Leland Stanford Junior University

Facebook, Inc.

Emily McMilin

Mayank Jain

Shizhe Shen

Per Kristian Enge

David S De Lorenzo

Dinesh Bharadia

Fraidun Akhi

Sachin Katti

Dennis M Akos

Jung Il Choi

Kannan Srinivasan

There is provided an apparatus comprising an antenna () configured to receive a signal from a global navigation satellite system, wherein the antenna includes a first feed and a second feed; a hybrid coupler () including a first hybrid input, a second hybrid input, a first hybrid output, a second hybrid output, and wherein the first hybrid output is shifted in phase by 90 degrees relative to the second hybrid output; a variable phase shifter () including a shifter input and a shifter output, hybrid output; and a combiner () including a first combiner input, a second combiner input, and a combiner output, wherein the first combiner input is coupled to the shifter output, and the second combiner input is coupled to the second hybrid output, and wherein the combiner output is provided to detection circuitry ().

Spoofing detection and anti-jam mitigation for GPS antennas

A wireless communication device includes, in part, an analog interference cancellation circuit and a controller. The analog cancellation circuit includes a multitude of delay paths each including a delay element and a variable attenuator. The controller dynamically varies the attenuation level of each of the variable attenuators in accordance with the frequency response characteristic of that attenuator to remove a portion of a self-interference signal present in a signal received by the device. The device measures the frequency response characteristic of the communication channel, used in determining the attenuation levels, via one or more preamble symbols. A second portion of the self-interference signal is removed by the device using a multitude of samples of a transmitted signal and a multitude of samples of a signal to be transmitted.

Self-interference cancellation

Various of the disclosed embodiments use ITO and ITO-like materials or structures to serve as a waveguide for device communications, e.g., for mobile phone communication. Various embodiments employ an economical design, wherein one or more wireless antennas are integrated into or in conjunction with the display of a communications device as a waveguide antenna. The waveguide may use space more economically than traditional designs. In some embodiments, the waveguide can provide a wider range of viable operational frequencies. Additionally, in some embodiments, a square surface area of the waveguide optimizes the area to length ratio, which may reduce the resistance when the structure includes a lossy material. The waveguide antenna may be composed of ITO or ITO-like materials, which facilitate waveguide propagation while retaining a visually transparent character.

Waveguides for digital communication devices

Growing community of inventors

Palo Alto, CA, United States of America

Emily McMilin