Abstract: An apparatus for a coaxial transmission line is provided. The apparatus can include a dielectric member having an inner surface defining a bore along a longitudinal axis of an inner conductor of the coaxial transmission line; and a first conductive member mounted axially around the dielectric member and extending along the longitudinal axis. A cross-section of an outer surface of the first conductive member can define a first perimeter. A cross-section of an inner surface of the outer conductor of the coaxial transmission line can define a second perimeter. The first perimeter can be smaller than the second perimeter and thereby provide clearance between a portion of the outer surface of the first conductive member and the inner surface of the outer conductor of the coaxial transmission line when the apparatus is positioned in an annulus defined by the inner conductor and the outer conductor of the coaxial transmission line.

Abstract: A radio frequency antenna for radiating electromagnetic energy into a reservoir filled with a target material, the antenna being operatively connected to a feed transmission line. The antenna includes a waveguide, at least one slot formed in the outer waveguide layer, and a sleeve portion enclosing at least a portion of the waveguide. The sleeve portion comprises at least first and second dielectric layers where the permittivity of the second dielectric layer is higher than the permittivity of the first dielectric layer and the first dielectric layer is positioned in closer proximity to the waveguide than the second dielectric layer. When the antenna is inserted into the reservoir, the input impedance of the antenna remains matched to the feed transmission line for a wide range of target materials.

Abstract: An apparatus and method for the extraction of hydrocarbons from an underground reservoir using a well is disclosed. The apparatus comprises a power source operable to supply periodic electrical power at a first frequency; at least one impulse generator unit operable to convert the periodic electrical power at the first frequency into periodic electrical power at a second frequency and to couple electromagnetic energy generated by the periodic electrical power at the second frequency into the reservoir, the second frequency being at least ten times higher than that of the first frequency; and a conducting cable being operatively coupled between the power source and the at least one impulse generator unit.