption is about 14.4 mW with a 1.8 V supply.Based on a reconfigurable LC tank with switched capacitor array and switched inductor array,the mnmg range is analyzed and derived in terms of design parameters,yielding useful equations to guide the circuit design.     

Novel capacitor floatation scheme

An earlier suggested ideal floating inductor realisation circuit is extended to a capacitor floatation scheme with the addition of only one operational amplifier. Appropriate comments regarding practical realisability of both floating capacitor and inductor are appended.     

MEMS-Based Tunable LC Bandstop Filter With an Ultra-Wide Continuous Tuning Range

This letter presents a new microelectromechanical system-based tunable LC filter that utilizes a tunable capacitor and a tunable inductor in a single device. An electrically floating metal plate is located between the tunable capacitor and the tunable inductor. As the floating metal plate is thermally moved and used commonly for both the capacitor and inductor, the device provides an ultra-wide continuous frequency tuning range by a simultaneous increase or decrease of the capacitance and inductance. The fabricated tunable LC filter showed a continuous frequency tuning ratio in excess of 127% in a range of 8.8 GHz to more than 20 GHz.      

A Novel Low-Power Logic Circuit Design Scheme

This brief proposes a novel low-power digital logic design scheme based on the energy exchange in the switched inductor-capacitor (SLC) circuit. It presents a design paradigm which in ideal case may lead to a circuit capable of performing logic operations with no switching losses. In traditional integrated circuit design, the energy is stored in the output load capacitor through a pull-up path (corresponding to storing a logic 1). When the output changes its logic value, this stored energy is dissipated through the pull down path to the ground. In order to reduce this switching energy dissipation each time the load capacitor is discharged, we store its energy in the magnetic field of the inductor in the proposed SLC architecture. Whenever the output load needs to be charged again, we transfer the energy back from the inductor to the load capacitor. This significantly reduces the switching energy. We illustrated the operation of the SLC architecture through SPICE simulation. A brief discussion of some practical considerations for this architecture is also presented     

低温共烧陶瓷埋置电感和电容的研究

讨论了低温共烧陶瓷(LTCC)埋置电感、电容的几何结构,并进行仿真,分析了结构变化对电感性能的影响,并进行实验制作,通过测试样品以验证仿真结果。仿真结果中找到的规律有效的节省了器件设计的时间,为等效模型的提取和元件库的建立奠定了一定的基础。     

New canonic active RC realizations of grounded and floating inductors

Two new canonic active RC networks are proposed for the simulation of grounded and floating lossy inductors. A grounded inductor is simulated with one operational amplifier, four resistors and one grounded capacitor. The circuit for a floating inductor employs two amplifiers, six resistors, and only one capacitor.     

Analysis and Design Optimization of Diode Front-End Rectifier Passive Components for Voltage Source Inverters

This paper presents a systematic design optimization approach for inductors and capacitors in diode front-end rectifiers for voltage source inverters. Analytical relationships between various design variables, operating conditions, and performance and physical constraints are established under nominal, overload, and inrush conditions. A new method to analytically calculate the inrush current is developed considering the nonlinear characteristics of the inductor core materials. A design optimization program based on the established analytical relationships and a genetic algorithm is developed. Examples show that the optimization process can lead to a smaller/lower cost inductor and capacitor design. Experiments are conducted to verify key analytical relationships and the optimized design.      

Analysis, design, and implementation of an active clamp forward converter with synchronous rectifier

The system analysis, circuit design, and implementation of active clamp based forward converter with synchronous rectifier are presented in this paper. To release the energy stored in the leakage inductor and to minimize the spike voltage at the transformer primary side, active clamp circuit included one clamp switch and one clamp capacitor is adopted in the circuit. Based on the partial resonance with the output capacitor of switch and the leakage inductor of transformer, the main switch is turned on at zero voltage switching (ZVS). The clamp switch is also operated at ZVS operation based on the resonance of leakage inductor and clamp capacitor. The synchronous switches are used at the secondary side to further reduce the conduction losses. The experimental results based on the laboratory prototypes are presented to verify the circuit performance.     

