Electrochemical supercapacitors are rechargeable electrochemical energy storage devices similar to batteries, but with different performance characteristics. Supercapacitors can store more power in a smaller volume and often at a lower cost. In contrast to batteries, supercapacitors have incredibly long cycle life (> 1000,000 cycles), and could be charged in less than a second. Their unique characteristics allow them to complement batteries in applications where high power and low weight are essential, including directed-energy weapons, compact pulsed power, mobile power quality devices, and peak power sources for aircraft and electric vehicles. In our project we focus on materials for high energy / high power supercapacitors.

关键词：电子信息；电子；功率；电容器

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Experimental results on 60GHz band signal transmission through ECOR (Electromagnetic Coupling of Open-Ring Resonators) are shown. Through sapphire substrate, 60-70GHz band signal are transmitted with 58.9transmission efficiency and 7.4GHz bandwidth. However, the transmission band was shifted about 10GHz higher frequency. The reason is under investigation. ECOR technology is extended to lower frequencies for non-contact power transmission. The technology will benefit to power connectors for equipment modules where the problems caused by humidity and mechanical failure will be eliminated. A new diode structure for RF signal rectification, loss mechanism in rectenna circuits and the effect of wetting to ECOR transmission will be presented.

关键词：电子信息；电子；电磁耦合；环谐振器

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The radio frequency (RF) power amplifier (PA) is one of the most critical components in designing transmitters in wireless communication systems, and its efficiency dominates the overall efficiency of the transmitter. On one hand, the PA is most power consuming ; for example, in a cellular phone, the battery life is largely determined by the power efficiency of the PA. On the other hand, it is desirable to have the ability to transmit data at the highest possible rate for a given channel bandwidth, i.e., to have high spectral efficiency [1].

关键词：电子信息；电子；功率放大器；线性化技术

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This program focused on new materials and fiber designs towards the realization of 100+ kW class eye-safe fiber lasers based on the following guiding principles: large mode area, single mode, purity of polarization state, minimization of nonlinear effects, compatibility with all-fiber pumps, and high temperature buffer coatings. Over the duration of this program the most significant findings are discussed below in the following sections: (1) Gain guided index anti guided fiber lasers; (2) High temperature fiber coatings; (3) Tm doped fiber lasers 4. Tm doped Photonic Crystal Fiber (PCF) lasers.

关键词：电子信息；电子；高功率；激光器

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Forced flow of fluids undergoing phase change in traditional single- phase cold plates is an effective way to manage waste heat removal of vehicle power electronics. Such cold plates come in a variety of standard styles, ranging from circular-tubed cold plates and flat-tube cold plates, to more exotic designs such as louvered and offset fin cold plates. The mechanisms of heat transfer in a two-phase system are different than single-phase, and as such, improvement can be made by custom designing cold plates for two-phase operation. Past research has focused on surface modifications that enhance nucleate boiling, convective vaporization, or both during two-phase operation. The method that has gained the most attention is the use of inner grooved tubes for performance improvement in refrigeration applications. Despite the popularity of inner grooved tubes, the flow mechanisms that deliver performance enhancement are not fully understood. The absence of phenomenological insights and physical models makes it difficult to transition inner grooved tube technology from conventional refrigeration equipment to cold plates. Therefore, understanding the physical mechanisms underpinning two-phase performance enhancement in inner grooved tubes is at the heart of this report.

关键词：电子信息；电子；冷却板；电力产品

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This program has successfully accomplished its main objective in that large core single-mode Ge-doped and Yb-doped CCC fibers have been developed as a platform for monolithically-integrated building blocks (individual laser channels) of high power beam-combined fiber laser arrays. Robust single-mode performance of CCC fibers with core sizes of up to approximately 60m has been rigorously demonstrated. Various CCC fiber based high power lasers have been also demonstrated, including 600W SBS-free single-frequency linearly-polarized cw fiber MOPA system, mJ pulsed and high-pwer ultrashort-pulse CPA systems. Accurate numerical modeling tools for designing CCC structures have been developed. Fabrication of CCC fibers reached such a degree of maturity that they have become available commercially. Furthermore, this program resulted in a successful demonstration of SBS suppression in acoustic-guidance tailored fibers with up to 13dB SBS threshold increase, which to our knowledge constitutes one of the largest SBS suppression achieved to date. UUIC group also performed an extensive study of SBS gain coefficient magnitude and spectrum in a variety of fiber glass materials.

