- #1
ap_cycles
- 36
- 1
Hi,
I come across these 2 questions on a website:
1. Why are the antenna on TV and Radios about the same length
2. Why is the antenna on the cellphone (i.e. the older versions) smaller than the Radio antenna?
My answers to these 2 questions are: Firstly, the waves that the cellphone detect are of a smaller wavelength than those detected by the radio or TV. If i am not wrong, the wavelength of an antenna is about one quarter the wavelength of the wave it receives.
Secondly, the amplitude of the waves. One can argue that the longer the antenna, the bigger will be the amplitude of the wave it receives. The max amplitude (i.e. max energy) the cellphone receives is smaller than that received by the TV or radio?
What do forummers think of my answers? I am quite confident of my 1st, though not so sure about the 2nd. Btw, i am a high school physics teacher about to deliver this topic on EM radiation soon. :shy:
(Off topic: do most modern cellphones have an antenna anyway? IF the answer is yes, won't hiding them within the chasis of the phone defeat the original purpose of a protruding antenna?)
I come across these 2 questions on a website:
1. Why are the antenna on TV and Radios about the same length
2. Why is the antenna on the cellphone (i.e. the older versions) smaller than the Radio antenna?
My answers to these 2 questions are: Firstly, the waves that the cellphone detect are of a smaller wavelength than those detected by the radio or TV. If i am not wrong, the wavelength of an antenna is about one quarter the wavelength of the wave it receives.
Secondly, the amplitude of the waves. One can argue that the longer the antenna, the bigger will be the amplitude of the wave it receives. The max amplitude (i.e. max energy) the cellphone receives is smaller than that received by the TV or radio?
What do forummers think of my answers? I am quite confident of my 1st, though not so sure about the 2nd. Btw, i am a high school physics teacher about to deliver this topic on EM radiation soon. :shy:
(Off topic: do most modern cellphones have an antenna anyway? IF the answer is yes, won't hiding them within the chasis of the phone defeat the original purpose of a protruding antenna?)