Abstract: A system may comprise a cathode, a target, one or more switches, and a conductive element. The cathode may be configured and arranged to generate an electron beam, and the target may be configured and arranged to emit radiation when electrons in the electron beam impact the target after being accelerated by an energy source. The one or more switches may be configured and arranged to apply either a first voltage or a second voltage from a power supply between the cathode and the target. The conductive element may be disposed between the cathode and the target so as to inhibit the electron beam generated by the cathode from reaching the target when a signal is applied to the conductive element.

Abstract: An antenna is provided for acquiring RF signals from various satellite ranging systems including GPS, GLONASS, GALILEO and OmniSTAR®. The antenna configuration includes a radiating structure of multi-arm spiral slots terminated with fractal loops. A leaky wave microstrip spiral feed network is used to excite the radiating structure of the antenna. The fixed beam phased array of aperture coupled slots is optimized to receive a right hand polarized signal. The proposed antenna is made out of a single PCB board. The antenna has a very uniform phase and amplitude pattern in the azimuth plane from 1.15 to 1.65 GHz, therefore providing consistent performance at GPS, GLONASS, GALILEO and OmniSTAR® frequencies. The antenna also has a common phase center at the various frequencies from 1175 MHz to 1610 MHz and substantially the same radiation pattern and axial ratio characteristics.

Abstract: An antenna is provided for acquiring RF signals from various satellite ranging systems including GPS, GLONASS, GALILEO and OmniSTAR®. The antenna configuration includes a radiating structure of multi-arm spiral slots terminated with fractal loops. A leaky wave microstrip spiral feed network is used to excite the radiating structure of the antenna. The fixed beam phased array of aperture coupled slots is optimized to receive a right hand polarized signal. The proposed antenna is made out of a single PCB board. The antenna has a very uniform phase and amplitude pattern in the azimuth plane from 1.15 to 1.65 GHz, therefore providing consistent performance at GPS, GLONASS, GALILEO and OmniSTAR® frequencies. The antenna also has a common phase center at the various frequencies from 1175 MHz to 1610 MHz and substantially the same radiation pattern and axial ratio characteristics.