基于RLC串联谐振实现电感的测量

介绍了一种测量电感的新方法,以RLC串联谐振电路为基础,将待测电感与电阻、电容串联起来组成RLC振荡电路;当电路达到谐振状态时,当电容已知,可得待测电感的值。此方法测量原理简单,操作方便,测量结果精确度较高,值得推广。     

Engineering design of lossless passive soft switching methods for PWM converters. II. With nonminimum voltage stress circuit cells

This paper proposes the analysis and design methodology of lossless, passive soft switching methods for PWM converters. The emphasis of the design and analysis is for PWM converters that use nonminimum voltage stress (non-MVS) circuit cells to provide soft switching. PWM converters with non-MVS circuit cells have several distinct advantages over converters that use minimum voltage stress (MVS) cells. With the same relative size of the inductor and capacitor added for soft switching, the non-MVS cells have a substantially larger duty ratio range where soft switching is guaranteed. In addition, the overcurrent stress of the main switch, under most conditions, will be lower and an optimum value of inductor and capacitor added for soft switching can be used. Therefore, with proper design, the non-MVS cells provide higher efficiency. These advantages are obtained with the price of higher switching voltage stress and one additional inductor. The loss model for a MOSFET and optimum capacitor and inductor values are utilized in the design procedure. Examples of the design procedure are given for PFC and DC-DC applications. Experimental results backup the claim of higher efficiency.     

Switched-capacitor simulation of grounded inductors using operational-amplifier pole

A simulation of a grounded inductor using a switched capacitor and the pole of an operational amplifier is presented. The simulation inductor has good high-frequency and Q performance.     

单片集成直流-直流转换器的效率提高方法

采用SMIC 0.13μm CMOS工艺,设计实现了开关频率达到250 MHz,单片集成的降压型电源转换器。为了提高电源转换效率,该转换器中的片上电感采用非对称性设计方法,提高了电感的品质因数。采用了高密度片上滤波电容来稳定输出电压,同时对单位电容尺寸的优化设计减小了电容的等效串联电阻以及输出电压纹波。测试结果表明,芯片输入电压为3.3 V,当输出2.5 V电压时,峰值效率达到了80%,最大输出电流达到270 mA;当输出1.8 V电压时,峰值效率达到了70%,最大输出电流达到400 mA。     

红外遥控接收器中带通滤波器的设计

红外遥控接收器的应用非常广泛,而带通滤波器是红外遥控接收器芯片中的一个重要的模块.滤波器的实现通常需要电感,而电感是很难集成到集成电路中的,本文介绍一种利用放大器和电容实现有源电感的方法.     

A magnetically coupled regenerative turn-on and turn-off snubberconfiguration

This paper presents a magnetically coupled regenerative turn-on and turn-off snubber configuration applied to a boost converter, which operates in continuous conduction mode (CCM). In addition to reducing the stresses in the switch, providing soft transitions in its turn-off voltage and turn-on current, it transfers the energy stored in the snubber capacitor to the load. This is achieved by using a coupled inductor mounted on the main inductor of the converter, which resets the capacitor voltage at each switching period. Design equations, as well as experimental results are presented, showing the high performance of the boost converter using the proposed snubber     

The rotator—A new network component

This paper presents a new linear, reciprocal, active two-port network element called a rotator, of which there are three types: an R- rotator, an L-rotator, and a C-rotator. They have the unique property that whenever a nonlinear resistor, inductor, or capacitor is connected to one port of an R-, L-, or C-rotator, respectively, the resulting two-terminal network behaves as a new resistor, inductor, or capacitor whose characteristic curve is that of the original resistor, inductor, or capacitor, rotated by a prescribed angle about the origin. The rotator is realizable by either a π-network or a T-network of linear resistances, inductances, or capacitances. It can also be realized by a balanced lattice network of linear elements. Operational laboratory models are reported, and experimental data agree remarkably well with theoretical predictions. The sensitivity, power rating, and stability performances of rotators are considered in detail in this paper, and practical stability criteria are given. They are shown to be indispensable building blocks for realizing multivalued elements, and some potential applications are described.     

