G. Dickey Arndt - Friendswood TX Phong H. Ngo - Friendswood TX Henry A. Chen - Houston TX Chau T. Phan - Houston TX Brian A. Bourgeois - Houston TX John Dusl - Houston TX Brent W. Hill - San Diego CA
Assignee:
United States of America as represented by the Administrator of the National Aeronautics and Space Administration - Washington DC
International Classification:
G01S 302
US Classification:
342465, 342442, 342463
Abstract:
System and methods are disclosed for passively determining the location of a moveable transmitter utilizing a pair of phase shifts at a receiver for extracting a direction vector from a receiver to the transmitter. In a preferred embodiment, a phase difference between the transmitter and receiver is extracted utilizing a noncoherent demodulator in the receiver. The receiver includes an antenna array with three antenna elements, which preferably are patch antenna elements spaced apart by one-half wavelength. Three receiver channels are preferably utilized for simultaneously processing the received signal from each of the three antenna elements. Multipath transmission paths for each of the three receiver channels are indexed so that comparisons of the same multipath component are made for each of the three receiver channels. The phase difference for each received signal is determined by comparing only the magnitudes of received and stored modulation signals to determine a winning modulation symbol.
G. Dickey Arndt - Friendswood TX, US Phong H. Ngo - Friendswood TX, US Henry A. Chen - Houston TX, US Chau T. Phan - Houston TX, US Brian A. Bourgeois - Houston TX, US John Dusl - Houston TX, US Brent W. Hill - San Diego CA, US
Assignee:
The United States of America as represented by the National Aeronautics and Space Administration - Washington DC
International Classification:
G01S001/08 G01S005/04 H01Q001/00
US Classification:
342465, 342370, 342442, 342463
Abstract:
System and methods are disclosed for passively determining the location of a moveable transmitter utilizing a pair of phase shifts at a receiver for extracting a direction vector from a receiver to the transmitter. In a preferred embodiment, a phase difference between the transmitter and receiver is extracted utilizing a noncoherent demodulator in the receiver. The receiver includes antenna array with three antenna elements, which preferably are patch antenna elements aced apart by one-half wavelength. Three receiver channels are preferably utilized for simultaneously processing the received signal from each of the three antenna elements. Multipath transmission paths for each of the three receiver channels are indexed so that comparisons of the same multipath component are made for each of the three receiver channels. The phase difference for each received signal is determined by comparing only the magnitudes of received and stored modulation signals to determine a winning modulation symbol.
Ultrawideband Asynchronous Tracking System And Method
G. Dickey Arndt - Friendswood TX, US Phong H. Ngo - Friendswood TX, US Chau T. Phan - Sugar Land TX, US Julia A. Gross - Houston TX, US Jianjun Ni - Pearland TX, US John Dusl - Houston TX, US
Assignee:
The United States of America as represented by the Administrator of the National Aeronautics and Space Administration - Washington DC
International Classification:
H04B 1/00
US Classification:
375130, 375267, 342126, 342133, 342147, 4554561
Abstract:
A passive tracking system is provided with a plurality of ultrawideband (UWB) receivers that is asynchronous with respect to a UWB transmitter. A geometry of the tracking system may utilize a plurality of clusters with each cluster comprising a plurality of antennas. Time Difference of Arrival (TDOA) may be determined for the antennas in each cluster and utilized to determine Angle of Arrival (AOA) based on a far field assumption regarding the geometry. Parallel software communication sockets may be established with each of the plurality of UWB receivers. Transfer of waveform data may be processed by alternately receiving packets of waveform data from each UWB receiver. Cross Correlation Peak Detection (CCPD) is utilized to estimate TDOA information to reduce errors in a noisy, multipath environment.
Methods And Apparatus For Microwave Tissue Welding For Wound Closure
G. Dickey Arndt - Friendswood TX, US Phong H. Ngo - Friendswood TX, US Chau T. Phan - Sugar Land TX, US Diane L. Byerly - Seabrook TX, US John R. Dusl - Houston TX, US Marguerite A. Sognier - Houston TX, US James R. Carl - Houston TX, US
Assignee:
The United States of America as represented by the Administrator of the National Aeronautics and Space Administration - Washington DC
International Classification:
A61B 18/14
US Classification:
606 33, 606 49, 606 41, 607101
Abstract:
Methods and apparatus for joining biological tissue together are provided. In at least one specific embodiment, a method for joining biological tissue together can include applying a biological solder on a wound. A barrier layer can be disposed on the biological solder. An antenna can be located in proximate spatial relationship to the barrier layer. An impedance of the antenna can be matched to an impedance of the wound. Microwaves from a signal generator can be transmitted through the antenna to weld two or more biological tissue pieces of the wound together. A power of the microwaves can be adjusted by a control circuit disposed between the antenna and the signal generator. The heating profile within the tissue may be adjusted and controlled by the placement of metallic microspheres in or around the wound.
G. Arndt - Friendswood TX, US Phong Ngo - Friendswood TX, US James Carl - Houston TX, US Kent Byerly - Seabrook TX, US John Dusl - Houston TX, US
International Classification:
G01R027/04 G01R027/32
US Classification:
324/639000
Abstract:
Transceiver and methods are disclosed that are especially suitable for detecting metallic materials, such as metallic mines, within an environment. The transceiver includes a digital waveform generator used to transmit a signal into the environment and a receiver that produces a digital received signal. A tracking module preferably compares an in-phase and quadrature transmitted signal with an in-phase and quadrature received signal to produce a spectral transfer function of the magnetic transceiver over a selected range of frequencies. The transceiver initially preferably creates a reference transfer function which is then stored in a memory. Subsequently measured transfer functions will vary depending on the presence of metal in the environment which was not in the environment when the reference transfer function was determined. The system may be utilized in the presence of other antennas, metal, and electronics which may comprise a plastic mine detector for detecting plastic mines. Despite the additional antennas and other metallic materials that may be in the environment due to the plastic mine detector, the magnetic transceiver remains highly sensitive to metallic material which may be located in various portions of the environment and which may be detected by sweeping the detector over ground that may contain metals or mines.
Method And Device For Treating Caries Using Locally Delivered Microwave Energy
- Bethesda MD, US Marguerite A. Sognier - Houston TX, US George D. Arndt - Friendswood TX, US Diane L. Byerly - Seabrook TX, US John Dusl - Houston TX, US
International Classification:
A61C 19/06 A61C 17/02 A61N 5/02
Abstract:
A method and a device for treating dental caries using microwave energy applied directly to teeth at frequencies that are lethal to the bacteria in caries, without being destructive to tooth tissues. The method and a device will have a significant economic and health impact, leading to a reduction in traditional surgical interventions, as well by improving access to care for those with health disparities.