Abstract: A susceptor composition that can bond two or more layers or substrates to one another and that can be used to coat or cut a substrate. The susceptor composition is activated in the presence of radio frequency (RF) energy. In one embodiment, the susceptor composition of the present invention comprises a susceptor and a carrier. The carrier and susceptor are blended with one another and form a mixture, preferably a uniform mixture. The susceptor is present in an amount effective to allow the susceptor composition to be heated by RF energy. In a preferred embodiment, the susceptor also functions as an adhesive. The susceptor is an ionic or polar compound and acts as either a charge-carrying or an oscillating/vibrating component of the susceptor composition. The susceptor generates thermal energy in the presence of an RF electromagnetic or electrical field (hereafter RF field).

Abstract: An RF heating system for bonding a first element to a second element. In one embodiment, the RF heating system includes: (a) a composition, which functions as an adhesive, interposed between the first and second elements, the composition including an ionomer and a polar carrier, wherein the ionomer and/or the carrier are present in amounts effective to allow the composition to be headed by a fringe RF field; and (b) a radio frequency (RF) heating apparatus for producing the fringe RF field.

Abstract: An RF heating system. In one aspect of the present invention, the RF heating system includes a first elongated electrode connected to a first node within an impedance matching circuit and a second elongated electrode connected to a second node within the impedance matching circuit, wherein (a) a first portion of the first electrode and a first portion of the second electrode are adjacent to and substantially parallel with each other, (b) a second portion of the first electrode is angled in a direction away from the second electrode, (c) a second portion of the second electrode is angled in a direction away from the first electrode, and (d) a stray electromagnetic field is generated in a region above the space between the first portion of the first electrode and the first portion of the second electrode, whereby the generated stray field can be used to heat a composition when the composition is placed in the region.

Abstract: A susceptor composition that can bond two or more layers or substrates to one another and that can be used to coat or cut a substrate. The susceptor composition is activated in the presence of radio frequency (RF) energy. In one embodiment, the susceptor composition of the present invention comprises at least one ionomer and a polar carrier. The ionomer and polar carrier are blended with one another and form a mixture, preferably a uniform mixture. The ionomer and polar carrier are present in an amount effective to allow the susceptor composition to be heated by RF energy. Also disclosed are RF induction heating systems.

Abstract: A susceptor composition that can bond two or more layers or substrates to one another and that can be used to coat or cut a substrate. The susceptor composition is activated in the presence of radio frequency (RF) energy. In one embodiment, the susceptor composition of the present invention comprises a susceptor and a carrier. The carrier and susceptor are blended with one another and form a mixture, preferably a uniform mixture. The susceptor is present in an amount effective to allow the susceptor composition to be heated by RF energy. In a preferred embodiment, the susceptor also functions as an adhesive. The susceptor is an ionic or polar compound and acts as either a charge-carrying or an oscillating/vibrating component of the susceptor composition. The susceptor generates thermal energy in the presence of an RF electromagnetic or electrical field (hereafter RF field).

Abstract: A susceptor composition that can bond two or more layers or substrates to one another and that can be used to coat or cut a substrate. The susceptor composition is activated in the presence of radio frequency (RF) energy. In one embodiment, the susceptor composition of the present invention comprises a susceptor and a carrier. The carrier and susceptor are blended with one another and form a mixture, preferably a uniform mixture. The susceptor is present in an amount effective to allow the susceptor composition to be heated by RF energy. In a preferred embodiment, the susceptor also functions as an adhesive. The susceptor is an ionic or polar compound and acts as either a charge-carrying or an oscillating/vibrating component of the susceptor composition. The susceptor generates thermal energy in the presence of an RF electromagnetic or electrical field (hereafter RF field).

Abstract: A power amplifier that provides wide-band, high efficiency, high voltage, HF power amplification over a large dynamic operating range. In one embodiment, the power amplifier includes a driver amplifier, an intermediate power amplifier comprising a coherently combined array of two transistors, and a final power amplifier comprising a coherently combined array of multiple transistors. The two stage driver amplifier drives the intermediate power amplifier, which drives the final power amplifier. Preferably, because of the inherent linearity, dynamic range, and power limiting requirements, the driver amplifier includes two transistor devices that are of the silicon power bipolar type, operating in class A with classic common-emitter circuit configuration. Preferably, the transistors used in the intermediate power amplifier and the final power amplifier are MOSFETS operating in a non-classic DC grounded-drain, RF common source circuit configuration.

Abstract: A high-power high-voltage transistor has four or more semiconductor dies mounted in thermal contact on a metal flange. Each die has a flat lower surface with a drain (collector) region formed over at least 80 percent of its lower surface. A gate (base) region and a source (emitter) region are formed respectively on upper surfaces of the die. The drain region is seated in direct electrical and thermal contact with the flange, so that the flange serves as a drain lead for the transistor die. The die has a drain-source breakdown voltage or collector-emitter breakdown voltage) on the order of one kilovolt or higher and an area of one hundred thousand square mils or larger. Molybdenum tabs between the drain (collector) region and the flange protect the die from thermally-induced stresses. The dies can be MOSFET power transistors, bipolar junction transistors or other solid-state devices. An oval lead frame can be employed for connecting to the source regions.

Abstract: A high-power RF feedback resistor assembly includes a flat film resistor or other flat device mounted in thermal communication onto a bushing which is, in turn, mounted directly onto a cooling flange of an associated power transistor. A bushing has a vertical bolt hole through it to receive a threaded screw. The bushing can have a cutout beneath the flat vertical surface on which the resistor is mounted to provide clearance for a printed circuit board.