Abstract: An RF antenna assembly may be positioned within a wellbore in a subterranean formation for hydrocarbon resource recovery. The RF antenna assembly includes first and second tubular conductors and a feed structure therebetween defining a dipole antenna to be positioned within the wellbore, and an RF transmission line extending within one of the tubular conductors. The feed structure includes a dielectric tube, a first connector coupling the RF transmission line to the first tubular conductor, and a second connector coupling the RF transmission line to the second tubular conductor.

Abstract: A radio frequency (RF) antenna assembly configured to be positioned within a wellbore in a subterranean formation for hydrocarbon resource recovery may include an RF transmission line and an RF antenna coupled to the RF transmission line. The RF antenna assembly may also include an adjustable balun that may include a tubular balun housing surrounding the RF transmission line and defining a space therebetween. The adjustable balun may further include an adjustable shorting body slidably movable within the space and contacting the tubular balun housing and the RF transmission line at an adjustable shorting position.

Abstract: An apparatus is provided for heating a hydrocarbon resource in a subterranean formation having a wellbore extending therein. The apparatus includes a radio frequency (RF) antenna configured to be positioned within the wellbore, a transmission line configured to be positioned in the wellbore and coupled to the RF antenna, and an RF source configured to be coupled to the transmission line. The apparatus also includes a balun configured to be coupled to the transmission line adjacent the RF antenna within the wellbore. The balun comprises a body defining a liquid chamber configured to receive a quantity of dielectric liquid therein.

Abstract: An apparatus is provided for heating a hydrocarbon resource in a subterranean formation having a wellbore extending therein. The apparatus includes a radio frequency (RF) source, an RE antenna configured to be positioned within the wellbore, and an RF transmission line configured to be positioned within the wellbore and couple the RE source to the RE antenna. The RE transmission line defines a liquid coolant circuit therethrough. The apparatus further includes a liquid coolant source configured to be coupled to the transmission line and to provide a liquid coolant through the liquid coolant circuit having an electrical parameter that is adjustable.

Abstract: A composite antenna reflector architecture for improving beam-to-beam isolation in a multi-spot illuminated reflector antenna employs a plurality of annular rings surrounding a central reflective dish and having respectively different controlled reflectivity profiles. The reflectivity-tailored reflector rings alter illumination taper and reduce selected sidelobe energy, and minimize degradation in coverage performance and gain slope in the radiation profile of the antenna. A respective ring employs a frequency selective surface laminate of layers containing different elements that resonate at different frequencies spectrally spaced to provide at least one composite frequency response characteristic.

Abstract: A composite antenna reflector architecture for improving beam-to-beam isolation in a multi-spot illuminated reflector antenna employs a plurality of annular rings surrounding a central reflective dish and having respectively different controlled reflectivity profiles. The reflectivity-tailored reflector rings alter illumination taper and reduce selected sidelobe energy, and minimize degradation in coverage performance and gain slope in the radiation profile of the antenna. A respective ring employs a frequency selective surface laminate of layers containing different elements that resonate at different frequencies spectrally spaced to provide at least one composite frequency response characteristic.

Abstract: A multiband, shaped ring focus antenna architecture employs only a single or common main reflector, that is shaped such that it can be shared by each of a pair of interchangeable, diversely shaped close proximity-coupled, subreflector-feed pairs designed for operation at respectively different spectral bands. The operational band of the antenna is changed by swapping out the subreflector-feed pairs. Placement of the shaped subreflector in close proximity to the feed horn reduces the diameter of the main shaped reflector relative to a conventional ring focus structure, so as to facilitate installation within a constrained space facility, such as a shipboard-mounted satellite communication system.