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E9A03

ANTENNAS AND TRANSMISSION LINES · Basic antenna parameters: radiation resistance, gain, beamwidth, efficiency; effective radiated power (ERP) and effective isotropic radiated power (EIRP)

E9A03E9A →

What term describing total radiated power takes into account all gains and losses?

  1. APower factor
  2. BHalf-power bandwidth
  3. CEffective radiated power
  4. DApparent power
Why Effective radiated power is the transmitter output power adjusted by every gain and loss in the system: feedline loss, connector and duplexer or filter losses, and the antenna's gain referenced to a dipole. You convert everything to decibels, add the gains and subtract the losses, then apply that net dB figure to the transmitter power. ERP is what a half-wave dipole would need to be fed to produce the same signal in the antenna's favored direction; EIRP is the same idea referenced to an isotropic radiator, which is 2.15 dB higher.
Watch out Power factor and apparent power are AC power terms describing the phase relationship between voltage and current in a reactive circuit, and half-power bandwidth describes the width of a resonant response between its -3 dB points. None of them relate to radiated signal strength.
ERP = TX power + antenna gain - feedline and component losses, all in dB. EIRP is ERP plus 2.15 dB.
HamSandwich explanation, first draft. The question and answers are the NCVEC text.
← E9A02 All of E9A E9A04 →

The rest of E9A

  1. E9A01 What is an isotropic radiator?
  2. E9A02 What is the effective radiated power (ERP) of a repeater station with 150 watts transmitter power output, 2 d…
  3. E9A03 What term describing total radiated power takes into account all gains and losses?
  4. E9A04 Which of the following factors affect the feed point impedance of an antenna?
  5. E9A05 What does the term "ground gain" mean?
  6. E9A06 What is the effective radiated power (ERP) of a repeater station with 200 watts transmitter power output, 4 d…
  7. E9A07 What is the effective isotropic radiated power (EIRP) of a repeater station with 200 watts transmitter power …
  8. E9A08 Which frequency band has the smallest first Fresnel zone?
  9. E9A09 What is antenna efficiency?
  10. E9A10 Which of the following improves the efficiency of a ground-mounted quarter-wave vertical antenna?
  11. E9A11 Which of the following determines ground losses for a ground-mounted vertical antenna operating on HF?
  12. E9A12 How much gain does an antenna have compared to a half-wavelength dipole if it has 6 dB gain over an isotropic…
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