University of California

California Institute of Technology

United States of America As Represented by the Administrator of Nasa

Adrian Tang

Mau-Chung Frank Chang

Nacer Chahat

Goutam Chattopadhyay

Yanghyo Kim

Emmanuel Decrossas

Erich T Schlecht

Rulin Huang

Brian J Drouin

We have demonstrated that the bandwidth millimeter wavelengths offer can be leveraged to deeply spread a low-data rate signal below the thermal floor of the environment (sub-thermal) by lowered transmit power combined with free space losses, while still being successfully received through a novel dispreading structure which does not rely on pre-detection to extract timing information. The demonstrated data link ensures that it cannot be detected beyond a designed range from the transmitter, while still providing reliable communication. A demonstration chipset of this sub-thermal concept was implemented in a 28 nm CMOS technology and when combined with an InP receiver was shown to decode signals up to 30 dB below the thermal noise floor by spreading a 9600 bps signal over 1 GHz of RF bandwidth from 93 to 94 GHz using a 64 bit spreading code. The transmitter for this chipset consumed 62 mW while the receiver consumed 281 mw.

Sub-thermal spread spectrum data-link

A system, apparatus and method are disclosed for communicating between a short range wireless (WLAN) user device, such as a wearable, phone, or tablet, with a base station. Traditional low power communication (e.g., WLAN, WiFi, Bluetooth, cellular links, etc.) involve an inefficient amplification process of a signal from the WLAN user to the base station, whereby significant power must be expended in the WLAN user device making it unsuitable in many applications. A reflector link paradigm is disclosed in which the user device communicates by modulating the extent of signal reflected back to the base station. An enhanced reflector is also disclosed which overcomes adverse effects of ambient reflections.

Microwave reflector link, and CDMA-spread spectrum reflector apparatus for reduction of unmodulated ambient blockers in reflected data links

A coupler for coupling electromagnetic radiation into a cavity, including a metal layer having a reflective surface and forming a ground plane; and one or more waveguides for gigahertz or terahertz electromagnetic radiation embedded in the metal layer. The waveguides each include two openings in the metal layer exposing a dielectric underneath; and a section of the metal layer between the two openings. A plurality of holes in the metal layer are disposed along a perimeter of the openings so as to shape the electric field of the electromagnetic radiation in a cavity coupled to the coupler.

Millimeter-wave coupler for semi-confocal fabry-perot cavity

A backscatter modulator for providing low power wireless communications. The disclosed modulator provides phase control for discriminating backscatter from the antenna versus other objects. In addition, the disclosed backscatter modulator provides amplitude modulation so that the technique can provide a non-constant envelope which can provide an intentional imbalance to manipulate super-position to provide envelope control of the reflected signal, while still maintaining the frequency translation properties. The disclosed backscatter modulator thus allows compatibility with QAM, OFDM and other non-constant envelope modulation schemes to be backscattered, while still supporting the frequency translation behavior.

Frequency translating backscatter modulator with envelope control to support OFDM/QAM and other envelope modulated wireless protocols

Communication between a wireless base-station and a microwave reflector link are enhanced by feeding back a portion of the transmitter signal, adjusted for phase and amplitude, to cancel ambient reflection blocker signals being received at the base-station. The microwave reflector link does not utilize a transmitter gain stage, but communicates data back to the base-station in response to modulating the reflections of its antenna (e.g., in gain and/or phase). The disclosure aids in the proper amplification and processing of reflection signals from the microwave reflector link, by canceling out the blocking signals which arise as background objects reflect transmitter signal energy back to the base-station.

Reduction of unmodulated ambient blockers in reflected data links through manipulation or replication of the transmitting signal source

Non-contact position and motion sensing is improved for oscillator frequency based sensors in response to adding a two phase calibration along with bootstrapping circuit. Calibration is performed across the multiple sensor channels, so that: (1) maximum sensor channel loading is determined, and (2) the amount of capacitive load required for each other channel to match this same maximum load is stored for application to that channel during non-contact sensing. Capacitive coupling between channels is nullified by a bootstrapping process, in which time-domain voltage on the active channel is replicated on the non-active channels during non-contact sensing, thus creating equal potentials across inter-channel couplings that effectively eliminate inter-channel capacitive loading.

Bootstrapped and correlated double sampling (BCDS) non-contact touch sensor for mobile devices

A system, method, device, and apparatus provide a dielectric waveguide splitter/bi-directional link. A dielectric substrate fabricated into a first Y-junction waveguide with a first port splitting into a first branch leading to a second port and a second branch leading to a third port. An angle between the first branch and the second branch is below ninety degrees (90&#xb0;). The dielectric waveguide splitter enables millimeter-wave (mmWave) transmission between the first port and the second port while reducing feedback of the mmWave between the second and third port. Two Y-junction waveguides may be fabricated back-to-back to provide simultaneous bidirectional mmWave transmission at a single frequency.

Dielectric waveguides splitter and hybrid/isolator for bidirectional link

A lens for interconnecting a metallic waveguide with a dielectric waveguide is provided. The lens may be coupled a metallic waveguide and a dielectric waveguide, and minimize a signal loss between the metallic waveguide and the dielectric waveguide.

Interconnect between a waveguide and a dielectric waveguide comprising an impedance matched dielectric lens

A sub-carrier successive approximation (SCSA) radar having a sufficiently high accuracy to capture 3D images of concealed objects. The invention is phase-based, and directly measures round trip time by estimating the phase delay of the carrier. One of its advantages is that the carrier does not need to sweep across a wide frequency range, thereby relaxing RF front-end bandwidth and linearity requirements. SCSA radar accuracy is limited only by the extent of system noise, allowing very high accuracy to be achieved with a sufficient integration period. The SCSA radar can be readily implemented in CMOS, as well as other device technologies, and fabricated within one or more small integrated circuits.

Sub-carrier successive approximation millimeter wave radar for high-accuracy 3D imaging

A millimeter and sub-millimeter wavelength receiver imaging apparatus and method which directly generates a time encoded digital signal for an imaging pixel in response to interoperation of a digital quench circuit, an envelope detector, and a regenerative oscillator coupled to an antenna. The device utilizes the fact that oscillator startup time in a regenerative oscillator is inversely proportional to injected pixel image power. A digital quench circuit, such as a latch, is coupled for activating and deactivating the regenerative oscillator in response to receiving an output from an envelope threshold circuit, and for generating a time encoded digital signal in response to pixel amplitude during millimeter and sub-millimeter wavelength imaging. Receiver embodiments are described for both fundamental frequency operation (DRR) and for multi-frequency imaging (IRR).

Growing community of inventors

Pasadena, CA, United States of America

Adrian Tang