CHAPTER 3. HOW PHONIC COMMUNICATION WORKS
In today’s world of astonishing technology, communicationhas become very easy by just dialling
the number, we are able to talk and communicate withanyone anywhere around the globe and
also beyond the earth. Also, communication has playeda very important part in the industrial
revolution and will continue to be important so inthis chapter, let us see how are you able to
talk to anyone anywhere by just a small device mobilephone,
When one calls the other and the other talks backthe phone works as a two-way radio system
which consists of a radio transmitter and radio receiver.When you call and speak in phone you
are giving a pressure signal to the mic of phone whichhas a transducer in it which converts
pressure signal to digital electric signal which arefurther converted to radio waves and
transmitted via radio antenna to the receiver whomyou called the radio waves to travel from
one antenna to other, which are received by radioreceiver in his mobile phone then converted
to digital and further to pressure signal by speakerof phone and voice is heard by the receiver
and then he speaks and the same process happens.
This transfer of signal takes place through radiowaves. Radio waves transfer digitized signals in
the form of electric and magnetic oscillating fieldsknown as electromagnetic fields (EMF) which
travel at the speed of light. Radio waves are emittedin all directions and not only in the direction
of cell tower only, so waves are reflected and absorbedby many surfaces before they are
received by tower and thus when you keep phone closeto your ear almost half of the emitted
energy is absorbed are by your head and hence muchof the EMF are wasted. Similarly when
the signal is transferred to the receiver from celltower signal is emitted in all directions and
hence signal here to get absorbed and reflected bymany surfaces before received by cell
phone and that is why cell tower is placed in an openarea so that signal can travel in all
directions without disturbance.
An antenna is a very important component for communicationbecause, without it, it is not
possible to transmit radio waves from one place toanother. An antenna converts the electrical
signal from cell phones to radio waves because radiowaves have comparatively large
wavelengths so it does not get absorbed rather itjust passes by most of the materials and in
this way waves get transmitted. An antenna is a metallicelement that contains copper,
engineered in a specific shape and size. The shapeand size depending on what frequency of
radio wave is being received or transmitted. Antennasare also present in cell phones, they
receive and transmit signals from phones during acall. In earlier times phones used to have
large antennas that were placed outside the phoneas an extension but now because of
nanotechnology antennas are placed inside the phones.Most phones contain one antenna but
some phones also contain multiple antennas.