摘要:

By comparing the travelling-wave gyrotron with the conventional travelling-wave tube, it is shown that the gyrotron interaction mechanism can be described using Pierce-type parameters. These parameters are subsequently employed to highlight some gain and frequency characteristics of the travelling-wave gyrotron, attention being focused particularly on harmonic operation.

DOI:10.1049/ip-i-1.1980.0009

出版商:IEE    

年代:1980

数据来源: IET

摘要:

A study of the many methods used for measuring base spreading resistance,rbb' has shown that some of them are inaccurate or unfeasible when applied to planar transistors. Methods investigated cover the d.c.to microwave frequency range and include coherent and incoherent signal measurements. Comparisons are also made of measured and theoretical values for several types of device. The thermal-noise method appears best because of its accuaracy and wide applicability.

DOI:10.1049/ip-i-1.1980.0010

出版商:IEE    

年代:1980

数据来源: IET

摘要:

This paper presents an analytical model for depletion-mode m.o.s. transistors which is particularly suitable for c.a.d. applications, and improves the current state of the art by including the effect of the surface-mobility degradation induced by the transverse field. The model is used to fit experimental data obtained on long-channel devices, and turns out to give good results; the mean square error over the wholeID/VDSplane, for several values of the gate- and bulk-source voltages, is of the order of 1%

DOI:10.1049/ip-i-1.1980.0011

出版商:IEE    

年代:1980

数据来源: IET

摘要:

The punch-through diode is a bidirectional nonlinear device whose speed of response makes it suitable for the suppression of very fast transients. It is autoprotecting above a minimum current density. A simple model to estimate the influence of design parameters on thermal properties is presented, and discrepancies in existing criteria for maximum power-handling capability are discussed.

DOI:10.1049/ip-i-1.1980.0012

出版商:IEE    

年代:1980

数据来源: IET

摘要:

The transistor transit-time oscillator (t.t.t.) feasibility has been demonstrated in recent years. Small signal, negative resistance and oscillations were obtained and the main limitations were reported. The present paper gives device potential performances under large-signal c.w. operations and proposes an optimised structure for 10 GHz.

DOI:10.1049/ip-i-1.1980.0013

出版商:IEE    

年代:1980

数据来源: IET

摘要:

Design rules for uniformly doped Baritt diodes in the frequency range 8 to 40 GHz are derived. The fabrication of Ka-band Baritt diodes which deliver up to 1.7 mW is described. The theoretical and experimental results of the investigated diodes fit very well.

DOI:10.1049/ip-i-1.1980.0014

出版商:IEE    

年代:1980

数据来源: IET

摘要:

Techniques for evaluating the surface potential and the effective surface mobility of a m.o.s. transistor are described. These techniques include determination of the fixed oxide charge density, the surface-state charge density and the average donor concentration. The surface potential is evaluated as a function of gate voltage, because this dependence is necessary in order to calculate the density of surface states from charge-pumping measurements. The effective surface mobility is evaluated as a function of bias, because this dependence is necessary in order to develop a bias-dependent 1/fnoise model of a m.o.s. transistor.

DOI:10.1049/ip-i-1.1980.0015

出版商:IEE    

年代:1980

数据来源: IET

摘要:

A 1/fnoise model of an m.o.s. transistor is developed which verifies previously observed dependences on the geometry and the density of surface states, but in addition predicts an explicit bias dependence. This model predicts that input 1/fvoltage noise gradually increases as the gate voltage increases near threshold and continues to increase for gate voltages well above threshold. It also predicts a gradual decrease in noise as the drain voltage increases to saturation. These prediction are experimentally verified.

DOI:10.1049/ip-i-1.1980.0016

出版商:IEE    

年代:1980

数据来源: IET

摘要:

The far-field, near-field and waist-intensity distributions are investigated in the nonlinear flux-current regime (kink) of a stripe-geometry d.h. laser at each of its two facets. The results are interpreted as a displacement of a deformable light guide or filament within the laser stripe, which acts as an additional built-in antiguide. Asymmetries in the far-field side-lobe intensities indicate enhanced refraction losses of the displaced filament towards that antiguide boundary towards which the near field moves and the far-field main lobe turns.

DOI:10.1049/ip-i-1.1980.0017

出版商:IEE    

年代:1980

数据来源: IET

摘要:

This research note reports an improved circuit for GaAs diode/f.e.t. logic that is particularly suited for high-speed-frequency-divider applications. It is also demonstrated that there is a substantial power-reduction advantage in diode/f.e.t. logic over buffered-f.e.t. logic, even on single uniformly doped GaAs active layers. Comparisons have been made on these two logic approaches on i.c.s using nominally two-micrometre-gate-length f.e.t.s.. Propagation delays of 200 to 300 ps at 3 to 4 mW power consumption have been measured on diode/f.e.t. logic gates. Similar propagation delays are observed on buffered-f.e.t. logic, but at up to six times the bias power.

DOI:10.1049/ip-i-1.1980.0018

出版商:IEE    

年代:1980

数据来源: IET