Abstract: A radio frequency (RF) filter includes an input port configured to receive a signal, an output port configured to output a signal, and a tuning probe configured to be movable within a tuning probe port to adjust filter characteristics. The tuning probe port is configured to receive the tuning probe therein, and a locking mechanism is configured to lock the tuning probe in the tuning probe port at a desired depth and further configured to prevent movement of the tuning probe in the tuning probe port when the locking mechanism is in a locked configuration.

Abstract: A circularly polarized patch antenna uses a square quarter-wavelength conductive plate, spaced away from a slightly larger backing conductor. Excitation uses a coaxial feed stem pair, whereof respective inner conductors join the patch at orthogonal locations on a reference circle, and outer conductors intrude past points of joining to the backing conductor to establish gaps that interact with patch and backing conductor size and spacing to jointly establish terminal impedance. A parasitic element in the propagation path broadens bandwidth, while a frame behind serves to define a cavity reflector. A power divider behind the frame converts a single applied broadcast signal into two equal signals with orthogonal phase, which signals are delivered to the feed stems with equal-length coaxial lines.

Abstract: An antenna radiator is provided. The radiator includes four elements, each including a node, a first ring connected to the node, and a second ring connected to the node and disposed inside of and coplanar with the first ring. The first ring includes a first plurality of segments, and the second ring includes a second plurality of segments.

Abstract: A method and apparatus for dry testing non-conductive containers for carrying people are disclosed. Two conductive materials placed on opposite sides of a material being tested. High voltage is applied to one of the conductive materials while a ground lead is attached to the other conductive material. Electric current is measured from the grounded conductive material to identify any breakdown of the dielectric properties of the material being tested.

Abstract: A method and apparatus for dry testing non-conductive containers for carrying people are disclosed. Two conductive materials placed on opposite sides of a material being tested. High voltage is applied to one of the conductive materials while a ground lead is attached to the other conductive material. Electric current is measured from the grounded conductive material to identify any breakdown of the dielectric properties of the material being tested.