What is RF (Radio Frequency) and it’s Uses?

In this tutorial, we are going to learn about RF (Radio Frequency) and Its Uses.

RF (Radio Frequency) –

  • Its refer to energy which frequency is high enough to radiate , which has range between about 20Khz to 300Ghz.
  • RF can also be conducted through cables / conductor like as cable television signals and between circuit components.
  • The frequency of an RF signal often depends on the application.

Uses of RF:

1.Transfer Information.

  • Most common use of RF is to transfer information without wires.
  • To transfer information, we change something about the field we are generating this is called modulation.
  • In Morse code, we turn the RF on and off.
  • In amplitude modulation (AM), we change the strength of the RF.
  • In frequency modulation (FM), we change the frequency of the RF.
  • Most modern technologies use more complicated modulation to send digital information (Wi-Fi, cellular etc)

Below are the devices which are working on transfer information.

  • Radio
  • Broadcast TV
  • Cable TV
  • Wi-Fi
  • Cellular
  • Bluetooth
  • Satellites / GPS

2. Sensing with RF

  • RF can be used to sense objects like transmit RF, see what comes back.
  • Most common example is radar.
  • Other common examples, Body scanner and motion detectors.
  • RF can also be used to measure materials.

Below are the devices which are working on sense / detect objects.

  • Radar
  • Body Scanners
  • Materials measurement

Heating objects with RF:

  1. Microwave Oven
  2. Inside a microwave oven, RF is generated by a magnetron; Frequency is 2.45 GHz, about the same as Wi-Fi.
  3. RF penetrates food or liquid, causing molecules (especially water) to vibrate.
  4. If metal is in the microwave, the radiated RF can turn back into conducted RF (electricity), causing sparks, fires etc.
  5. RF is often used for heating in industrial applications like as pasteurizing milk.
  6. Can be used for medical application.

Aside: RF safety

  • X- rays, gamma rays, and UV are ionizing radiation like it can break up atoms / molecules (including DNA) cause cancer etc.
  • RF energy is non ionizing radiation, it does not break atoms / molecules apart.
  • RF is not dangerous under normal conditions, only very high power transmitter require caution.

RF Test and Measurements:

  • Used by people who design, test, manufacture and debug devices that use RF.
  • Basic categories of RF instruments:
  • Spectrum analyzer
  • Signal generator
  • Network analyzer
  • Power sensors

About EEE

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