Microwave ovens are high voltage, high power, potentially hazardous pieces of equipment that use short bursts of RF energy for heating. In the United States, the FCC regulates the frequency and power levels that manufactures use with their microwaves. Residential microwaves radiate at 2.4 GHz and commercial microwaves typically radiate at 900 MHz. Commercial microwaves have two magnetrons and residential units have just one. The also occupy more bandwidth during each burst, which can potentially cause more interference to nearby wireless networks than their residential equivalents.
In the short video below, an iPad displays the pulsed RF energy measured with WiPry-Combo when a microwave oven heats up a bag of microwave popcorn. The waveform consists of RF pulses, and lastly the pulses stopping after the microwave finishes cooking.
Use Power Meter to Learn How Microwave Shortcuts Work
WiPry-Combo’s peak power meter lets users investigate how their kitchen microwave oven cooks food – including microwave popcorn! There are all kinds of stuff that people cook with their microwave. Some of the newest models have “shortcuts” built-in that let people reheat casserole, defrost a pound of chicken or beef, or just warm up a glass of water for tea. How do the different modes work? Well, one idea to find out is to try the oven’s different options and use WiPry-Combo to look at each mode's pulsed RF waveform. The RF frequency doesn’t change – the inside of the microwave oven is just a commercialized resonant cavity, but the pulse width and duty cycle may change according to what’s cooking.