Conventional Mode Of Operation Research Articles

A New Process for the Evaluation of Upper Winds

The present system of evaluating upper winds by means of radar/radio tracking of pilot and radiosonde balloons is in its most general form to be considered as an overdetermined observation system. The redundancy of information in such systems may be used to improve the overall precision of measurement by applying the well-known theory of adjustment of observations. In this paper a scheme for computation is presented, not only for the case of a flat earth, but also for the case including the effect of the earth's curvature. The scheme is particularly feasible for implementation in practice by means of electronic data processing. The proposed scheme has the advantage that the numerical process also incorporates the conventional modes of operation. Apart from an adjustment procedure a simple smoothing process is described which depends on the accuracy attainable by the measuring technique. This effectuates a partial separation of the instrumental errors from real wind fluctuations. Some numerical data give an impression of the gain in accuracy and the effect of a certain amount of smoothing.

UHF Backward-Wave Parametric Amplifier

This paper describes a breadboard model of a UHF varactor diode backward-wave parametric amplifier that can be electronically tuned over an octave tuning range (250-500 Mc). It operates in a mode that has a relatively constant idler frequency; however, it uses two forward-wave transmission lines in contrast to the backward-wave transmission line requirement previously reported. A theoretical discussion on the design considerations of this mode is presented and applied to the UHF model. Measurements taken in the conventional mode of operation (output frequency equal to the input frequency) yielded voltage gain bandwidth products in excess of 100 Mc and over-all effective receiver noise temperatures of less than 140/spl deg/k. Detailed measurements in the mode where the constant idler frequency is used as the output were not taken because directional filters and circulators, which are necessary in this mode, were not available.

Pulse-Width Control of Transistors

Duty cycle, or pulse width, modulation can be used to advantage in transistor circuits where the desired output is a direct current or slowly varying voltage such as required in proportional control systems. For a prescribed transistor dissipation, several times greater load power can be controlled by this technique than with class A operation. Conversely, for a given load power, the transistor can be operated at lower dissipation and thus at higher temperatures than is permissible with conventional modes of operation. Circuits have been devised for several different types of load circuits and also for signal generation. Combination of the duty-cycle modulation generation and output circuits yields a unique direct current amplifier.