DOI:10.1049/ree.1973.0054

出版商:IERE    

年代:1973

数据来源: IET

摘要:

In this paper a method of generating a circle test pattern for television is described. An important feature of the method is the use of switching matrices as the source of line information. Corresponding generator organization is given and the generated test pattern is shown.

DOI:10.1049/ree.1973.0055

出版商:IERE    

年代:1973

数据来源: IET

摘要:

General purpose correlators are too expensive for flow metering applications and do not give a velocity measurement directly. Two methods of simplification can be used, quantization and what the authors have termed the two-point difference method. Some of the implications and advantages of these techniques are discussed.

DOI:10.1049/ree.1973.0056

出版商:IERE    

年代:1973

数据来源: IET

摘要:

A new structure is discussed for a frequency response analyser incorporating a four-path filter to execute the correlation process. A detailed analysis of the filter is presented. The instrument covers the frequency range 10 Hz >f< 100 kHz and its advantages include higher frequency operation and increased dynamic range compared with previous designs and a voltage programmable sweep capability over a frequency range in excess of 1000 : 1.

DOI:10.1049/ree.1973.0057

出版商:IERE    

年代:1973

数据来源: IET

摘要:

The paper utilizes the phase variable form of the state equation describing a given linear network. The networks that are considered are those most commonly used, namely, phase advance/phase retard and notch networks, to stabilize a servo system. Practical results are given which illustrate the simplicity of tuning the characteristics and which demonstrate that implementation of these filters is a significant improvement in the 'state of the art'.

DOI:10.1049/ree.1973.0058

出版商:IERE    

年代:1973

数据来源: IET

摘要:

Experimental results and theoretical estimates for the excitation efficiency of the PE20 and PMU dielectricloaded trough waveguide modes by the LSE10 and LSMn dielectric-loaded rectangular waveguide modes respectively are presented. The high efficiencies predicted are generally in good agreement with the experimental results.

DOI:10.1049/ree.1973.0059

出版商:IERE    

年代:1973

数据来源: IET

摘要:

A model for the velocity-field characteristic of gallium arsenide is developed which is based on the assignment of two separate temperature values to the carrier populations of upper and lower conduction-band valleys. The model takes into account two significant factors; (1) the temperature dependence of carrier relaxation time, and (2), the effect of high electric field intensities on the mobility of carriers in the upper conduction-band valley. The resulting characteristic agrees well with those both predicted and observed by other workers whilst the model allows direct insertion of material parameters into the relevant equations. As the ambient temperature increases, a significant reduction in the ratio of peak-to-valley carrier velocity is shown to occur, together with a small increase in the value of the threshold field.

DOI:10.1049/ree.1973.0060

出版商:IERE    

年代:1973

数据来源: IET

DOI:10.1049/ree.1973.0062

出版商:IERE    

年代:1973

数据来源: IET