QuestenaPráctica que te muestra qué repasar después
Pregunta 199

What is the purpose of a capacitance hat on a mobile antenna?

  1. To increase the power handling capacity of a whip antenna
  2. To reduce radiation resistance
  3. To electrically lengthen a physically short antennaRespuesta correcta
  4. To lower the radiation angle

Explicación

A capacitance hat is a disc or set of spokes near the top of a short whip that adds capacitance to ground at that point, raising the current distribution along the whip and shifting its resonance downward. Electrically the antenna behaves as though it were longer, so less loading inductance is needed and efficiency improves.

Continúa con este test

Empezar la práctica
Pregunta 199: What is the purpose of a capacitance hat on a mobile… · FCC General Class (Element 3) · Questena