Modeling of power distribution systems for high-performancemicroprocessors

This paper presents approximate techniques for building models and simulating the response of power distribution systems for high-performance microprocessors. Several distributed equivalent SPICE circuit models were built by extracting the appropriate resistance, inductance, capacitance (RLC) component values using a combination of two-dimensional (2-D) and three-dimensional (3-D) quasi-static field solvers. They were used to assess how well such effects as system transfer impedance and transient characteristics can be predicted. The models include the chip, its controlled collapsed chip connection (C4) connections to the package, the power distribution structure in the package, connector and motherboard. It is found that the response of the entire power system can be treated as a second order system, by which the main features of the performance of the power delivery network are assessed. Samples of transient and frequency domain data for typical microprocessors are given and the effects of some design options are discussed, as are the tradeoffs in model complexity versus the gain of useful design information     

基于配电系统节电器的谐波抑制研究

模拟配电网用户侧典型负荷组成,搭建了节电器节电行为研究平台.通过电能质量分析仪、三相可编程电源等在线监测与分析仪器,研究了配电系统节电器在阻感负荷运行工况下对负荷侧电网谐波的抑制行为.结果表明,配电系统节电器抑制电力用户侧谐波效果明显,单相电流谐波可降低2％ ～5％,波型稳定,电能质量得到有效提高.     

Modified Wilkinson power divider for nth harmonic suppression

This paper presents a structure of the Wilkinson power divider that can suppress the nth harmonic output. The power divider consists of two /spl lambda//4n open stubs, which are located at the center of /spl lambda//4 branches and a parallel connection of a resistor and an inductor, which shunts the output ports. Experimental results show that this power divider suppresses the third harmonic component to less than -40 dB, while maintaining the characteristics of a conventional Wilkinson power divider; featuring an equal power split, a simultaneous impedance matching at all ports and a good isolation between output ports. These results agree quite well with the simulation results.     

A novel active power filter for reactive power compensation and harmonic suppression

A new single-phase active power filter for reactive power compensation and harmonic suppression is proposed. Besides the general performance of other active power filters, it also has the feature that it can maintain the mains current as a sine-wave and correct the displacement power factor close to unity even when the mains voltage is distorted. A prototype of this active power filter is developed and tested under rectifier load to verify its performance. The test results show that the proposed scheme can compensate the reactive power and suppress harmonics of the nonlinear load effectively.     

Modified design of Wilkinson power divider for harmonic suppression

A modified design that can reject the nth harmonic output in the Wilkinson power divider is presented. After adding transmission lines between the resistor and each output port of the traditional design, a solution of the modified Wilkinson divider can be found. Experimental results show the third harmonic suppression to be -37.0 dB, while maintaining conventional performance at the fundamental frequency.     

A broadband Doherty power amplifier with harmonic suppression

In this paper, the design and implementation of the broadband, Doherty power amplifier (DPA) with 2nd and 3rd harmonics suppression, with theoretical analysis is presented. In the proposed structure a novel harmonic suppressed Wilkinson power divider used in DPA, which results in harmonic suppression with high level of attenuation. Moreover the proposed DPA has major advantages in terms of the linearity and works on a wideband frequency range (2.1–2.7 GHz) with minimum 40% drain efficiency (DE). The linearity of the proposed DPA is increased extremely, which significant improvement (7 dBm) is achieved from the main amplifier. In the proposed DPA, the main and the auxiliary amplifiers are implemented using Class-AB and Class-C topology respectively with equal MRF6S27015N MOTOROLA transistors in LDMOS technology.     

Modeling, analysis and design of resonant free power distribution network for modern microprocessor systems

This paper presents design-oriented analysis of the power distribution network (PDN) for high performance microprocessor systems to realize the resonant free, close to flat output impedance magnitude over a wide frequency range. Based on the frequency domain analysis, closed form design equations and parametric curves relating the system parameters are derived. A systematic method of estimating the optimum parameters of the decoupling capacitors used in a single or multistage PDN is described to realize the output impedance of specified magnitude for the noise-free, and critically damped voltage at the microprocessor core. The design examples and simulation results are discussed to demonstrate the application of the design equations and parametric curves.     

