SHARE
TWEET

Untitled

a guest Apr 25th, 2011 237 Never
  1. >> help db
  2.  DB Convert to decibels.
  3.     DB(X) converts the elements of X to decibel units
  4.     across a 1 Ohm load.  The elements of X are assumed
  5.     to represent voltage measurements.
  6.  
  7.     DB(X,U) indicates the units of the elements in X,
  8.     and may be 'power', 'voltage' or any portion of
  9.     either unit string.  If omitted, U='voltage'.
  10.  
  11.     DB(X,R) indicates a measurement reference load of
  12.     R Ohms.  If omitted, R=1 Ohm.  Note that R is only
  13.     needed for the conversion of voltage measurements,
  14.     and is ignored if U is 'power'.
  15.  
  16.     DB(X,U,R) specifies both a unit string and a
  17.     reference load.
  18.  
  19.     EXAMPLES:
  20.        
  21.     % Example 1:Convert 0.1 volt to dB (1 Ohm ref.)
  22.                 db(.1)           % -20 dB
  23.  
  24.     % Example 2:Convert sqrt(.5)=0.7071 volts to dB (50 Ohm ref.)
  25.                 db(sqrt(.5),50)  % -20 dB
  26.  
  27.     % Example 3:Convert 1 mW to dB
  28.                 db(1e-3,'power') % -30 dB
  29.  
  30.     See also abs, angle.
RAW Paste Data
Top