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Radiation Resistance Explained


Radiation Resistance (in terms of 位)

Definition

Radiation resistance represents how effectively an antenna radiates power. It can be expressed in terms of wavelength (位).

Formula (Short Dipole)

For a short dipole antenna (l ≪ 位):

Rr = 80蟺² (l / 位)²

Simplified Formula

Rr ≈ 790 (l / 位)²

Since 80蟺² ≈ 790

Half-Wave Dipole

For a half-wave dipole antenna:

Rr ≈ 73 惟

Example

If l = 位 / 10:

Rr = 790 (1/10)²
Rr = 790 × 0.01
Rr = 7.9 惟

Summary

  • Depends on (l / 位)²
  • Larger antenna → higher radiation resistance
  • Important for antenna design
  • Short dipole: Rr = 80蟺² (l / 位)²
  • Approx: Rr ≈ 790 (l / 位)²
  • Half-wave dipole: ≈ 73 惟

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