Antenna: volts and amps

[last updated: 2024-02-15]
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This page is rough and in development...
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• The electrical behavior/performance between a radio and antenna system can be fully described by:
  • power (watts) sent into the antenna
  • frequency (MHz) of the transmitted signal
  • impedance (ohms) of feedline
  • impedance (ohms) of the antenna

  All the other quantities that we use to describe things can be calculated from these primary quantities.

  (This does not include propagation pattern or polarization, which are determined by the physical construction of the antenna)
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• For a given amount of power sent into an antenna from the transmitter
  some will go out as radiation, and some will be reflected back from the feedpoint to the transmitter.
  ,,, gamma
• The VSWR (voltage standing wave ratio) is proportional to the amount of reflected power
  that is created in the feedline by the reflected power
• The reflected power does a couple of things:
  it creates a SW
  it can create common mode current
  ???

• got these eq from some forum. Exercise to derive them later...
  E_max = [sqRt] (P * w_(VVSWR) * R )

  
  I_max = [sqRt] { (P - w) / R }