Abstract: A method to implement circuits and circuit elements having one or more ports may include digitizing, using analog-to-digital converters, continuous-time input signals received from one or more ports of a circuit to form discrete-time input signals. At a digital signal processor, the discrete-time input signals are received and the discrete-time input signals are processed to calculate a desired discrete-time output signals. Using digital-to-analog converters, the calculated desired discrete-time output signal are calculated to form outputs of continuous-time output signals at the one or more ports of the circuit. The continuous-time output signals are output to the same one or more ports that receive the continuous-time input signals; and producing, thereby, a desired relationship between the continuous-time output signals and the continuous-time input signals at the one or more ports.

Abstract: A metamaterial simultaneously exhibiting a relative effective permeability and a relative effective permittivity below unity over a wide bandwidth, including: one of a two-dimensional and a three-dimensional arrangement of unit cells, wherein each of the unit cells has a magnetic dipole moment and an electric dipole moment that are dependent upon one or more of an incident magnetic field and an incident electric field; and a coupling mechanism operable for coupling one or more of the incident magnetic field and the incident electric field to one or more devices. Optionally, the coupling mechanism includes one or more of a split ring and a pair of parallel plates coupled by one of a rod and a wire. The one or more devices are non-Foster elements.

Abstract: A method to implement circuits and circuit elements having one or more ports may include digitizing, using analog-to-digital converters, continuous-time input signals received from one or more ports of a circuit to form discrete-time input signals. At a digital signal processor, the discrete-time input signals are received and the discrete-time input signals are processed to calculate a desired discrete-time output signals. Using digital-to-analog converters, the calculated desired discrete-time output signal are calculated to form outputs of continuous-time output signals at the one or more ports of the circuit. The continuous-time output signals are output to the same one or more ports that receive the continuous-time input signals; and producing, thereby, a desired relationship between the continuous-time output signals and the continuous-time input signals at the one or more ports.

Abstract: A metamaterial simultaneously exhibiting a relative effective permeability and a relative effective permittivity below unity over a wide bandwidth, including: one of a two-dimensional and a three-dimensional arrangement of unit cells, wherein each of the unit cells has a magnetic dipole moment and an electric dipole moment that are dependent upon one or more of an incident magnetic field and an incident electric field; and a coupling mechanism operable for coupling one or more of the incident magnetic field and the incident electric field to one or more devices. Optionally, the coupling mechanism includes one or more of a split ring and a pair of parallel plates coupled by one of a rod and a wire. The one or more devices are non-Foster elements.

Abstract: A system for providing a temperature compensated measurement indicative of the height of a fluid in a vessel includes an acoustic waveguide in fluid communication with the vessel. A reference target is positioned within the waveguide. Ultrasonic signals are produced in the fluid and a timer measures a first transit time representative of the time for the ultrasonic signals to travel to and from the target and a second transit time representative of the time for the ultrasonic signals to travel to and from the surface of a fluid in the waveguide. A circuit calculates the height of the fluid in the waveguide from the first and second transit times. Another circuit determines the density of the fluid in the waveguide from the first transit time and normalizes the calculated height of the fluid based on the density of the fluid such that the normalized height is indicative of the height of the fluid in the vessel.

Abstract: A magnetic displacement transducer system for measuring the movement of a member includes an elongated permanent magnet which is mechanically coupled to the member so that the magnet moves parallel to its axis. A magnet-position sensor assembly, which includes at least one magnetometer having an elongated ferromagnetic core with a coil wrapped around it, is positioned adjacent the magnet so that the axis of the core and coil intersects the axis of the magnet at right angles. A pair of wires carry a sinusoidal excitation current to the assembly, convey the second harmonic from the assembly, and deliver a DC biasing current to the assembly in order to null the component of the permanent magnet's field that is perpendicular to the axis of the magnet. The value of the DC biasing current is measured to obtain the displacement of the member.