Abstract: A tuner (10) for a reverberation chamber is provided comprising a plurality of electrically conductive surfaces (12) attached to each other in a Z-fold configuration. Each lateral edge (15) of the tuner is contacted with a generally planar, laterally positioned substrate (16) which prevents lateral extension or medial compression of the Z-fold. Optionally, end substrates (18) are attached to each of the two leading edges (17). Also, a device minimizes electromagnetic radiation leakage along a shaft including: a bearing housing; a plurality of thrust bearings contacting the bearing housing and axially juxtaposed along the shaft so that at least two thrust bearings oppose each other; a radial bearing intermediate each thrust bearing; and a provision for adjustably moving the thrust bearings toward each other so as to compress the thrust bearings against the bearing housing.

Abstract: An EMI attenuation device comprising at least two substrates such that the spacing between these substrates is selected to maximize shielding performance at a particular frequency. The device further comprises additional substrates arranged at predetermined distances from the first two substrates to optimize shielding performance. A method also is provided for a multistep, attenuation of impinging EMI, wherein the method also enables see-through and/or hear-through monitoring. Salient features of the method include relatively positioning a plurality of electrically conductive substrates, each of a particular topology, so as to maximize attenuation of the EMI at particular frequencies.

Abstract: A telescopic high pressure sprinkler system is provided with a plurality of gaskets forming sliding seals between the piston and the outer conduit. Thus, the volume between the piston and the outer conduit forms a fluid chamber that is compressed as the piston is deployed so as to dampen the acceleration of sprinkler deployment. Furthermore, adjustable bleeder holes are provided to regulate the fluid chamber's compression while the gaskets provide a cushion when the piston comes to a stop. These bleeder holes also allow refilling of the piston fluid chamber.

Abstract: A device for suspending and moving a door leaf perpendicular and parallel to a wall. The device comprising a first set of rails extending in a direction perpendicular to the wall, a second set of rails extending in a direction parallel to the wall and an elongated member which extends both parallel to and perpendicular to the wall. The door leaf is slidably mounted on the first set of rails and the first set of rails is slidably mounted on the second set of rails. The door leaf includes a motor which operatively engages the elongated member to move the door leaf perpendicular to the wall and parallel to the wall to open and close an opening in the wall.

Abstract: An EMI attenuation device including at least two substrates such that the spacing between these substrates is selected to maximize shielding performance at a particular frequency. The device further includes additional substrates arranged at predetermined distances from the first two substrates to optimize shielding performance. A method also is provided for a multi-step, attenuation of impinging EMI, wherein the method also enables see-through and/or hear-through monitoring. Salient features of the method include relatively positioning a plurality of electrically conductive substrates, each of a particular topology, so as to maximize attenuation of the EMI at particular frequencies.

Abstract: A telescopic high pressure sprinkler system is provided with a plurality of gaskets forming sliding seals between the piston and the outer conduit. Thus, the volume between the piston and the outer conduit forms a fluid chamber that is compressed as the piston is deployed so as to dampen the acceleration of sprinkler deployment. Furthermore, bleeder holes are provided to regulate the fluid chamber's compression while the gaskets provide a cushion when the piston comes to a stop.

Abstract: A door assembly for an EMI shielded room includes a door structure defining an inner space parallel to the door faces. Plates are mounted in the space for movement toward and away from the door edges. Support and guide assemblies precisely regulate the plate movement. Either a pneumatic bladder, or a camming system, spaced inward from the door edges forces the plates to move outward from the door edges and parallel with the door plane. Return springs retract the plates when either the bladder is deflated, or the camming system is manipulated back to an at-rest position. The outer borders of the plates carry bumpers that force flexible contact members into engagement with the jamb and threshold of a doorway.

Abstract: A window wall for shielded enclosures is provided for use in a large opening in a shielded enclosure that preserves the shielding integrity of the shielded enclosure and that is easy to install. The window wall includes a frame having a frame perimeter received within a shielded enclosure window opening in electrical conductive engagement with the shielded enclosure. The frame includes a selected number of horizontal muntins and vertical mullions defining a plurality of clear window openings. A window unit frame is received in each clear window opening supported by and electrically connected to the frame. A pair of spaced apart radio frequency shielding continuous screens span each window opening and are supported by the window unit frame. Each screen is formed of electrically conductive mesh material and is mechanically and electrically connected with the window unit frame, thereby providing continuous electrical contact with the shielded enclosure.