Decoupling capacitors for multi-voltage power distribution systems

Multiple power supply voltages are often used in modern high-performance ICs, such as microprocessors, to decrease power consumption without affecting circuit speed. To maintain the impedance of a power distribution system below a specified level, multiple decoupling capacitors are placed at different levels of the power grid hierarchy. The system of decoupling capacitors used in power distribution systems with multiple power supplies is described in this paper. The noise at one power supply can propagate to the other power supply, causing power and signal integrity problems in the overall system. With the introduction of a second power supply, therefore, the interaction between the two power distribution networks should be considered. The dependence of the impedance and magnitude of the voltage transfer function on the parameters of the power distribution system is investigated. An antiresonance phenomenon is intuitively explained in this paper. It is shown that the magnitude of the voltage transfer function is strongly dependent on the parasitic inductance of the decoupling capacitors, decreasing with smaller inductance. Design techniques to cancel and shift antiresonant spikes out of range of the operating frequencies are presented. It is also shown that it is highly desirable to maintain the effective series inductance of the decoupling capacitors as low as possible to decrease the overshoots of the response of the dual-voltage power distribution system over a wide range of operating frequencies. A criterion for an overshoot-free voltage response is presented in this paper. It is noted that the frequency range of the overshoot-free voltage response can be traded off with the magnitude of the response.     

Current waveform control of PWM converter system for harmonic suppression on distribution system

The voltage waveform on the electric power distribution system is distorted by harmonic-producing loads. Regardless of the terminal voltage waveform with or without harmonics, the conventional current waveform of the pulsewidth-modulated converter systems connected to the power distribution system is always controlled to be sinusoidal. For harmonic suppression of the voltage and current on the distribution system, the authors propose the distorted current waveform whose harmonic components are in phase with the terminal voltage harmonics. The effectiveness of the proposed current waveform has been verified by experiments.     

Modeling and analysis of power distribution networks for Gigabit applications

As the operating frequency of digital systems increases and voltage swing decreases, it becomes very important to characterize and analyze power distribution networks (PDNs) accurately. This paper presents the modeling, simulation, and characterization of the PDN in a high-speed printed circuit board (PCB) designed for chip-to-chip communication at a data rate of 3.2 Gbps. The test board consists of transmitter and receiver chips wirebonded onto plastic ball grid array (PGBA) packages on a PCB. In this paper, a hybrid method has been applied for analysis, which consists of the transmission matrix method (TMM) in the frequency domain and macromodeling method in the time domain. As an initial step, power/ground planes have been modeled using TMM. Then, the macromodel of the power/ground planes has been generated at the desired ports using macromodeling. Finally, the macromodel of the planes, transmission lines, and nonlinear drivers have been simulated in standard SPICE-based circuit simulators for computing power supply noise. In addition to noise computation, the self and transfer impedances of power/ground planes have been computed and the effect of decoupling capacitors on power supply noise has been analyzed. The methods discussed have been validated using hardware measurements.     

A novel miniaturized power amplifier with nth harmonic suppression

In this paper, a novel miniaturized power amplifier (PA) matched by two proposed low pass filters (LPFs) with nth harmonics suppression is presented. In the proposed PA, the LPFs are employed as an output and input impedance transformer networks, which transform 50 Ω to the desired impedances. In the proposed PA the conventional output and input matching networks are eliminated, which results in 52% size reduction and 6% power added efficiency (PAE) improvement compared with the conventional PA. Moreover, using the LPFs at the output and input impressively suppress the unwanted harmonics (2nd–6th) with high level of attenuation. The proposed PA works at the 2.6 GHz, which is suitable for long term evolution (LTE) applications. The measured and simulated results are in the good agreement, which confirm the validity of the proposed method.     

Novel slot antennas for harmonic suppression

In this paper, novel microstrip-fed slot antennas with simple structure are proposed to achieve suppression of harmonics. To obtain this operation, conductor lines connected with ground plane in rectangular and meander type slot antennas are used, which have wide-bandstop characteristic. From the measured input impedances and radiation patterns of the proposed antennas, the second and third harmonics are effectively suppressed.     

