Disciplines for Microwave Heating
Date: Spring 2012
One of my students has asked which discipline (physics, mechanical engineering, electrical engineering, communications engineering, .....) is most involved in the design of microwave heating solutions. I have asked experts in all four fields and they all seemed puzzled and unaware of the answer. Who designs microwave heating equipment?
In modern science and engineering, the distinctions between academic
disciplines are very blurred. There is a strong focus on
inter-disciplinary studies because so many disciplines are needed to
design everyday things. For example, a home microwave includes
chemical engineers (who design the materials), mechanical engineers
(who design structural parts made from the materials), electrical
engineers (who design the circuitry), industrial engineers (who design
the appearance and functionality), physicists (who invented the
magnetron powering the microwave source).
I would say that many disciplines are necessary -- and as such, it is
hard to judge one as the "most" important. A little like the old
argument "which system in the body is most important?" -- when in
reality, without the any of the nervous, circulatory, endocrine,
skeletal, or other systems, we would die! Without all these fields
working together, we would not have a microwave...
Hope this helps,
Several disciplines will be involved, but the bulk of the design work lies within the field of electrical engineering, specifically an “EE” trained in microwave engineering. This specialty within electrical engineering focuses on high frequency electromagnetics—the generation of it, the transmission of it, and in this case, the absorption of it within materials. A microwave engineer (again, a specialty of EE), will often work in RADAR and microwave communications (satellite communication) as well as microwave heating. Other support fields can be included: a mechanical engineer to design any mechanical hardware needed; a power engineer (another EE) to design any support power needed for driving the microwave electronics, and a digital and/or analog design engineer (EE) to design the control electronics. Outside of simple commercial applications (a microwave oven, for example), other specialties can be involved. An Applied Physicist or a Material Scientist might get involved if there is a need for exotic interaction between microwaves and materials. In general, though, an EE trained in microwave engineering will be most involved.
Microwave heating systems are conceptually fairly simple: Just a high
power magnetron and a wave guide to conduct the high power
microwave emissions being generated into the cavity containing the
object being heated. Note that generally what the equipment is doing is
heating the water contained in the object to be heated. A 2.45 GHz
magnetron is generally used because this is a resonant frequency of
the water molecule. If the object intended to be heated contains no
water or moisture, it will not get hot.
To design such heating equipment, some basic high power, high
frequency electronic engineering experience is needed, as well as a
skilled high voltage power supply designer. However, most of the effort
requires the skills of an experienced mechanical designer to design
the heating cavity and integrate the magnetron, its power supply,
design the wave guide feed from the magnetron, and to design the
sealing system that prevents microwave leakage. Your suggestion of a
communications engineer as well as a physicist wouldn't be of much
use to this project.
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Update: June 2012