Abstract: A shielding vent for an electromagnetic interference shielded enclosure having an electrically conducting wall shield includes a mounting plate or flange through which extends a vent pipe with an internal septum plate or divider extending axially along at least a portion of the inner length of the vent pipe. The mounting flange is secured to a wall of the shielded enclosure over an opening in the wall and to the wall shield to insure that the integrity of the shielding for the enclosure is maintained. With the mounting flange so mounted on the wall of the enclosure, the vent pipe extends through the opening in the wall of the enclosure and provides fluid communication between an internal region of the enclosure and a region external of the enclosure. The septum plate has a cross section in the shape of a cross so that at least a portion of the length of the cylindrically shaped vent pipe is subdivided into four parallel, axially extending equal fluid flow sections.

Abstract: A method of forming EMI shielded enclosures, an EMI shielded enclosure and EMI shield are provided. A sealer composition is applied onto a surface and is allowed to substantially dry cure into a uniform, seamless layer. An adhesive composition is applied to the dried sealer composition. Then, an electrically-conductive material, such as metallic sheet, such as copper sheeting, is attached to the dried sealer composition by the adhesive composition. Alternatively, a bonded sheet of dielectric material is applied to the adhesive composition. Then the metallic sheet is attached to the bonded sheet of dielectric material by an adhesive composition second layer.

Abstract: A window for electromagnetic interference shielded enclosures has a shielding screen system with two grids having dimensionally different mesh patterns to overcome optical interference and distraction resulting from the moire effect. The screens are supported in spaced, angularly offset positions on a continuous frame providing electrical continuity between the shielding system and the shielding layer of a surrounding wall.

Abstract: An improved RF shielding integrity monitoring system is provided for monitoring the shielding integrity of a shielded enclosure that accurately identifies degraded shielding effectiveness and leakage areas in the shielded enclosure. The RF shielding integrity monitoring system performs self-testing and self-diagnostic routines to assure proper system operation prior to monitoring of the shielded enclosure. The RF shielding integrity monitoring system includes a transmitter for transmitting predetermined transmitted by the shielded enclosure for receiving the signals; a receiver separated from the transmitted predetermined signals and for identifying the shielding effectiveness of the shielded enclosure; and a cable connected to the transmitter and the receiver for communicating signals between the transmitter and the reciever.

Abstract: A harmonic frequency selecting circuit is provided that simply and effectively provides a desired harmonic frequency output signal and that eliminates the need for frequency multiplier circuits. The harmonic frequency selecting circuit includes an oscillator circuit for generating a fundamental frequency signal and a plurality of harmonic frequency signals of the fundamental frequency signal. A phase modulator circuit is coupled to the oscillator circuit for selectively variably attenuating the generated fundamental and harmonic frequency signals. A bandpass filter circuit is coupled to the phase modulator circuit for selecting a predetermined harmonic frequency output signal.

Abstract: A panel system for EMI (electromagnetic interference) shielded enclosures includes panels having a framework, a substrate attached to the framework and a shielding layer overlying the substrate at the face of the panel and extending around the panel edges. Edge frame members of the framework are capable of floating or flexing to assure intimate contact between the shielding layers of adjacent panels when the panels are attached together to make a shielded enclosure. Seams between adjacent panels are provided with grooves for positively defining regions of contact and shielding the fasteners used to join the adjacent panels.

Abstract: A shield for the gap surrounding the door of an enclosure shielded against electromagnetic interference (EMI). The shield includes an elongated base having angularly related mounting and support flange portions adjustable by deformation to tailor the base to the gap. The mounting flange portion is adjustably clamped to the door face to hold the support flange portion in the gap. A finger assembly includes numerous fingers with first ends fixed to the base, second ends slidable on the support flange portion and contact portions engageable with the door frame.

Abstract: A window for an electromagnetic interference shielded enclosure includes a frame defining a window aperture. A pair of spaced apart, light transmitting, fluid impervious panels are supported by the frame and cover the aperture. In the region enclosed by the frame and the pair of panels, a quantity of light transmitting and electrically conductive fluid is captured. The fluid is electrically connected through the frame to the shield of an enclosure to provide an optically transparent window while maintaining the integrity of the shield.