Injection transistor-transistor logic (i.t.t.l.)

A new circuit is described that comprises a lateral-multiemitter vertical transistor structure and an inverter transistor. The circuit acts as an injection transistor-transistor logic (i.t.t.l.).     

基于MC37i模块的GSM移动通信终端的硬件设计

随着通讯技术的发展,基于GSM的移动通信终端已得到越来越广泛的应用。本文提出了基于MC37i模块的GSM移动终端设计方案,采用微控制器ATmega8L控制移动通信芯片MC37i,实现短信息的发送、接收。本设计完成了移动通信模块的启动电路、关闭电路、SIM卡电路、稳压电源电路以及控制电路的设计工作。     

Parametric upconvertor as low-noise i.f. amplifier for microwave mixers

New equations for the gain and noise performance of v.h.f. parametric upconvertors are presented and applied to the design and performance prediction of a practical upper-sideband circuit intended for application as an i.f. amplifier for microwave mixers. The measured noise figure of 0.67 (±0.1) dB at 9.5 dB gain is shown to correlate with the calculated figure, and to be close to the limiting value of around 0.5 dB at this frequency.     

USB2514i USB HUB及其应用

介绍了USB2514i的主要特性、内部结构和功能.采用USB2514i设计了一款具有1个USB上行端口、4个USB下行端口的工业级USB2.0集线器,该集线器可支持USB2.0协议的USB设备的扩展,并给出了硬件电路和PCB设计.     

Sigma-delta modulation with i.i.d. Gaussian inputs

The response of a single-loop sigma-delta modulator to an independent identically distributed (i.i.d.) Gaussian input signal is analyzed. A continuous-time stochastic model is developed and the connection of the model to the system is described. A condition is given so that the difference between the behavior of the model and that of the true system can be made arbitrarily small. Theories from renewal and Wiener processes are applied to show the convergence and mixing properties of the output sequence. Also derived is the power spectrum of the quantization noise. Compared to the spectrum when the input is DC, the i.i.d. Gaussian random process smears the discrete spectrum into band structures     

基于TC35i GSM模块的SMS设计和应用

随着通信事业的发展,基于GSM的移动终端应用已日益广泛。在研究Siemens公司生产的TC35i GSM模块的基础上,给出一种由TC35i构成的移动终端硬件电路设计和SMS编码方法,包括构成终端的数据通信电路、SI M卡电路、电源及启动电路,并探讨了在设计过程中遇到的问题和解决的方法。该设计可以完成短消息的收发,与PC机进行数据传输等功能。已成功应用在基于GPS和GSM网络的新型汽车防盗系统中。     

V-groove-isolated i.i.l. circuits

A new method using V-grooves for dielectric isolation of i.i.l. circuits is described. Basic devices and circuits have been realised and tested. The process results in a simplified, low-temperature isolation step and yields an increased packing density.     

Identification of fifth-order Volterra systems using i.i.d. inputs

In this study, we show that the minimum mean square estimate (MMSE) of the parameters of a fifth-order Volterra model can be obtained in closed-form when the input is independent and identically distributed (i.i.d). The derived closed-form expressions of the kernel coefficients can be used for identifying Volterra systems with arbitrary memory. Some simulation results are presented to illustrate the proposed identification method.     

A coplanar X-band AlGaN/GaN power amplifier MMIC on s.i. SiC substrate

This work presents a two-stage high-power amplifier monolithic microwave integrated circuit (MMIC) operating between 9 GHz and 11 GHz based on a fully integrated AlGaN/GaN high electron mobility transistor (HEMT) technology on s.i. SiC substrate and is suitable for radar applications. The MMIC device with a chip size of 4.5/spl times/3 mm/sup 2/ yields a linear gain of 20 dB and a maximum pulsed saturated output power of 13.4 W at 10 GHz equivalent to 3.3 W/mm at V/sub DS/=35V, 10% duty cycle, and a gain compression level of 5 dB. Further, dc reliability data are given for the MMIC HEMT technology.     

The Characteristics of a Hydrogenated Amorphous Silicon Semitransparent Solar Cell When Applying n/i Buffer Layers

In this work, buffer layers with various conditions are inserted at an n/i interface in hydrogenated amorphous silicon semitransparent solar cells. It is observed that the performance of a solar cell strongly depends on the arrangement and thickness of the buffer layer. When arranging buffer layers with various bandgaps in ascending order from the intrinsic layer to the n layer, a relatively high open circuit voltage and short circuit current are observed. In addition, the fill factors are improved, owing to an enhanced shunt resistance under every instance of the introduced n/i buffer layers. Among the various conditions during the arrangement of the buffer layers, a reverse V shape of the energy bandgap is found to be the most effective for high efficiency, which also exhibits intermediate transmittance among all samples. This is an inspiring result, enabling an independent control of the conversion efficiency and transmittance.     

Subthreshold behaviour of e.s.f.i.-s.o.s. transistors

Theoretical and experimental results are presented which illustrate the influence of various parameters on the subthreshold behaviour of e.s.f.i.-s.o.s. transistors. The numerical analysis accounts for the thin silicon film and the existence of a second interface. A comparison is made with a corresponding bulk transistor, furthermore, between a two- and a one-dimensional analysis of e.s.f.i.-s.o.s. m.o.s.t. The agreement for real cases is found to be excellent.     

