Abstract: The fuel quality sensor includes two rectangular parallepiped waveguides of equal dimensions stacked one atop the other and having a common ground. A thin wire extends through the intermediate wall(s) between the upper and lower waveguide cavities. An input connector is mounted on a sidewall of the upper waveguide, and an output connector is mounted on a sidewall of the lower waveguide cavity. A fluid conduit extends through the upper waveguide cavity adjacent the wire. A tunable microwave signal or wideband time domain pulse is applied to the input connector while fuel is flowing through the conduit. If the fuel flowing in the conduit is uncontaminated, the output signal at the second connector will show no change from the tunneling frequency, but if the fuel is contaminated, the change in the fuel's dielectric constant will result in a change in tunneling frequency and/or tan ? at the second connector.

Abstract: The fuel quality sensor includes two rectangular parallepiped waveguides of equal dimensions stacked one atop the other and having a common ground. A thin wire extends through the intermediate wall(s) between the upper and lower waveguide cavities. An input connector is mounted on a sidewall of the upper waveguide, and an output connector is mounted on a sidewall of the lower waveguide cavity. A fluid conduit extends through the upper waveguide cavity adjacent the wire. A tunable microwave signal or wideband time domain pulse is applied to the input connector while fuel is flowing through the conduit. If the fuel flowing in the conduit is uncontaminated, the output signal at the second connector will show no change from the tunneling frequency, but if the fuel is contaminated, the change in the fuel's dielectric constant will result in a change in tunneling frequency and/or tan ? at the second connector.

Abstract: The microstrip Fano resonator switch is a microstrip circuit having a varactor diode electrically connected between identical quarter-wavelength open stubs formed from two elongate planar strip elements disposed on a substrate having a permittivity of approximately 2.94 and a thickness of approximately 0.76 mm, the circuit forming a Fano resonator switch that provides approximately 50 dB of isolation.

Abstract: The microstrip circuits exhibiting electromagnetically induced transparency and Fano resonance include a microstrip transmission line and at least two identical parallel quarter-wavelength open stubs extending from the transmission line in close proximity so that mutual coupling between the electromagnetic fields at adjacent ends of the stubs induces Faro resonances and electromagnetically induced transparency (EIT). The circuits may be used for microwave buffers, or when a variable capacitance, such as a varactor, is inserted between the open ends of the stubs, the circuits may be used for active transmission phase control.

Abstract: The microstrip Fano resonator switch is a microstrip circuit having a varactor diode electrically connected between identical quarter-wavelength open stubs formed from two elongate planar strip elements disposed on a substrate having a permittivity of approximately 2.94 and a thickness of approximately 0.76 mm, the circuit forming a Fano resonator switch that provides approximately 50 dB of isolation.

Abstract: The microstrip circuits exhibiting electromagnetically induced transparency and Fano resonance include a microstrip transmission line and at least two identical parallel quarter-wavelength open stubs extending from the transmission line in close proximity so that mutual coupling between the electromagnetic fields at adjacent ends of the stubs induces Faro resonances and electromagnetically induced transparency (EIT). The circuits may be used for microwave buffers, or when a variable capacitance, such as a varactor, is inserted between the open ends of the stubs, the circuits may be used for active transmission phase control.