关键词：电子信息；电子；激光器；纤维技术

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This work was done in the following directions: 1. Excitation of parasitic waves near cutoff in forward-wave amplifiers; 2. Periodic dielectric slow-wave structures; 3. Role of metallic dust on operation of high-power sources of electromagnetic radiation. The problem of excitation of dangerous parasitic modes in high-power amplifiers operating in high-order waves was studied, first, assuming strong focusing fields, in which electrons perform 1D motion. Then, the approach was generalized to the case of weak guiding fields, in which electrons exhibit 3D motion. The effect of guiding fields and other parameters on the conditions of parasitic excitation was analyzed and illustrated by design examples. Periodic dielectric slow-wave structures may exhibit an interesting class of new metamaterials attractive for high-power, millimeter-wave amplifiers. The theory of such structures has been developed and illustrated by some examples. Heating and melting of small micro-particles (metallic dust) in strong microwave fields may initiate the breakdown events in high-power microwave (HPM) sources. These processes have been studied in HPM sources operating in rep-rate regimes.

关键词：电子信息；电子；功率放大器；短波

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The design of power amplifiers in any semi-conductor process is not a trivia exercise and it is often encountered that the simulated solution is qualitatively different than the results obtained. Phenomena such as oscillation occurring either in-band or out of band and sometimes at subharmonic intervals, continuous spectrum noticed in some frequency bands, often referred to as chaos, and jumps and hysteresis effects can all be encountered and render a design useless. All of these problems might have been identified through a more rigorous approach to stability analysis. Designing for stability is probably the one area of amplifier design that receives the least amount of attention but incurs the most catastrophic of effects if it is not performed properly. Other parameters such as gain, power output, frequency response and even matching may suitable mitigation paths. But the lack of stability in an amplifier has no mitigating path. In addition to of loss of the design completely there are the increased production cycle costs, costs involved with investigating and resolving the problem and the costs involved with schedule slips or delays resulting from it. The Linville or Rollett stability criteria that many microwave engineers follow and rely exclusively on is not sufficient by itself to ensure a stable and robust design. It will be shown that the universal belief that unconditional stability is obtained through an analysis of the scattering matrix S to determine if 1 and (Delta)(sub S) < 1 is only part of the procedure and other tools must be used to validate the criteria. The research shown contributes to the state of the art by developing a more thorough stability design technique for designing amplifiers of any class, whether that be current mode or switch mode, than is currently undertaken with the goal of obtaining first pass design success.

关键词：电子信息；电子；功率放大器；集成

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A broadband power amplifier design approach was used to design several monolithic microwave integrated circuits (MMICs) using a 0.13- m gallium arsenide (GaAs) pseudomorphic high electron mobility transistor (PHEMT) process from TriQuint Semiconductor. The design and fabrication of these circuits were performed as part of the fall 2011 Johns Hopkins University (JHU) MMIC Design Course, taught by the author. The design approach is taught by Dale Dawson in the JHU Power MMIC Design Course. This approach is useful for designing relatively broadband amplifiers that are limited only be the active transistor's 'Q'.

关键词：电子信息；电子；集成电路；放大器

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A brief review of the properties of the material and device structures for photodiodes, and an update on the performance of high power waveguide photodiodes, including simulation results of directional coupled waveguide photodiodes, for analog link applications will be provided. The underlying physical mechanisms responsible for nonlinearities in high power photodiodes will be discussed in the presentation.

关键词：电子信息；电子；高功率；光电二极管

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