An wide-range tunable on-chip radio-frequency LC-tank formed with a post-CMOS-compatible MEMS fabrication technique

An on-chip-micromachined tunable LC-tank, which consists of a metal inter-digitated variable capacitor and a metal solenoid inductor, is developed for wide-range radio-frequency (RF) tuning in multi-GHz band. A low-temperature metal MEMS process is developed to on-chip fabricate the passives. The process can be used for post-CMOS-compatible integration with RF ICs. Both the varactor and the inductor are suspended with a gap from the low-resistivity silicon wafer (i.e. standard CMOS wafer) for effectively depressing RF loss. The fabricated variable capacitor part, the inductor part and the whole tunable LC resonator are sequentially tested, finally resulting in a wide resonance-frequency tuning range of 72% (between about 3.5 and 6.0 GHz) under a low tuning voltage range of 0-4 V, while the Q-factor ranged within 23 and 8.     

A low power tunable inductor based on active capacitor with negative resistance

A method to provide a low power tunable inductor is presented in which the inductance and its equivalent series resistance can be independently tuned. This equivalent series resistance can be also set to negative or zero value that is corresponding to inductor with ideal quality factor. In this method, a varactor is placed in parallel with a passive inductor and then, an active capacitor is placed in series with them. To this end, a low power Tunable Active Capacitor (TAC) is proposed which is capable of generating tunable capacitor and large negative resistance to compensate the loss of tunable inductor circuit. Also, the power consumption is low because of using a diode-connected transistor. A prototype of the proposed circuit is designed and simulated at 4 GHz. The electromagnetic simulation results show the inductance tuning range of 0.48–2.3nH with zero or even negative equivalent series resistance is obtained while the power dissipation is less than 3 mW. Moreover, noise analysis shows that higher inductance translates to lower noise while there is a weak correlation between noise and quality factor of the obtained inductances.     

A simple CMOS-based inductor simulator and frequency performance improvement techniques

In this paper, a new CMOS grounded positive tunable inductor simulator based on using two simple CMOS transconductors and an inverting amplifier is presented. The introduced inductor simulator uses a grounded capacitor; accordingly, it is suitable for integrated circuit (IC) fabrication. In addition a CMOS circuit for realizing negative tunable resistor which can be used for parasitic cancellation in inductor simulators and consequently enhancing their frequency performances is developed. A novel method for providing high-frequency performance improvement of simulated inductors is also introduced. Simulation and experimental results are given to demonstrate the performance of the developed inductor simulator and validity of the proposed frequency performance improvement method.     

Investigating an LCL load resonant inverter for inductive power transfer applications

A inductor/capacitor/inductor load resonant inverter is investigated for inductive power transfer applications. The inverter uses a variable frequency controller and operates in discontinuous current mode. The steady state operation of this system is determined by a power flow balance between the inverter and the resonant tank. The results are used to design a system to achieve maximum power transfer.     

Small antennas

A small antenna is one whose size is a small fraction of the wavelength. It is a capacitor or inductor, and it is tuned to resonance by a reactor of opposite kind. Its bandwidth of impedance matching is subject to a fundamental limitation measured by its "radiation power factor" which is proportional to its "effective volume". These principles are reviewed in the light of a quarter-century of experience. They are related to various practical configurations, including flush radiators for mounting on aircraft. Among the examples, one extreme is a small one-turn loop of wide strip, tuned by an integral capacitor. The opposite extreme is the largest antenna in the world, which is a "small antenna" in terms of its operating wavelength. In each of these extremes, the radiation power factor is much less than one percent.