What Is the Ideal Length for a Half Wave Dipole Aerial at 120MHz?

[Sanosuke Sagara]

Here's the question,

A half wave dipole aerial is used to receive FM waves of frequency 120MHz.What is the most effective length of the aerial?

(Speed of electromagnetic waves =3.0 x 10^8)


I can't understand with the word 'half wave dipole aerial' ,is that means vibrations in air column,in an open end tube or both end-opened tube ?

wavelength = 3 x 10^8 / (120 x 10^6)
= 0.025m

then I get stuck here,cannot find the lenght.



Can anybody help me ?

 

[ZapperZ]

Here's the question,

A half wave dipole aerial is used to receive FM waves of frequency 120MHz.What is the most effective length of the aerial?

(Speed of electromagnetic waves =3.0 x 10^8)


I can't understand with the word 'half wave dipole aerial' ,is that means vibrations in air column,in an open end tube or both end-opened tube ?

wavelength = 3 x 10^8 / (120 x 10^6)
= 0.025m

then I get stuck here,cannot find the lenght.



Can anybody help me ?

A half-wave dipole antenna or aerial means that the whole length of the aerial equals to half of the wavelength. This is similar to having a fundamental wavelength in a standing wave air tube with both ends being open.

Zz.

 

[wais]

I completely understand your confusion with the question. A half wave dipole aerial is a type of antenna used to receive radio signals. It is made up of two equal length conductors, with one end connected to the center of the radio receiver and the other end connected to the ground. The term "half wave" refers to the length of the antenna, which is half the wavelength of the radio waves it is designed to receive.

In this case, the FM waves have a frequency of 120MHz, which corresponds to a wavelength of 0.025m, as you correctly calculated. Since the half wave dipole aerial is designed to receive waves with a wavelength of 0.025m, the most effective length of the aerial would also be 0.025m.

I hope this helps clarify the question for you. If you have any further questions, please don't hesitate to ask.