Abstract:
Disclosed herein are systems and methods for using high phase noise oscillators in Doppler radar systems. In some embodiments, a transmit pulse is sampled corresponding with a transmission time, and a phase noise correction factor is developed based on the sample transmit pulse and corresponding with the transmission time. A return echo is received that corresponds with the transmission time of the transmit pulse, and the return echo is modified based on the phase noise correction factor derived from the corresponding transmit pulse. In some embodiments, the transmit pulse can be generated from a magnetron or other high power oscillator having high phase noise. In some embodiments, the modified return echo is processed to differentiate clutter by resolving a Doppler shift.
Abstract:
An RF circuit which may be for example a high pass filter, low pass filter, phase shifter, bandpass filter, termination network, bias network, or series or parallel resonance circuit includes at least one strip conductor coiled about a region and an outer or ring strip conductor disposed about a periphery of the at least one coiled strip conductor and coupled to said at least one coiled strip conductor through a dielectric. Parasitic capacitance between the coiled conductor and outer or ring conductor provide capacitor elements for the circuit.
Abstract:
A field emission display having a plurality of pixels is disclosed wherein each pixel includes a cathode with a plurality of field emitters and corresponding gate electrodes to emit electrons, an anode distally disposed with respect to the cathode, the anode and the cathode capable of having a voltage difference greater than 6000 volts, and a focus grid disposed between the anode and the cathode, the focus grid having an aperture and disposed in proximity with the cathode to focus electrons from the plurality of field emitters of the cathode toward the anode. With such an arrangement, a field emission display is provided having greater brightness and efficiency.
Abstract:
A field emission display having a plurality of cathodes; a cathodoluminescent anode; a plurality of control electrodes for controlling the flow of electrons between the cathodes and the anode; a focus grid comprising an apertured, conductive sheet; and a dielectric material is disposed on the focus grid between the conductive sheet and the control electrodes. With such an arrangement, the dielectric material prevents the focus grid from electrically contacting the control electrodes. Further, it has been discovered that high angle electrons emitted by each pixel are inhibited from passing through the focus grid associated with an adjacent pixel to reduce cross-talk. It is believed that surface charge forms on the dielectric material and acts as an additional focusing structure that reduces the number of high angle electrons emitted from one pixel from passing through an adjacent focus grid aperture resulting in a “cross-talk” image on the cathode. In another embodiment, the dielectric layer is disposed between, and in contact with, the focus grid and the cathode structure to provide an integral structure which prevents contact between the surface of the focus grid and the gate electrodes. A method is provided for forming a grid for a field emission display. The method includes the step of spraying a dielectric material towards a surface of the grid while a vacuum draws the spray from the surface through apertures in the grid.