Modeling and analysis of spacecraft power systems

A comprehensive large-scale power system modeling technique using the multiport coupling method is developed to facilitate design and analysis of present and future spacecraft power systems. The Boeing Computer Service's EASY5 program was used as the host software to meet various modeling and analysis needs for DC, small-signal, and large-signal analyses. Power subsystem or component model development from empirical data and reduced-order model generation using the complex curve-fitting technique are also introduced. A sample spacecraft power system, the simplified Direct Energy Transfer system, is modeled and its performance demonstrated     

A hybrid active filter for damping of harmonic resonance inindustrial power systems

This paper proposes a hybrid active filter for the damping of harmonic resonance in industrial power systems. The hybrid filter consists of a small-rated active filter and a 5th-tuned passive filter. The active filter is characterized by detecting the 5th-harmonic current flowing into the passive filter. It is controlled in such a way as to behave as a negative or positive resistor by adjusting a feedback gain from a negative to positive value, and vice versa. The negative resistor presented by the active filter cancels a positive resistor inherent in the passive filter, so that the hybrid filter acts as an ideal passive filter with infinite quality factor. This significantly improves damping the harmonic resonance, compared with the passive filter used alone. Moreover, the active filter acts as a positive resistor to prevent an excessive harmonic current from flowing into the passive filter. Experimental results obtained from a 20-kW laboratory model verify the viability and effectiveness of the hybrid active filter proposed in this paper     

Reliability analysis for redundancy of industrial power distribution systems

Redundancy in design of industrial power distribution system reflects the goals of service continuity and improvement of service reliability. However, this results in higher initial cost.A possible means of analyzing costs vs reliability may be reliability analysis which may offer a cost-reliability trade off decision affecting design.In this paper, a set of general equations developed at The Ralph M. Parsons Company is presented for use of computing the failure rate of a redundant system with any given number of identical units, some of which are necessary for successful operation. The remainder are redundant. From the obtained system failure rate, system reliability and system availability can be determined.     

Modeling of power electronic loads in AC distribution systems using the generalized State-space averaging method

Most of the loads in ac distribution systems have positive incremental impedance characteristic. However, power electronic loads, when tightly regulated, sink constant power from the system. Therefore, they have negative incremental impedance characteristic. This can cause negative impedance instability. Power electronic loads usually have a controlled or uncontrolled rectifier at the front end. In this paper, these loads are modeled using the generalized state-space averaging method. An assessment of their effects in ac distribution systems is also presented. Experimental results are presented to verify the proposed analysis.     

探析低压配电线路无功补偿装置谐波治理技术

本文在分析谐波污染对低压配电网影响的基础上,对低压配电线路无功补偿装置谐波治理技术进行了分析.     

Compact microstrip-fed meander slot antenna for harmonic suppression

A novel compact microstrip-fed meander slot antenna is proposed to achieve suppression of harmonics and miniaturisation of the antenna. To obtain these characteristics, a meander-type slot radiator and U-shaped conductor line connected with the ground plane are applied. The real parts of the measured input impedance at the second- and third-harmonic frequencies are nearly zero. In the measured radiation patterns in E- and H-plane, the second- and third-harmonic suppressions are observed to be approximately less than -30 dB.     

Optimum traffic distribution algorithm for multiple-satellite systems under power constraints

In satellite communications systems, in addition to frequency resources, total satellite transmitting power, (i.e., satellite power) is a crucial radio resource, due to the limited capacity of onboard electric generators. To increase system capacity, satellite power constraints have to be taken into account, as well as the frequency constraints. As one approach to this issue, we propose a traffic distribution algorithm using linear programming, which maximizes the accommodated traffic in a multiple-satellite system under satellite power constraints. The algorithms are applicable to all types of satellite systems with multiple satellites (geosynchronous Earth orbit, medium Earth orbit, low Earth orbit, or a combination of any) to increase system capacity with respect to the total amount of traffic accommodated by the systems. Finally, this paper evaluates the performance of the proposed algorithm by distributing traffic demand on the earth's surface to cells irradiated by spot-beams of a satellite and allocating frequency resources to the cells. By using the algorithm that permits power constraints, the ratio of accommodated traffic in a system was improved 12% compared with the case when no power constraints were used.