California Institute of Technology

Coherent, Inc.

United States of America As Represented by the Administrator of Nasa

Huntington Medical Research Institutes

Peter H Siegel

Goutam Chattopadhyay

Robert J Dengler

Imran Mehdi

Eric R Mueller

Ken B Cooper

John Strawn Ward

Nuria Llombart Juan

Anders J Skalare

Scott E Fraser

Harish M Manohara

Choonsup Lee

John J Gill

Tomas Bryllert

Erich T Schlecht

Cavour Yeh

Victor Pikov

Fred Shimabukuro

Barbara Wilson

Jan A Tarsala

A device is described for interrogating human skin using tight coupling between the transmitter and receiver of the millimeter waves (MMWs). Methods are provided to evaluate changes in the amplitude and/or phase of the transmitted MMWs in order to estimate the blood concentration of glucose. Using this device and the related methods, the blood glucose concentration or a change in the blood glucose concentration can be monitored for diagnosing diabetes mellitus and other metabolic disorders of carbohydrate metabolism characterized by either high blood glucose level (hyperglycemia) or low blood glucose level (hypoglycemia), as well as for monitoring (including self-monitoring) a metabolic disorder progression or an efficacy of treatment.

Methods and systems for non-invasive measurement of blood glucose concentration by transmission of millimeter waves through human skin

An antenna element suitable for integrated arrays at terahertz frequencies is disclosed. The antenna element comprises an extended spherical (e.g. hemispherical) semiconductor lens, e.g. silicon, antenna fed by a leaky wave waveguide feed. The extended spherical lens comprises a substantially spherical lens adjacent a substantially planar lens extension. A couple of TE/TM leaky wave modes are excited in a resonant cavity formed between a ground plane and the substantially planar lens extension by a waveguide block coupled to the ground plane. Due to these modes, the primary feed radiates inside the lens with a directive pattern that illuminates a small sector of the lens. The antenna structure is compatible with known semiconductor fabrication technology and enables production of large format imaging arrays.

Dielectric covered planar antennas

A three-dimensional imaging radar operating at high frequency e.g., 670 GHz radar using low phase-noise synthesizers and a fast chirper to generate a frequency-modulated continuous-wave (FMCW) waveform, is disclosed that operates with a multiplexed beam to obtain range information simultaneously on multiple pixels of a target. A source transmit beam may be divided by a hybrid coupler into multiple transmit beams multiplexed together and directed to be reflected off a target and return as a single receive beam which is demultiplexed and processed to reveal range information of separate pixels of the target associated with each transmit beam simultaneously. The multiple transmit beams may be developed with appropriate optics to be temporally and spatially differentiated before being directed to the target. Temporal differentiation corresponds to a different intermediate frequencies separating the range information of the multiple pixels. Collinear transmit beams having differentiated polarizations may also be implemented.

Multi-pixel high-resolution three-dimensional imaging radar

In an embodiment, a submillimeter wave heterodyne receiver includes a finline ortho-mode transducer comprising thin tapered metallic fins deposited on a thin dielectric substrate to separate a vertically polarized electromagnetic mode from a horizontally polarized electromagnetic mode. Other embodiments are described and claimed.

Submillimeter wave heterodyne receiver

A three-dimensional imaging radar operating at high frequency e.g., 670 GHz, is disclosed. The active target illumination inherent in radar solves the problem of low signal power and narrow-band detection by using submillimeter heterodyne mixer receivers. A submillimeter imaging radar may use low phase-noise synthesizers and a fast chirper to generate a frequency-modulated continuous-wave (FMCW) waveform. Three-dimensional images are generated through range information derived for each pixel scanned over a target. A peak finding algorithm may be used in processing for each pixel to differentiate material layers of the target. Improved focusing is achieved through a compensation signal sampled from a point source calibration target and applied to received signals from active targets prior to FFT-based range compression to extract and display high-resolution target images. Such an imaging radar has particular application in detecting concealed weapons or contraband.

High-resolution three-dimensional imaging radar

The present invention relates to sub-millimeter wave frequency heterodyne imaging systems. More specifically, the present invention relates to a sub-millimeter wave frequency heterodyne detector system for imaging the magnitude and phase of transmitted power through or reflected power off of mechanically scanned samples at sub-millimeter wave frequencies.

Sub-millimeter wave frequency heterodyne detector system

The present invention relates to the field of radio-frequency (RF) waveguides. More specifically, the present invention pertains to a method and apparatus that provides ultra-low-loss RF waveguide structures targeted between approximately 300 GHz and approximately 30 THz. The RF waveguide includes a hollow core and a flexible honeycomb, periodic-bandgap structure surrounding the hollow core. The flexible honeycomb, periodic-bandgap structure is formed of a plurality of tubes formed of a dielectric material such as of low-loss quartz, polyethylene, or high-resistivity silicon. Using the RF waveguide, a user may attach a terahertz signal source to the waveguide and pass signals through the waveguide, while a terahertz signal receiver receives the signals.

Method and apparatus for low-loss signal transmission

The invention is embodied in a monolithic semiconductor integrated circuit in which is formed an antenna, such as a slot dipole antenna, connected across a rectifying diode. In the preferred embodiment, the antenna is tuned to received an electromagnetic wave of about 2500 GHz so that the device is on the order of a wavelength in size, or about 200 microns across and 30 microns thick. This size is ideal for mounting on a microdevice such as a microrobot for example. The antenna is endowed with high gain in the direction of the incident radiation by providing a quarter-wavelength (30 microns) thick resonant cavity below the antenna, the cavity being formed as part of the monolithic integrated circuit. Preferably, the integrated circuit consists of a thin gallium arsenide membrane overlying the resonant cavity and supporting an epitaxial Gallium Arsenide semiconductor layer. The rectifying diode is a Schottky diode formed in the GaAs semiconductor layer and having an area that is a very small fraction of the wavelength of the 2500 GHz incident radiation. The cavity provides high forward gain in the antenna and isolation from surrounding structure.

Self-contained sub-millimeter wave rectifying antenna integrated circuit

The lift-off technique for transferring a preprocessed GaAs circuit to a quartz carrier is used to integrate GaAs active devices with distributed quartz microwave circuit elements (e.g., microstrip circuitry) in a single integrated circuit package. The present invention is therefore useful in making a variety of extremely rugged, low loss millimeter and submillimeter wave integrated circuits. By restricting the GaAs layer to a thin membrane and by impurity-doping the GaAs layer only in the regions of the active devices, the advantages of the quartz substrate in the presence of millimeter wave or submillimeter wave radiation are essentially retained.

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La Canada, CA, United States of America

Peter H Siegel