Abstract: A dipole antenna includes a circuit board with a first side and a second side, at least one dipole disposed on the circuit board comprising an upper half and a lower half, a microstrip transmission line disposed on the circuit board coupled to at least one of the upper half and lower half of the at least one dipole, and a choke element disposed on the circuit board. The choke element and the lower half of the at least one dipole form an open slot trap with a high impedance point.

Abstract: A transmission line array is used for explosive/contraband detection using nuclear quadrupole resonance in which the array is driven in-phase with synchrony frequency-swept signals. Each of the balanced transmission lines is fed with a low power swept frequency source and stimulated emissions are picked out with a directional coupler. Location is provided using a cross grid array or a phase detector is used for each balanced line, with phase determining the distance to the sensed substance.

Abstract: The present invention provides a box-type housing for a multiplexer having a generally flat base plate, a circuit board disposed on the base plate, and at least one partition member arranged on top the circuit board to isolate components of the circuit board and to mechanically secure the circuit board to the base plate. The invention also provides a method of isolating components of a circuit board in a box-type housing for a multiplexer and a method of providing a ground connection to a base plate of a box-type housing for a multiplexer.

Abstract: Stimulated emissions due to nuclear quadropole resonance are detected utilizing a terminated balanced transmission line and a directional coupler for the detection of explosives, contraband, narcotics and the like that exist between the transmission lines, with either a stepped frequency generator utilized to scan between 100 KHz and 10 MHz, or wherein parallel fixed frequency sources are coupled to the transmission line, thereby to permit correlation with expected lines, with the frequency sources being low power so as to not create a safety hazard and so as not to interfere with radiation sensitive devices such as film or electronic circuits that are in the vicinity of the balanced transmission line.

Abstract: A spring boot for use with an antenna comprises a cylindrical main body having an annular flange at the lower end thereof, and an annular rim at the upper end thereof. The flange has a plurality of mounting holes therethrough. The interior of the spring boot is hollow and is configured to match the shape of the antenna spring. When installed, the spring boot is fitted over the spring, and seated on an antenna mount, encircling the spring. Fasteners are installed through the mounting holes on the flange to affix the spring boot to corresponding bores in the mount. A washer is positioned atop the rim and is fixed between the antenna core and the spring. This configuration effectively constrains the spring boot between the core and the mount, so as to provide added damping to the antenna spring.

Abstract: Rather than using balanced transmission lines the stimulated response due to nuclear quadrupole resonance can be detected using a single monopole, with multiple monopoles improving substance detection.

Abstract: A mobile multiband antenna has a frequency matching circuit located in a base mount housing for mounting the antenna to a carrier. A heat sink is located on a reverse side of the frequency matching circuit. One or more resistors in the frequency matching circuit are mounted to the heat sink to dissipate heat.

Abstract: A dipole antenna comprises a hollow dielectric whip, a coaxial center feed extending therethrough, and a pair of conductive dipole elements comprising an upper element and a lower element. The dipole antenna further comprises an upper element lead connecting the upper element to a first portion of the coaxial center feed at a feed point and a lower element lead connecting the lower element to a second portion of the coaxial center feed at the feed point. The dipole antenna further comprises a feed point strengthening means to mechanically strengthen the feed point against disconnection when the whip is impacted. Additionally, the dipole antenna may be a dual dipole antenna.

Abstract: Nuclear quadrupole resonance substance detection at a distance is provided by crossed or overlapping high frequency beams in which the frequency of one of the beams is offset with respect to the frequency of the other beam by an amount equal to the resonant frequency of the non-linear material to be detected. The presence of energy at the offset frequency within the overlapping beams pumps any non-linear material within the overlapping beams to cause stimulated emission which is detected, in one embodiment, utilizing a network analyzer, along with correlation of the detected stimulated emission signature with a library of signatures for predetermined substances.

Abstract: A whip antenna assembly having an electrically conductive coupler, opposing stacks of discrete blades of varying heights nested together, and a flexible lift cable having a length greater than the first and second opposing stacks. Where the conductive blades are loosely held together for slidable movement relative to each other. The whip antenna assembly can be lifted by the distal end of the flexible lift cable without interfering with the opposing stacks, while remaining flexible enough to bend.

Abstract: A dipole antenna includes a circuit board with a first side and a second side, at least one dipole disposed on the circuit board comprising an upper half and a lower half, a microstrip transmission line disposed on the circuit board coupled to at least one of the upper half and lower half of the at least one dipole, and a choke element disposed on the circuit board. The choke element and the lower half of the at least one dipole form an open slot trap with a high impedance point.

Abstract: A marine multiband antenna array includes a nearly virtual bow tie UHF antenna and a connected VHF/FM antenna that together function as an AM antenna. A diplexer separates the AM/FM radio signals from the UHF/VHF television signals.

Abstract: A multiplexer circuit for CB, AM/FM, and television splits the radio and television signals, adding impedance to the split lines, and providing an amplifier upstream of the split.

Abstract: A marine multiband antenna array includes a nearly virtual bowtie UHF antenna and a connected VHF/FM antenna that together function as an AM antenna. A diplexer separates the AM/FM radio signals from the UHF/VHF television signals.

Abstract: A field antenna comprises an antenna assembly and an optional mast assembly. The antenna assembly can comprise two antenna portions coupled to a feedcone assembly as a single foldable unit. The mast assembly can comprise a unitary telescoping mast. The field antenna can be part of an antenna kit that can be disassembled and packed in a transit bag for storage and transport. The antenna assembly can be used as a field antenna alone, or can be selectively mounted to the mast assembly or a vehicle.

Abstract: An antenna comprises a lower section, an upper section, and a junction connecting them to each other. The junction has a key and a keyway to permit joining them only one way. In one embodiment, a whip assembly is joined to a mount assembly by a keyed junction.

Abstract: An antenna assembly has a lower break assembly and an upper break assembly. Both have a center fed transmission line within a conductive tube, and both are mutually connectable for connecting the transmission lines to each other at a junction. When connected, the lower break assembly and upper break assembly form one pole of a center-fed dipole radiator without significant signal loss through the junction.

Abstract: A mobile antenna includes a center-fed, broadband, dipole radiator, and a coupler assembly for mounting the dipole radiator to a mount. A power matching circuit is connected between the dipole radiator and the coupler assembly to maintain an effective balance of current distribution and impedance in conductive elements of the antenna.

Abstract: A broadband antenna comprises an upper section with an open sleeve dipole radiator to receive and/or transmit signals in a high frequency band.

Abstract: A multiband antenna system includes a multiband antenna adapted to receive signals in a given frequency range, such as CB, and a trap to isolate signals in the tire pressure monitoring frequency ranges so that when it is mounted to the exterior of a vehicle in conventional manner, it will optimally receive signals sent from tire pressure monitors in the wheels. The system includes a multiplexer circuit that connects to tire pressure monitoring apparatus and isolates the tire pressure monitoring frequencies from CB frequencies. The antenna and multiplexer circuits are capable of simultaneously handling other frequencies as well such as AM/FM.