Calculating Wavelength If Frequency Is Known

I get this question a lot. It’s not exactly phrased this way though. Typically it’s along the lines of “What’s the wavelength of the WiFi signals in my home or office?”

Good question and a pretty simple calculation! I do realize with a quick Google search you can look the value up but….. that takes the fun out of it J

First, let’s define wavelength. Electromagnetic radiation is sinusoidal in nature and wavelength, represented by the Greek letter lambda (λ), is a distance measurement usually expressed in meters. Wavelength is defined as the distance in meters of one sinusoidal cycle as illustrated in the figure below.

Most WiFi signals run at around 2.4 Giga Hertz (GHz) or 2.4 Billion cycles per second!

Now, in you home or office, you’ve likely got a lot of other wireless devices (microwave, ovens, cordless phones, baby monitors, etc) operating in this same 2.4 GHz frequency range. In the WiFi world, the 2.4 GHz WiFi signal range is divided into 11 channels and channels can be selected when setting up a wireless network to avoid other devices transmitting in the same frequency range.

Ok – back to our question – what’s the wavelength? Here’s how we do the calculation:

12.5 cm is approximately 4.92 inches and...... that's your wavelength.

Tektronix Oscilloscope Tutorials

I came into Electrical Engineering a different way than most - starting as a graduate student with an undergraduate degree in Microbiology. These two disciplines are slightly different - Microbiologists use microscopes and EE's use oscilloscopes :) I knew I had some catching up to do and remember one of my major goals for the summer before I started grad school was to learn how to use an oscilloscope. Fortunately I came across a free tutorial booklet from Tektronix on understanding and using an oscilloscope which made it pretty easy.

Well, even though that was over 30 years ago now, the Tektronix free tutorial materials still exist and they are even better than before. If you are starting from scratch or just want to brush up these are highly recommended. Here's a link to the tutorial page. Good stuff!