摘要:

Frequently it is desirable to know the statistical properties of the output of certain frequency sensitive devices when some type of random signal is impressed. Since most devices of this type are followed by low pass filters, this problem is one of determining the statistics of a filtered signal.The problem of finding the probability density of the difference of two dependent random variables has not been solved in any general way. Also, the problem of finding the statistical properties of the output of a linear filter upon which a non‐Gaussian random signal is impressed has been considered by only a very few writers.The first sections of this paper gives a solution of the case of a frequency discriminator with no low pass filter, excited by a narrow band spectrum, and is solved by expressing the output of the device as the difference of two independent random quantities, which allows the use of the characteristic function method.The later sections contain a solution of the problem when a low pass filter is present at the discriminator output. This is done by obtaining the predominant moments of the density from a series expansion which gives a good approximation to the nature of that density Also, in this regard, the approach of the density to a Gaussian one, as the output filter band is made very narrow, is clearly shown.

ISSN:0021-8979    

DOI:10.1063/1.1721836

出版商:AIP    

年代:1954

数据来源: AIP

摘要:

An attempt has been made to derive, in terms of valve geometry, theoretical expressions for the constants of an elliptic triode, the shape of the electrodes of which belongs to a family of confocal ellipses. The amplification factor (&mgr;) is derived by following the method of conformal transformation. Result shows that in general it varies with the parametric angle &thgr; of the ellipse—decreasing from the direction of minor to that of the major axis. The average value of &mgr; increases with increasing value of the eccentricity of the grid and with decreasing value of the eccentricity of the anode. Curves for ready evaluation of &mgr; for any value of &thgr; are given. The problem of design of an elliptic triode having a constant &mgr; for all values of &thgr; is also considered and its method of solution indicated. An expression for the perveance (P) has also been obtained by adopting the procedure followed by O'Neill for determining the perveance of a plane diode having filamentary cathode. The expression shows that the value of perveance is determined mainly by the eccentricity of the grid and the focal distance.To illustrate the practical applications of the various deductions made, a numerical example, involving the design of a 6C5‐GT/G type triode, is given.

ISSN:0021-8979    

DOI:10.1063/1.1721837

出版商:AIP    

年代:1954

数据来源: AIP

ISSN:0021-8979    

DOI:10.1063/1.1721838

出版商:AIP    

年代:1954

数据来源: AIP

ISSN:0021-8979    

DOI:10.1063/1.1721839

出版商:AIP    

年代:1954

数据来源: AIP

ISSN:0021-8979    

DOI:10.1063/1.1721840

出版商:AIP    

年代:1954

数据来源: AIP

ISSN:0021-8979    

DOI:10.1063/1.1721842

出版商:AIP    

年代:1954

数据来源: AIP