1,721,166 research outputs found
An HBT unilateral model to design distributed amplifiers
No full textA novel heterojunction bipolar transistor (HBT) unilateral model oriented to a fast prediction of the performance of HBT monolithic-microwave integrated-circuit distributed amplifiers is proposed. The HBT unilateral model includes, by simple expressions, the effects caused by the HBT parasitics. A graphical design procedure for HBT distributed amplifiers is also proposed. This method is based on a set of generalized charts and represents a simple and fast design tool for designers. Comparisons between the performance of specially designed HBT distributed amplifiers and the results obtained using the HBT unilateral model demonstrate the validity of the proposed approach
On the influence of electron-beam parameters on TWT small-signal gain
No full textThe electron beam is one of the main components in traveling-wave tubes (TWTs). A study on the influence of the parameters related to the electron beam on small-signal gain of TWTs is proposed. In particular, the effect of the variations of electron-beam voltage, the perveance of the electron gun, and electron beam radius are investigated. A five-section TWT was considered in the study. (C) 2002 Wiley Periodicals, Inc
AN APPROACH TO DISTRIBUTED-AMPLIFIER BASED ON A DESIGN-ORIENTED FET MODEL
No full textA Design-Oriented FET model in conjunction with an appropriate design procedure for distributed amplifiers is presented. The advantage of including the effects caused by FET parasitics in a newly defined simple unilateral FET circuit to be utilized in the conventional distributed amplifier design procedure allows an accurate prediction of the low-frequency gain and the 3-dB cutoff frequency, The simplicity of this formulation and a set of generalized design charts provide an interesting opportunity to designers. Comparisons among different experimental data from literature and the results obtained by this theory confirm the validity of the Design-Oriented FET model and the effectiveness of the given graphical design method
A study on helix pitch tolerance impact on TWT small-signal gain
No full textTraveling-wave tubes (TWTs) consist of several sections with different helix pitch to provide the required small-sigqal gain. An extensive study aiming to improve the comprehension of the effect of the helix pitch manufacturing tolerances on the TWT small-signal gain has been completed. The obtained results demonstrate the relevant impact on the TWT small-signal gain when the helix pitch deviates from its nominal value and allow devising a tuning procedure for the realized tubes
Improvement as a Criterion for the anti-seismic Safeguarding and Structural Conservation of Historical Sites: Methodology and Examples
No full textRegional Centre of Competence foe the conservation, enhancement and accessibility of cultural and environmental resources, designed and financed by the Regione and Universities of Campania (Italy)
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Improvement as a Criterion for the anti-seismic Safeguarding and Structural Conservation of Historical Sites: Methodology and Examples
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