ABSTRACT
Both microwave (MW) and radio frequency (RF) heating
(also referred to as dielectric heating) refer to the applica-
tion of electromagnetic waves to generate heat at regulated
frequencies. The frequencies regulated by the U.S. Federal
Communications Commission (FCC) for industrial, medi-
cal, and scientific purposes are 13.56, 27.12, and 40.68
MHz for RF, and, 915, 2450, 5800, and 24,125 MHz for
MW applications, respectively. Aside from the frequency
range and penetration depth, RF and MW heating differ in
the nature of the generators and applicators used. RF heat-
ing is more appropriate for materials of regular shape, large
dimensions, and high loss factor, while MW heating is
better adapted for compact materials with complex shapes
and low loss factor.[1] Particularly, RF heating provides
uniform heating because of its ability to penetrate deeper
into the product with uniform field patterns, rather than the
complex non-uniform wave patterns found in the MW
oven. Continued public concerns about food hygiene issues
and demand for conveniently packaged foods with
enhanced nutritional quality can require rapid heating
alternatives with high penetration power into the product.