Improvements for general-purpose s.s.i. logic packages and m.s.i./l.s.i. logic subsystems

Various specifications for general-purpose logic packages for random-logic design use have been previously proposed. Current research interests in more powerful logic design techniques, however, are suggesting newer s.s.i. integrated-circuit packages for future use, and newer and more compact subsystems within future m.s.i./l.s.i. logic packages.     

A study of the i/p interface for flexible n–i–p a-Si:H thin film solar cells

In this paper, the influence of i/p interface buffer layer on the performance of flexible n–i–p a-Si:H thin film solar cells is studied. The results show that the dopant distribution in the buffer layer has large effect on the property of solar cells. A larger open circuit voltage and fill factor can be obtained when methane is introduced into the chamber prior to diborane during the deposition of buffer layer. The AMPS simulation indicates that it is beneficial to improve the built-in electric field in the i layer when the carbon is doped prior to boron, thus the carrier transport properties are improved. By further optimizing the deposition parameter, an initial conversion efficiency of 5.668% is achieved for the a-Si:H thin film solar cells on the PI substrates at 150 °C.     

Propagation delay time of i.i.l. at low current levels

It is shown that the propagation delay time of i.i.l. at low current levels is given by tr/2 if tf < tr, where tf is the fall time and tr the rise time at an i.i.l. input node. An expression for tr and tf can easily be found.     

Binary baseband polar signals in combination with continuous and impulsive noise with i.s.i.

This letter presents the performance of a binary baseband polar system in the presence of a mixture of continuous and impulsive noise and intersymbol interference (i.s.i.). The results obtained are very general and the system performance in special cases like purely continuous noise or purely impulsive noise with or without i.s.i. can be easily derived from the general results.     

Wide-range electronic tuning of a Gunn diode by an yttrium-iron garnet (y.i.g.) ferrimagnetic resonator

A Gunn diode was mounted in a coaxial line circuit and tuned by a y.i.g. spherical single-crystal resonator. The oscillator could be tuned over the range 5.8?10.8 GHz and, over nearly all of this range, the frequency varied linearly with magnet-coil current. Although successful tuning has been achieved, many aspects of design remain to be studied.     

On the MDL principle for i.i.d. sources with large alphabets

Average case universal compression of independent and identically distributed (i.i.d.) sources is investigated, where the source alphabet is large, and may be sublinear in size or even larger than the compressed data sequence length n. In particular, the well-known results, including Rissanen's strongest sense lower bound, for fixed-size alphabets are extended to the case where the alphabet size k is allowed to grow with n. It is shown that as long as k=o(n), instead of the coding cost in the fixed-size alphabet case of 0.5logn extra code bits for each one of the k-1 unknown probability parameters, the cost is now 0.5log(n/k) code bits for each unknown parameter. This result is shown to be the lower bound in the minimax and maximin senses, as well as for almost every source in the class. Achievability of this bound is demonstrated with two-part codes based on quantization of the maximum-likelihood (ML) probability parameters, as well as by using the well-known Krichevsky-Trofimov (KT) low-complexity sequential probability estimates. For very large alphabets, kGtn, it is shown that an average minimax and maximin bound on the redundancy is essentially (to first order) log(k/n) bits per symbol. This bound is shown to be achievable both with two-part codes and with a sequential modification of the KT estimates. For k=Theta(n), the redundancy is Theta(1) bits per symbol. Finally, sequential codes are designed for coding sequences in which only m相似文献   

Speaking of infinity [i.i.d. strings]

We study the redundancy of three approaches to compression of independent and identically distributed (i.i.d.) strings over large, possibly infinite, alphabets: standard compression of the string itself and compression of the string's shape and pattern, which describe its symbols' relative magnitude and precedence, respectively. We determine the rate at which per-symbol standard redundancy increases to infinity as the alphabet size increases, show that the maximum per-symbol shape redundancy is between 0.027 and 1, and compare these to results showing that per-symbol pattern redundancy diminishes to zero for all alphabet sizes. We relate these concepts to ordered and unordered partitions of integers and sets, and use this framework to explore relations between several combinatorial quantities, including the Bell, Fubini, and second-type Stirling numbers.     

Quadratic system identification using higher order spectra ofi.i.d. signals

The properties of higher order moment sequences and higher order spectral moments of an i.i.d. (independent, identically distributed) process up to fourth-order are discussed. These properties are utilized to develop algorithms to identify time-invariant nonlinear systems, which can be represented by second-order Volterra series and which are subjected to an i.i.d. input. A relatively simple solution for estimating the linear and quadratic transfer functions, which requires neither the calculation of the higher order spectral moments of the input for various frequencies nor the calculation of the inverse of matrix, is shown to exist, even though the second-order Volterra series is not an orthogonal model for an i.i.d. input (unless the input is a white Gaussian process)     

Transmission-mode y.i.g. dispersive filter for wide-band pulse compression

It has recently been reported that yttrium-iron-garnet microwave variable-delay lines can be operated in a transmission mode of operation rather than in the usual reflection mode of operation by optical-contact bonding quarterwave plates to both ends of the y.i.g. rod.1.2 This is a distinct advantage for many delay-line applications, because the undelayed direct feedthrough can be suppressed to a much higher degree when input and output lines are at opposite ends of the y.i.g. rod, which is mounted in a tightly fitting hole in a brass block. One of the most promising applications of the y.i.g. delay line is in wide-band microwave pulse-compression filters. The successful operation of a y.i.g. delay line, to obtain compressed signals in a transmission with large suppression of direct leakage of undelayed signals, is reported.