In 1945, the heating effect of a high-power microwave beam was accidentally discovered by Percy Spencer, an American self-taught engineer from Howland, Maine. Employed by Raytheon at the time, he noticed that microwaves from an active radar set he was working on started to melt a chocolate bar he had in his pocket. The first food deliberately cooked with Spencer's microwave was popcorn, and the second was an egg, which exploded in the face of one of the experimenters.[10][11] To verify his finding, Spencer created a high density electromagnetic field by feeding microwave power from a magnetron into a metal box from which it had no way to escape. When food was placed in the box with the microwave energy, the temperature of the food rose rapidly. On 8 October 1945, Raytheon filed a United States patent application for Spencer's microwave cooking process, and an oven that heated food using microwave energy from a magnetron was soon placed in a Boston restaurant for testing.[12]

Frozen dinners, pies, and microwave popcorn bags often contain a susceptor made from thin aluminium film in the packaging or included on a small paper tray. The metal film absorbs microwave energy efficiently and consequently becomes extremely hot and radiates in the infrared, concentrating the heating of oil for popcorn or even browning surfaces of frozen foods. Heating packages or trays containing susceptors are designed for a single use and are then discarded as waste.
Different microwaves are designed for different locations. A countertop microwave sits on top of your kitchen counter. An under-cabinet microwave is mounted beneath your drawers-cabinet-organizers/4044_623679_1032619_1075864'>kitchen cabinets, keeping your counter space clear. An over-the-range microwave is mounted over a range or stove. Microwaves of this type often have built-in exhaust fans and lights.
Preprogrammed cooking functions use sensors and/or preset power levels and times to cook a variety of foods, including popcorn, potatoes, beverages, vegetables, and frozen meals. The sensors detect how much steam is emitted from the cooking food, but they aren’t always accurate. Franke said, “A lot depends on the skill of the person who’s programming it.” In our tests, the accuracy of these functions varied from model to model.
This is a great microwave for power users who want complete control over their cooking — those often frustrated with overcooked leftovers or constantly sticking their finger in to check for cold spots. We didn’t mind spending a little extra time learning the features and extras we came to value, but it could be overkill for the average user looking for a familiar design.
Microwave doors generally come with either push-to-open buttons or handles, and they open either to the right or to the left. We’re fans of the door handle version, which allows you greater control and is easier on the long-term fate of the door. However, when it comes to direction make sure you note if you need a right-opening microwave to fit your kitchen’s layout.
The most shocking revelation in all of our research was the fact that among the hundreds of microwaves for sale today, many have completely identical hardware. Like, exactly the same—except for slightly different keypads and brand-name badges. This is because most of the microwaves in the world are produced by only a handful of manufacturers. But we also learned that even if the housing looks exactly the same, the way the models are programmed can still make a big difference in performance between seemingly identical microwaves.

We talked to Bob Schiffmann, President of the International Microwave Power Institute for 18 years, who has worked with microwaves since the 1960s and consulted for frozen food companies. He told us that cheaper microwaves use cheaper components and end up costing more to fix than they’re worth. By digging through reviews and crunching some numbers, we found that the risk of buying an unreliable microwave doubles (at a minimum) once you go below that $100 mark. We didn’t consider anything under that price.
^ "Efficient" here meaning more energy is deposited, not necessarily that the temperature rises more, because the latter also is a function of the specific heat capacity, which is often less than water for most substances. For a practical example, milk heats slightly faster than water in a microwave oven, but only because milk solids have less heat capacity than the water they replace.[citation needed]
It’s a rare compact model that comes equipped with 10 power levels, but this AmazonBasics model offers them. It also has Alexa voice control, which feels almost too futuristic for a microwave. You save on space without giving up much of anything with this model, which we call a solid win! This 0.7 cubic ft microwave is awesome and worth the counter space. The control panel is easy to use and laid out well.
“What is microwave radiation? Is it dangerous? Are microwaves safe?” We see these questions a lot, so let’s clear it up once and for all: this type of electromagnetic radiation can be dangerous at high levels, but we’ve been using microwaves for decades, and it’s never been a problem. This is because, from the mesh door to the locking mechanism, microwaves are specifically sealed to prevent radiation from escaping, and the design works really, really well. However, if your oven door is damaged or if you think something is wrong, call a contractor and have them test radiation levels. It only takes a few seconds, and then you’ll know for sure.
All microwaves use this same core technology, but today, there are many models available that come with a variety of additional features. For instance, many products have pre-programmed settings to cook common foods, as well as various cooking methods, such as steaming and grilling. Depending on what size and features you want, you can spend anywhere from $20 to $2,000 on a new microwave. 
There are three main styles of microwaves, and they’re distinguished predominantly by where and how they’re installed. First, there are your standard countertop microwaves, which simply sit on the kitchen counter and are plugged into an electrical outlet. This style is often the least expensive and works best for anyone who lives in a rented home, as they can be moved easily. Countertop microwaves are also a good option if you don’t want to remodel your kitchen to accommodate a built-in style. 
A microwave oven heats food by passing microwave radiation through it. Microwaves are a form of non-ionizing electromagnetic radiation with a frequency in the so-called Microwave Region (300 MHz to 300 GHz). Microwave ovens use frequencies in one of the ISM (industrial, scientific, medical) bands, which are otherwise used for communication amongst devices that don't need a license to operate, so they do not interfere with other vital radio services.
For most people, microwaves are a must-have kitchen appliance for meal prep. Whether you want to popcorn or a warm bowl of soup, a microwave will get the job done in mere minutes. Plus, there's nothing to preheat, which helps you conserve energy in your home. Their convenience and ease of use are what make microwaves a staple for most modern households.

Frequently used microwaves need to be cleaned at least once per week, because any food remnants stuck to the walls can get overheated and cause damage to the microwave itself. A simple trick (courtesy of Wirecutter deputy editor Christine Cyr Clisset) is to nuke a bowl of water for a few minutes on high: The steam will loosen most gunk, and you can wipe it out with just a plain paper towel or a sponge. For cleaning the outside of a microwave, Good Housekeeping recommends spraying cleaner onto a towel and not on the actual surface, where it can get into the perforations and damage the internal elements.
Panasonic uses a supposedly superior power-regulating mechanism called an inverter, which can deliver continuous heating at varying strengths—50 percent power, for example, means continuous delivery at 50 percent of the unit’s max. Most other manufacturers use a cheaper and more common technology, a transformer, which means that it delivers 50 percent power by cycling between periods of full power and zero power. Panasonic’s inverter technology is supposed to cook more evenly, but Franke told us, “I’ve never found that [an inverter] necessarily means the oven performs better.” The Panasonic models we tested cooked potatoes and frozen meals well, but they overcooked the edges of frozen ground beef using the defrost mode. In the end, we don’t think paying more specifically for inverter technology is worth it.
A microwave oven (commonly referred to as a microwave) is an electric oven that heats and cooks food by exposing it to electromagnetic radiation in the microwave frequency range.[1] This induces polar molecules in the food to rotate and produce thermal energy in a process known as dielectric heating. Microwave ovens heat foods quickly and efficiently because excitation is fairly uniform in the outer 25–38 mm (1–1.5 inches) of a homogeneous, high water content food item.
×