Microwave oven
The development of the cavity magnetron in the UK made possible the production of electromagnetic waves of a small enough wavelength (microwaves). American engineer Percy Spencer is generally credited with inventing the modern microwave oven after World War II from radar technology developed during the war. Named the "Radarange", it was first sold in 1946. Raytheon later licensed its patents for a home-use microwave oven that was first introduced by Tappan in 1955, but these units were still too large and expensive for general home use. Sharp Corporation introduced the first microwave oven with a turntable between 1964 and 1966. The countertop microwave oven was first introduced in 1967 by the Amana Corporation. After Sharp introduced low-cost microwave ovens affordable for residential use in the late 1970s, their use spread into commercial and residential kitchens around the world. In addition to their use in cooking food, types of microwave ovens are used for heating in many industrial processes.
Jenn-Air
The original Jenn-Air Products Company was founded by Louis J. Jenn in Indianapolis, Indiana, in 1947, later becoming simply Jenn-Air. In the early years, the company was focused on manufacturing and marketing of industrial fans for use in a variety of commercial and industrial applications. In 1961, Jenn-Air's integration of one of these fans to a cook-top range led to the invention of the first self-ventilated downdraft range. The company expanded its product line to include many other kitchen appliances including microwave ovens, refrigerators, dishwashers, and small appliances such as mixers and blenders. Unfortunately Jenn Air quality control has suffered over time. Their glass cook tops consistently degrade (under the surface), oftentimes with only a few months of normal usage. No amount of cleaning or buffing will remedy the problem. As a result, customer demand has plummeted.