摘要:

A new configuration of the travelling-wave microwave to DC convertor using distributed DC retardation has been investigated, and has been found to overcome the disadvantages of the conventional configuration. A high efficiency, not critically dependent on the power level, appears attainable.

DOI:10.1049/ip-i-1.1985.0001

出版商:IEE    

年代:1985

数据来源: IET

摘要:

The effect of dust on the performance of photovoltaic concentrators has been investigated. The dust concentration in the air was measured continuously during the test period, and the rate of dust accumulation on the concentrator's surface was determined. For the purpose of comparison, an identical concentrator, the surface of which was kept clean, was evaluated simultaneously with the dusty concentrator. The change of theI/Vcharacteristics as a result of dust accumulation was related to the amount of dust accumulated per unit area of the collector surface (g/m2). It has been shown that the major reductions in the short-circuit current, cell temperature and the efficiency occur as the dust starts to deposit onto the collector surface, but the rate of decrease is slower for dust accumulations beyond 2 g/m2. It is argued that the dust accumulation per unit area is a more representative parameter than the exposure time for such studies.

DOI:10.1049/ip-i-1.1985.0002

出版商:IEE    

年代:1985

数据来源: IET

摘要:

The applicability of a novel scheme—Joule displacement microscopy—to the characterisation of electromigration is demonstrated. It involves the detection of local changes to electric resistivity. The relative influence of four parameters which govern the electromigration process-current density, temperature, and their spatial divergences, are examined. It is shown that it is thereby possible to understand the differences in the impact of electromigration observed in films of aluminium and gold.

DOI:10.1049/ip-i-1.1985.0003

出版商:IEE    

年代:1985

数据来源: IET

摘要:

TheI/Vcharacteristics of ann-channel silicon-gate folded MOS transistor, having a large value of gate width/length ratio, has been investigated. Significant deformations of these characteristics are reported and an explanation of the observed inconsistency with typical transistor models is proposed.

DOI:10.1049/ip-i-1.1985.0004

出版商:IEE    

年代:1985

数据来源: IET

摘要:

The limitation of the maximum current gain attainable in a silicon bipolar transistor is due to many factors whose main effect is to prevent the blocking of minority carrier injection in the emitter. In the paper we show that blocking of minority carrier injection in the emitter, and hence a large increase of the current gain, can be achieved with a new type ofnpnbipolar transistor, where the emitter is made ofn-doped hydrogenated amorphous silicon (a-Si: H). It is demonstrated that the very low mobility of carriers and the large bandgap (around 1.8 eV) in amorphous silicon are the two main factors involved in the improvement of the gain. The feasability and the potential interest of the device are studied in detail on the basis of the up-to-date known electrical properties of doped a-Si: H.

DOI:10.1049/ip-i-1.1985.0005

出版商:IEE    

年代:1985

数据来源: IET

摘要:

One of the serious problems which must be overcome in realising a 1 Mbit DRAM is high-power dissipation associated with data-line charging and discharging. To solve this problem, this paper proposes the following three techniques, which permit power reduction by about one-quarter: a multidivided data-line structure, 512 refresh cycles and an on-chip voltage limiter circuit. These techniques are proven to be useful through the design and evaluation of an experimentaln-MOS 1 Mbit DRAM with a 46 mm2chip size. The chip fabricated provides a 295 mW operating power at a 260 ns cycle time despite the fast access time of 90 ns. The possibility of further power reduction is also described.

DOI:10.1049/ip-i-1.1985.0006

出版商:IEE    

年代:1985

数据来源: IET

摘要:

A laser model for narrow-striped DH lasers, in which there is good carrier confinement as well as good optical confinement, is proposed and analysed. Such conditions are encountered in the buried-heterostructure laser, the stripe buried-heterostructure laser, and the buried-optical-waveguide-structure laser. It is found that the model is stable, showing no self-sustained oscillations, when the value of the factorhis greater than 350. The factorh= (2πLe/W)2, whereLeis the effective diffusion length of carriers in the active layer andWis the stripe width. A device is proposed, which will generate high-speed optical pulses in a predictable and reproducible manner.

DOI:10.1049/ip-i-1.1985.0007

出版商:IEE    

年代:1985

数据来源: IET

摘要:

A 32 bit, two/single phase CCD has been fabricated on GaAs using a simple four-stage fabrication process. Its operation is described at frequencies of up to 560 MHz. The charge transfer efficiency was estimated to be in excess of 0.998 per transfer below 100 MHz.

DOI:10.1049/ip-i-1.1985.0008

出版商:IEE    

年代:1985

数据来源: IET

摘要:

A Monte-Carlo simulation program has been developed to simulate the motion of electrons in a submicron GaAs diode with an AlxGa1−xAs/GaAs heterojunction cathode. The electric field in the diode is self-consistently determined by solving Poisson's equation under reasonable boundary conditions. The distributions of electron energies and electron velocities, and the profiles of the electron density, electric field and average electron velocity, are computed. Based on these data, various properties of the electron transport in a submicron diode with a hot-electron injection mechanism are discussed.

DOI:10.1049/ip-i-1.1985.0009

出版商:IEE    

年代:1985

数据来源: IET

摘要:

In this paper dealing with the so-called quasisaturation current limitation in high-voltage VDMOS transistors, the authors have given a linear law on the dependence of the on-state conductance on the square-root of the drain bias. A four-section model, taking into account the pinching of the drain epilayer by the space-charge extensions and the current spreading in the bulk, accounts for the quasisaturation phenomenon, and the linear behaviour of the empirical law is well verified. Finally, the scaling-up effects on the high-voltage-device current capability are discussed.

DOI:10.1049/ip-i-1.1985.0010

出版商:IEE    

年代:1985

数据来源: IET