The Difference Between Radio Frequency and Microwave

February 18, 2017 2:51 am0 commentsViews: 831

The universe is full of electromagnetic (EM) radiation, and it happens in a wide range of frequencies. All of the light that you can see is just part of the electromagnetic radiation, and that is a very small part of the whole spectrum.

Note that EM radiation is not the same thing as the radiation that comes from radioactive materials; most of it is beneficial, and essential to life on this planet. To understand how this works, we have to understand what frequency means in this context.

Radio Frequency and Microwave

Frequency And Wavelength

EM radiation travels in waves, and how quickly those waves oscillate from peak to peak is how we measure their frequency. If there are 1,000 cycles per second, then we call that a kilohertz, and one million cycles per second are one megahertz.

Radio frequencies in common use range from 30 kilohertz to 3000 MHz. When they oscillate much faster, they appear as visible light, at frequencies between 400 and 790 terahertz, or 400,000 to 790,000 megahertz.

Microwave signals is at the higher end of the radio wave scale, from 300 MHz to 300 GHz (300,000 MHz). These are all radio waves, and broadcast television uses this range too, but the higher frequencies that we call microwaves have interesting properties that lower-frequency waves don’t have.

Microwaves Are Different

Microwaves can, of course unlike integrated assemblies, be used to heat food. One brand name for one of the earliest microwave ovens was Radar Range, because the frequencies that it used was so close to the frequencies that some radars use. Microwave frequencies are used for Air Traffic Control radar, naval navigation, and speed law enforcement.

Unlike radio waves at lower frequencies, microwaves don’t bounce off of the ionosphere, or travel as ground waves around the curve of the earth. They operate strictly on a line-of-sight basis, though they can travel a short way through most walls. We use them for cell phones, WiFi, satellite communications and television, and the Global Positioning System (GPS).

Radio Astronomy

Most radio telescopes operate in the microwave band. This is almost all passive reception of microwave radiation, but active radar work has been done in the solar system, such as measuring the distance to the moon and mapping the surface of Venus beneath its cloud cover.

The largest ground-based astronomical installation so far, the Atacama Large Millimeter Array in Chile, uses more than 66 dish antennas to receive microwave signals.

Wireless Power Transfer

Microwaves can be used to transmit enough power for the receiver to capture it and convert it to electricity. This would be useful for applications like recharging cell phones, but it’s impractical because the transmitter must be focused on the receiver.

Research continues on improving this, because it would be a good way to transmit power from a satellite solar energy station to a station on the surface.

Our takeaway points from this:

  • Microwaves are radio waves from a specific part of the radio wave spectrum.
  • Microwaves behave differently than other radio waves.
  • We use radio frequencies, including microwaves, for communication.

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