Provided herein are various enhanced antenna structures for radio frequency communications. In one example, an antenna includes a single-arm spiral antenna having an antenna element configured to couple to a radio frequency link at a central node of the spiral. A ground element is disposed proximate to the central node of the spiral and configured to couple to a ground reference for the radio frequency link.

The present invention generally relates to an electromagnetic field vector sensing receive antenna array system for installation and deployment on a structure. A multipolarized array of collocated antenna elements is used to provide calibrated amplitude and phase radiation patterns with monopole, dipole, and loop modes generated from crossed loops connected to a be informer. The invention has applications for installation and deployment on a tower, balloon, or satellite for radio frequency sensing and location of low-frequency galactic emissions. The novel receive antenna array system comprises a multipolarized vector sensor antenna array. The disclosed direction-finding vector sensor can be installed and deployed on a structure and can detect and locate radio frequency emissions from galactic sources. The key system components of the receive antenna array system consist of deployable antennas, receivers, signal processing computer, and communications link.

A reflector antenna, preferably a fixed mesh reflector antenna, and a process for manufacturing the reflector antenna, is disclosed that includes forming a support structure, placing a reflector surface on a mold, attaching the support structure to the reflector surface, measuring the geometry of the reflector surface, adjusting the surface geometry of the reflector if appropriate to obtain improved accuracy for the reflector surface, and fixedly connecting the support structure and the reflector surface. In an embodiment, the antenna reflector system includes a mesh reflector surface, a plurality of spline support elements, a plurality of splines connected to the reflector surface, and a plurality of adjustable spline supports attachable to the spline support elements and the splines, wherein the adjustable spline supports are adjustably repositionable with respect to the spline support elements, and also fixedly connectable to the spline support elements.

An antenna arrangement includes a conductive element configured to resonate at and above a chosen electromagnetic radiation frequency corresponding to a fundamental resonant mode. The conductive element is folded to make coupling areas intended to shift one or more of the resonant frequencies of the higher resonant modes. Each coupling area is defined related to the set of resonant frequencies according to which the antenna is supposed to work, and is formed by positioning parts of the conductive element facing each other. The location, along the conductive element, of the parts of that conductive element intended to form a given coupling area as well as the length of these parts and as the width of the gap between them when the coupling area is formed, are determined so as to provide a given increase or decrease of the resonant frequency of a given resonant mode of the conductive element.

An antenna arrangement includes a conductive element configured to resonate at and above a chosen electromagnetic radiation frequency corresponding to a fundamental resonant mode. The conductive element is folded to make coupling areas intended to shift one or more of the resonant frequencies of the higher resonant modes. Each coupling area is defined related to the set of resonant frequencies according to which the antenna is supposed to work, and is formed by positioning parts of the conductive element facing each other. The location, along the conductive element, of the parts of that conductive element intended to form a given coupling area as well as the length of these parts and as the width of the gap between them when the coupling area is formed, are determined so as to provide a given increase or decrease of the resonant frequency of a given resonant mode of the conductive element.

Disclosed are an antenna reflective net and an antenna reflective net mounting structure. Sliding slots are provided on side walls of the antenna reflective net mounting structure respectively. Protrusions of a base of the antenna reflective net slide into the sliding slots, and the size of the sliding slot is adapted to that of the protrusion. The protrusion is fixed in the sliding slot along a direction vertical to the sliding slot. A baffle block is provided at a distal end of the sliding slot. The baffle block restricts the protrusion from sliding along the direction of the distal end. Moreover, a limit part of an elastic pressing member of the antenna reflective net mounting structure restricts the protrusion from sliding along the direction of the entrance end of the sliding slot after the protrusion enters the sliding slot. Therefore, the antenna reflective net is easily mounted in the antenna reflective net mounting structure with high stability.

Provided is a glass panel unit that reduces the chances of an electric wire extended being disconnected. A glass panel unit includes a first panel, a second panel, a seal, a connecting void, and an electric wire. The first panel includes a first glass pane. The second panel includes a second glass pane and is arranged to face the second glass pane. The seal has a frame shape and hermetically bonds respective peripheral edge portions of the first panel and the second panel to create an internal space between the first panel and the second panel. The connecting void is provided for a portion, other than a portion facing the internal space, of at least one of the first panel or the second panel. The electric wire is extended from the internal space to the connecting void by passing through the seal.

Provided is a glass panel unit that reduces the chances of an electric wire extended being disconnected. A glass panel unit includes a first panel, a second panel, a seal, a connecting void, and an electric wire. The first panel includes a first glass pane. The second panel includes a second glass pane and is arranged to face the second glass pane. The seal has a frame shape and hermetically bonds respective peripheral edge portions of the first panel and the second panel to create an internal space between the first panel and the second panel. The connecting void is provided for a portion, other than a portion facing the internal space, of at least one of the first panel or the second panel. The electric wire is extended from the internal space to the connecting void by passing through the seal.

A logging tool includes a mandrel having an axis, a bobbin positioned about the circumference of the mandrel, and defining a first cross slot at a first slot angle and a second cross slot at a second slot angle opposite the first slot angle. The first and second cross slots intersect each other. The tool includes a first antenna in the first slot and including a first plurality of windings wrapped about the mandrel, a second antenna co-located with the first antenna and in the second slot, and an antenna shield secured to the tool mandrel and in each of the first and second slots. The first antenna is arranged in a first orientation and at a first winding angle. The second antenna is arranged in a second orientation and at a second winding angle.

Techniques for antenna positioning system having a drive element shared by multiple antennas for positioning about a positioning degree of freedom are described. In some examples, each antenna can be coupled with a rotating spindle, with each antenna spindle being coupled with the shared drive element. By driving a shared drive element, each of the antenna spindles in the system can be rotated via the associated coupling. In some examples, such a coupling may include link arms with an adjustable length to reduce backlash or to apply a preload to the system. In some examples, such a coupling may be configured to position multiple antennas over different orientation ranges in response to the drive element driving over an actuation range, which may include one antenna being idled or otherwise maintained at an orientation while another antenna is driven, or may include different antennas being driven according to different actuation ratios.