翻訳と辞書 ・ Mason Valley
・ Mason Valley (Nevada)
・ Mason Vaugh
・ Mason Verger
・ Mason Vicentino
・ Mason Walters
・ Mason Webb
・ Mason Welch Gross
・ Mason Williams
・ Mason Williams (baseball)
・ Mason Wood
・ Mason's Beach, Nova Scotia
・ Mason's gain formula
・ Mason's Hall (Richmond, Virginia)
・ Mason's Hill
・ Mason's invariant
・ Mason's Island
・ Mason's Manual of Legislative Procedure
・ Mason's mark
・ Mason's mitre
・ Mason's Root Beer
・ Mason's theorem
・ Mason, Houghton County, Michigan
・ Mason, Illinois
・ Mason, Michigan
・ Mason, Nevada
・ Mason, New Hampshire
・ Mason, Ohio
・ Mason, Oklahoma
・ Mason, Tennessee
|
|
| Mason's invariant ： ウィキペディア英語版 |
Mason's invariant
In electronics, Mason's invariant, named after Samuel Jefferson Mason, is a measure of the quality of transistors.
"When trying to solve a seemingly difficult problem, Sam said to concentrate on the easier ones first; the rest, including the hardest ones, will follow," recalled Andrew Viterbi, co-founder and former vice-president of Qualcomm. He had been a thesis advisee under Samuel Mason at MIT, and this was one lesson he especially remembered from his professor. A few years earlier, Mason had heeded his own advice when he defined a unilateral power gain for a linear two-port device, or U. After concentrating on easier problems with power gain in feedback amplifiers, a figure of merit for all three-terminal devices followed that is still used today as Mason's Invariant.
== Origin ==
In 1953, transistors were only five years old, and they were the only successful, three-terminal active device. They were beginning to be used for RF applications, and they were limited to VHF frequencies and below. Mason wanted to find a figure of merit to compare transistors, and this led him to discover that the unilateral power gain of a linear two-port device was an invariant figure of merit.〔
In his paper ''Power Gain in Feedback Amplifiers'' published in 1953, Mason stated in his introduction,
"A vacuum tube, very often represented as a simple transconductance driving a passive impedance, may lead to relatively simple amplifier designs in which the input impedance (and hence the power gain) is effectively infinite, the voltage gain is the quantity of interest, and the input circuit is isolated from the load. The transistor, however, usually cannot be characterized so easily."
He wanted to find a metric to characterize and measure the quality of transistors since up until then, no such measure existed. His discovery turned out to have applications beyond transistors.
抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』
■ウィキペディアで「Mason's invariant」の詳細全文を読む
スポンサード リンク
| 翻訳と辞書 : 翻訳のためのインターネットリソース |
Copyright(C) kotoba.ne.jp 1997-2016. All Rights Reserved.
|
|