Abstract: In ultra-wideband or impulse radio terahertz wireless communication, the electromagnetic signal may experience group delay dispersion (GDD). Without correction, this can degrade the achievable data transmission rate. An apparatus comprising a stratified structure having a front portion and a back portion is disclosed. The structure comprises a plurality of adjacent layers of differing refractive indices, wherein each layer has a refractive index different from an immediately adjacent layer. The structure further includes a backing layer at the back portion. The structure defines a GDD, which can be adjusted, and the structure is configured to introduce the GDD to an incident electromagnetic signal and thereby produce a dispersion-compensated electromagnetic signal when the incident signal is reflected by the structure. The GDD of the structure is configured to substantially cancel out the dispersive effects experienced by the electromagnetic signal in the signal path.

Abstract: In ultra-wideband or impulse radio terahertz wireless communication, the atmosphere reshapes terahertz pulses via group delay dispersion (GDD). Without correction, this can degrade the achievable data transmission rate. An apparatus comprising a stratified structure having a front end and a back end is disclosed. The structure comprises a plurality of adjacent layers of differing refractive indices, wherein each layer has a refractive index different from an immediately adjacent layer. The structure further includes a backing layer at the back end. The structure defines a GDD, which can be adjusted, and the structure is configured to introduce the GDD to a received terahertz signal and thereby produce a compensated terahertz signal when the received terahertz signal is reflected by the structure. The GDD of the structure is configured to substantially cancel out the GDD effects caused by the atmosphere on the terahertz signal.

Abstract: Embodiments of an aerobic septic system health monitor, and a method of its use, incorporate a microcontroller, with associated software, in communication with an aerobic septic system (electro-mechanical) controller that, in turn, is connected to at least one aerobic septic system component and component sensor. By using the microcontroller and software, highly specific monitoring and feedback is available to a user. This approach also offers a clear and easily accessible interface between the user and the aerobic septic system, whereas no such interface exists on prior art systems. The monitor also offers multiple redundancy to address system failures, unlike prior art. Finally, it enables several forms of preventative maintenance that simply don't exist in prior art systems. In some embodiments, the monitor may serve as the aerobic septic system controller, either overriding or supplementing the installed controller or replacing it.

Abstract: A geometrically modifiable resonator is comprised of a resonator disposed on a substrate, and a means for geometrically modifying the resonator. The geometrically modifiable resonator can achieve active optical and/or electronic control of the frequency response in metamaterials and/or frequency selective surfaces, potentially with sub-picosecond response times. Additionally, the methods taught here can be applied to discrete geometrically modifiable circuit components such as inductors and capacitors. Principally, controlled conductivity regions, using either reversible photodoping or voltage induced depletion activation, are used to modify the geometries of circuit components, thus allowing frequency tuning of resonators without otherwise affecting the bulk substrate electrical properties. The concept is valid over any frequency range in which metamaterials are designed to operate.

Abstract: Metamaterial structures are taught which provide for the modulation of terahertz frequency signals. Each element within an array of metamaterial (MM) elements comprises multiple loops and at least one gap. The MM elements may comprise resonators with conductive loops and insulated gaps, or the inverse in which insulated loops are present with conductive gaps; each providing useful transmissive control properties. The metamaterial elements are fabricated on a semiconducting substrate configured with a means of enhancing or depleting electrons from near the gaps of the MM elements. An on to off transmissivity ratio of about 0.5 is achieved with this approach. Embodiments are described in which the MM elements incorporated within a Quantum Cascade Laser (QCL) to provide surface emitting (SE) properties.

Abstract: Metamaterial structures are taught which provide for the modulation of terahertz frequency signals. Each element within an array of metamaterial (MM) elements comprises multiple loops and at least one gap. The MM elements may comprise resonators with conductive loops and insulated gaps, or the inverse in which insulated loops are present with conductive gaps; each providing useful transmissive control properties. The metamaterial elements are fabricated on a semiconducting substrate configured with a means of enhancing or depleting electrons from near the gaps of the MM elements. An on to off transmissivity ratio of about 0.5 is achieved with this approach. Embodiments are described in which the MM elements incorporated within a Quantum Cascade Laser (QCL) to provide surface emitting (SE) properties.

Abstract: A geometrically modifiable resonator is comprised of a resonator disposed on a substrate, and a means for geometrically modifying the resonator. The geometrically modifiable resonator can achieve active optical and/or electronic control of the frequency response in metamaterials and/or frequency selective surfaces, potentially with sub-picosecond response times. Additionally, the methods taught here can be applied to discrete geometrically modifiable circuit components such as inductors and capacitors. Principally, controlled conductivity regions, using either reversible photodoping or voltage induced depletion activation, are used to modify the geometries of circuit components, thus allowing frequency tuning of resonators without otherwise affecting the bulk substrate electrical properties. The concept is valid over any frequency range in which metamaterials are designed to operate.

Abstract: Disclosed are schemes for selecting an interexchange telephone call carrier, selecting a route to the selected carrier, and establishing a call path on the selected route to the selected carrier in a multicarrier environment. Call path establishment from an end office at which a call is originating to the carrier's office is accomplished via a multifrequency signaling scheme. If the call is an international call or the route is an indirect route to a carrier via an access tandem, following seizure of a trunk the end office outpulses thereon a first sequence of information that characterizes the subsequent route that the call should take, including identity of the interexchange or international carrier. After receiving a wink responsive to the first sequence, the end office outpulses a second sequence. If the call is a domestic call routed directly to a carrier, following seizure of the trunk the end office begins outpulsing with the second sequence.