Beam steering refers to the changing of the direction of the wave lobe that contains the maximum power of a radiation blueprint. This is the lobe that displays the greatest field strength, which basically means the one with the best reach and the strongest of signals. Take radio waves for instance.
Radio is a system of signals broadcast through the modulation of electromagnetic waves which have wave patterns below that of perceptible and detectable light waves. Electromagnetic radiation travels by means of fluctuating electromagnetic fields that are transmitted through the air. Through this system, information is carried through different areas by systematically changing properties of the radio waves. Examples of these properties are phases, frequencies and amplitudes. When radio waves pass through an electrical conductor, the alternating fields create an irregular current in the conductor. This can be altered and formed into sound waves or other types of signal waves that efficiently and effectively convey raw data.
These waves, generated by antenna radiation systems, carry the precise signals that will be converted by radio transistors into sound bytes and other types of audio information. In short, radio waves are what make it possible for you to hear music, news and advertisements in your radio component. To reach more audiences in far-away places, technical specialists adjust the beam steering mechanisms in their transmitters.
For beam steering to take place in the case of radio wave transmitters, switching antenna elements is necessary. Another way to do this is to change the relative phases of the driving element's radio frequency signals. It is important to note, however, that there are some electromagnetic radiations that have higher frequencies rate than radio frequency. Examples of these high frequency waves are microwaves, gamma rays, ultraviolet, infrared and X-rays. Many of these are used in the day to day tasks of people like you.
Beam steering can also be applied in terms of optical systems. This is significantly done by modifying the refractive index of the specific medium, through which the optical beam is transmitted. A simple component like a normal prism is one of the main tools for beam steering optical laboratory experiments.
Beam steering can also be applied in terms of ultrasound systems. To be able to steer these kinds of sound waves, a special kind of device is used to tap into the ultrasound linear arrays. Once tapped, minor tweaks can alter the whole flow of the ultrasound, enabling the process we call beam steering.
The Reciprocity Theorem is related to beam steering, and further reading about this theory is advised for those people who want to delve further into the topic. Immersing into several articles regarding antenna, phase arrays and other mathematical indexes related to radiation and different wave frequencies can also greatly assist you in understanding the basics and fundamentals of beam steering.