Headphones have become an essential part of our life. But how do headphones act as antenna? Interested to know? Then read on…
Modern mobile phones don’t have sufficient space for an antenna. But you can easily attach headphones to your mobile phone. They will do the same work as the antenna.
But you might be wondering: how do headphones act as an antenna? Headphones have insulated metal wires whose one end has a coil surrounding the magnet, and the other has a thick metal jack. It works as an antenna by picking up energy from radio waves and supplying it to the tuner.
The headphones are usually 35 inches in length and are the best choice for picking frequency modulation (FM) signals.
Why Does My Phone Not Automatically Capture FM Radio?
You may feel irritated when your mobile phone asks you to put on headphones whenever you try to access FM radio. Your phone can communicate with people anywhere over the World but cannot create an efficient way of listening to radio waves which sounds a bit fishy, but it is true.
How Radio Waves Work
Radio waves move from the transmitter to the receiver wirelessly or through the air. First, you need to capture the sound energy from a recording (through a microphone) which also converts the sound energy into electric energy.
A long antenna in the transmitter boosts this energy. After boosting the electric energy, it is sent with the speed of light in the form of radio waves and received by the receiver’s antenna.
The antenna then converts the radio waves into an electric current. The sound energy is decoded from the electric current, and finally, you can hear the sound of music from the radio.
Why You Need A Receiver Antenna
If you want to listen to FM radio on your mobile phone, you will not find a receiver antenna. That’s why you need headphones that will act as a receiver antenna.
But recent mobile phones have developed internal antennas, and it’s even possible to listen to FM radio without headphones. You can even do it at home. But for this, you need a safety pin.
First, you need to press the safety pin on its sides so that it can easily fit on the headphone jack of your mobile. Then you can open the FM radio on your mobile phone and set a channel.
Why Does Radio Require Two Types Of Antenna?
An antenna is nothing but a metallic conductor. A modern transistor radio has two types of antennae. One antenna is inside the radio, and the other extends externally.
Now the question comes, why do you need a separate antenna in a radio? It is because the radio emits two different wave frequencies. The first one is amplitude modulation (AM) frequency, and the second one is frequency modulation (FM).
Let me tell you the differences between these two frequencies.
- The frequency modulation waves can travel a shorter distance but at a high frequency. The frequency ranges from 85-100 MHz.
- The amplitude modulation waves can travel a greater distance but with low frequency. The frequency can be 1000KHz.
So, you can see that the frequency modulation signals have ten times greater frequency than amplitude modulation signals. A single antenna can’t pick two different high frequencies.
How Do Headphones Act As Antenna?
The length of your antenna depends on the frequency of the radio wave. So, you need a long antenna to catch a high wavelength. For example, if the frequency is 85MHz, then the antenna length should be at least 35 inches. Earphones have about the same length and are a perfect alternative to a phone antenna.
Almost all mobile phones available in the market include primary headphones and have an inbuilt antenna. But the inbuilt antenna is just a few inches in length and is insufficient to receive the frequency modulation waves.
Headphones are almost half the wavelength of FM radio, and they serve as an antenna that helps you listen to the audio from FM radio. Those mobile phones, which have an inbuilt radio antenna, are a bit bulky because the antenna increases the phone’s thickness.
You might like to read: Why Do My Headphones Keep Changing Volume
Answers To More Questions On Headphones And FM Radio
#1. Do headphones improve the signal?
Yes, the headphones improve the signal. If you are using headphones, you can hold your mobile away from the head for a better signal. You can even hold your phone out of your window.
#2. Why do you need earphones for the radio?
The FM radio has a wavelength between 2.5 to 3.5 meters. An antenna that will half the wavelength is sufficient in receiving the signal. The headphones available in the market is roughly that length, and you can use them not only as an antenna but also in receiving the sound from your mobile to headphone.
#3. What kind of signal comes out of headphones?
The headphones are electrostatic transducers. Hence, they convert the electric signal into sound energy by which you can listen to the audio properly.
#4. Can my headphones pick up radio waves?
Yes, your headphones can pick up the radio waves from a short wave radio station. When the radio waves pass by, it excites the electrons within the antenna and creates an electric signal. The speakers within the wireless headphones receive the electric signal and produce the final audio.
#5. What causes poor signal strength?
Poor signal strength is a problem that is simply beyond your control. The reasons can be the way your house is constructed, how far you are from the nearby network source. It might also happen if you try to connect too many devices to the same network at once.
#6. Do 3.5 antennas work?
The phone manufacturers opt to use headphones as an antenna because the coiled antennas are not efficient. It even reduces the cost and size of the device. However, a wire length with a 3.5mm jack on end will work similarly to headphones.
Headphones Are Natural Antennas
Headphones have become a vital part of our life. You use them daily for listening to songs, watching videos, or focusing on some essential things. However, you can also use it as an antenna and listen to the FM radio.
I hope this article has helped you know how headphones act as an antenna so that you can listen to your favorite FM channel easily.
Please do share your suggestions for this article.