Abstract: A system and method is provided for improving the operating range for UWB communication systems by increasing the margin between true correlation peaks and false correlation peaks in a received UWB signal. A received signal is first correlated with a UWB kernel before being correlated with the PRN code. The UWB kernel is a very short UWB pulse having the same pulse shape as the UWB signal pulses. By pre-correlating the received signal with the UWB kernel at least once prior to correlating with the PRN code, the margin between true correlation peaks and false correlation peaks is substantially improved.

Abstract: A multi-band receiver for use with satellite ranging systems is provided. The receiver has a simplified architecture in which input signals of various frequencies are multiplexed together to form a single composite analog signal. In accordance with one embodiment of the invention, this composite signal only requires a single RF circuit for down conversion to an intermediate frequency. The composite, downconverted signal is sampled, and the digitized samples are demultiplexed to form digital counterparts of the original signals from each frequency band. An embodiment for use with elements of a phased array antenna is also provided.

Abstract: An antenna that is suitable for transmission and reception of UWB signals is provided. The antenna includes a pair of conducting spheres separated by an air gap. A first conducting sphere is connected to a first conductor of a transmission line and a second conducting sphere is connected to a second conductor of the transmission line. The dual sphere antenna provides consistent performance in the azimuth plane and across the frequency band for UWB applications.

Abstract: A system and method is provided for improving the operating range for UWB communication systems by increasing the margin between true correlation peaks and false correlation peaks in a received UWB signal. A received signal is first correlated with a UWB kernel before being correlated with the PRN code. The UWB kernel is a very short UWB pulse having the same pulse shape as the UWB signal pulses. By pre-correlating the received signal with the UWB kernel at least once prior to correlating with the PRN code, the margin between true correlation peaks and false correlation peaks is substantially improved.

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.

Abstract: A multi-band receiver for use with satellite ranging systems is provided. The receiver has a simplified architecture in which input signals of various frequencies are multiplexed together to form a single composite analog signal. In accordance with one embodiment of the invention, this composite signal only requires a single RF circuit for down conversion to an intermediate frequency. The composite, downconverted signal is sampled, and the digitized samples are demultiplexed to form digital counterparts of the original signals from each frequency band. An embodiment for use with elements of a phased array antenna is also provided.

Abstract: A GPS-inertial system that is suited to new installations as well as the retrofitting of GPS receivers includes inertial sensors that are incorporated into the housing of the GPS antenna. The outputs of the inertial sensors are modulated onto a radio frequency carrier that has the same frequency as the GPS carrier, using the same data modulation arrangement as that used by the GPS system. The inertial measurements are thus sent to the receiver on the same cable as the RF signals from the antenna, and the receiver recovers the data from the sensor signals with the same arrangement that is used for data recovery from GPS position signals. Consequently, software modifications of existing GPS receivers can provide position and velocity estimates generated from the outputs of the inertial sensors.

Abstract: A planar, controlled radiation pattern array antenna using spiral slot antenna arrays is disclosed. The CRPA antenna includes a nonconductive planar substrate with a plurality of transmission lines disposed on one surface. A conductive layer on the other surface of the substrate includes a plurality of slotted openings that form spiral slot array antennas such that each spiral slot array antenna opposed to a transmission line on the opposite side of the substrate.

Abstract: A slot-array antenna includes a nonconductive substantially planar substrate and a transmission line disposed on a rear substrate surface where one end of the transmission line is connected to an amplifier, a connector, or an impedance load. A conductive layer on the front substrate surface includes a plurality of slotted openings arrayed about an antenna axis. A surface-wave suppression region encloses the array of slotted openings and a plurality of peripheral openings are disposed between the surface-wave suppression region and the peripheral edge of the antenna.

Abstract: A planar, phased-array antenna including a nonconductive substantially planar substrate and a transmission line disposed on one surface is disclosed, a segment of the transmission line forming an arc of radius R centered on the antenna axis. A conductive layer on the other antenna surface includes two or more slotted openings, each slotted opening having one end located within a distance R of the antenna axis, such that, when an electromagnetic signal is fed into one end of the transmission line, electromagnetic energy is sequentially coupled into the slotted openings, and a circularly-polarized signal is radiated from the antenna substantially in the direction of the antenna axis. An amplifier or a connector may be electrically connected to one or both ends of the transmission line, or one end of the transmission line may be terminated in an impedance load to form a leaky-wave antenna. The slotted openings may comprise either or both straight and curved segments, and may be of the same or unequal lengths.

Abstract: A planar, phased-array antenna including a nonconductive substantially planar substrate and a transmission line disposed on one surface is disclosed, a segment of the transmission line forming an arc of radius R centered on the antenna axis. A conductive layer on the other antenna surface includes two or more slotted openings, each slotted opening having one end located within a distance R of the antenna axis, such that, when an electromagnetic signal is fed into one end of the transmission line, electromagnetic energy is sequentially coupled into the slotted openings, and a circularly-polarized signal is radiated from the antenna substantially in the direction of the antenna axis. An amplifier or a connector may be electrically connected to one or both ends of the transmission line, or one end of the transmission line may be terminated in an impedance load to form a leaky-wave antenna. The slotted openings may comprise either or both straight and curved segments, and may be of the same or unequal lengths.

Abstract: A slot-array antenna includes a nonconductive substantially planar substrate and a transmission line disposed on a rear substrate surface where one end of the transmission line is connected to an amplifier, a connector, or an impedance load. A conductive layer on the front substrate surface includes a plurality of slotted openings arrayed about an antenna axis. A surface-wave suppression region encloses the array of slotted openings and a plurality of peripheral openings are disposed between the surface-wave suppression region and the peripheral edge of the antenna.

Abstract: Apparatus using a global positioning system (GPS) for finding out the attitude of a rotating space vehicle employs first and second antennae mounted opposite from each other on a circumference of the body of the rotating space vehicle. The antennae receive GPS satellite signals in their channels. A control and tracking loop processor monitors the signal strength in each channel. Phase errors produced by phase discriminators of each channel arc combined to produce a spin signature which is used to calculate the vehicle spin rate and vehicle attitude.

Abstract: A GPS receiver embodying the invention includes a first channel that preferentially processes line-of-sight signals and a second channel that preferentially processes multipath signals. It then compares the results to determine if the multipath has degraded the results of the processing of the line-of-sight signals.