In the world of physics, interference means that two or more waves meet in space and create a pattern that is determined by the frequency and direction of each wave.
The easiest way to understand wave interference is to imagine two rocks thrown into a lake. Each rock creates a circular wave pattern in the water, and when the two waves meet, they fuse.
Here is a short animation of the wave interference in action:
According to classical physics, the same thing happens when three-dimensional waves meet, such as sound waves, electromagnetic waves, etc.
What is a wave?
In classical physics, a wave is a disturbance that transfers energy. Each wave has a frequency – that is, how often it “pulsates” – and from this frequency also derive the wavelength of the wave. If a wave moves through a certain unit of space per second, the frequency of the wave is 1 Hertz. If 10 wave peaks do that, we have a 10 Hz wave.
When a wave peak meets another exact wave peak (“in-phase”), they reinforce each other to create constructive interference. The end product of this is a new wave with a larger amplitude (see picture on the left). When a wave trough meets another exact wave trough (“out of phase”), they cancel each other out to create destructive interference (see picture on the right). Here is an animation of dynamic interference. The green and blue waves merge and create a constructive or destructive interderence that leads to the red wave.
People use the phone for their needs. They don’t recognize that it’s their need. You can use it for your purposes, but you have no right to disturb or insult anyone with your chatter.
Signal interference is dependent on interference
Now if we understand how waves travel in space and what happens when they meet, we can really understand how signal interference works.
Let’s say we have a smartphone. These devices typically operate in the frequency range from hundreds of megahertz to a few gigahertz (which means that their waves oscillate millions to billions of times per second, making them radio waves).
In order to block every cell phone / cell phone, a destructive signal jammer must be generated with the radio waves of this cell phone. Devices with radio interference actually saturate the room within a certain radius, whereby a radio wave exactly matches the frequency of the mobile phone. The only difference between the two waves is that they are out of phase (reverse wave – see the pictures above).
The product of this activity is a “white noise” RF wave that destroys the waves of the cell phone. Therefore, every mobile phone in the affected radius shows an announcement “No signal”.
The same principle applies to other forms of radio interference such as drone jams, WiFi and gps jammer, etc.