Patent ID: 6617557
Filing Date: 2003-09-09
Classification: B29C,B29K,C08L,C09D,C09J,Y10T

Abstract:
An apparatus for heating a composition using radio frequency (RF) energy, comprising:a direct current (DC) voltage source; an RF amplifier coupled to the DC voltage source, wherein the DC voltage source provides DC voltage to the RF amplifier; an impedance matching circuit coupled to an output of the RF amplifier; a first elongated electrode connected to a first node within said impedance matching circuit; a second elongated electrode connected to a second node within said impedance matching circuit; and signal generating means, coupled to the RF amplifier, for generating an RF signal, wherein a first portion of the first electrode and a first portion of the second electrode are adjacent to and substantially parallel with each other, a second portion of the first electrode is angled in a direction away from the second electrode, said second portion of the first electrode being between said first portion and an end of the first electrode, a second portion of the second electrode is angled in a direction away from the first electrode, said second portion of the second electrode being between said first portion and an end of the second electrode, and when the RF amplifier amplifies the generated RF signal and the amplified RF signal is provided to the impedance matching circuit, a stray electromagnetic field is generated in a region above the space between said first portion of the first electrode and said first portion of the second electrode, whereby the generated stray field can be used to heat the composition when the composition is placed in said region.