Patents by Inventor Abhay M. Joshi

Abhay M. Joshi has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 11500615
    Abstract: A pseudo-random sequence generator for use within a universal lidar system and its corresponding method of operation. The pseudo-random sequence generator uses synchronized shift registers that are in series Binary adders are provided. The signal output of each of the shift registers is tapped and directed to the binary adders. High-speed switches are provided between the shift registers and the binary adders. The switches are programmed to connect only two of the shift registers to the binary adders for each of the pseudo-random patterns being generated. The binary adders generate an output signal that is received by the first shift register. The signal propagates through all the shift registers to the last shift register. The last shift register outputs a pseudo-random sequence.
    Type: Grant
    Filed: May 4, 2020
    Date of Patent: November 15, 2022
    Assignee: Discovery Semiconductors, Inc.
    Inventors: Shubhashish Datta, Abhay M. Joshi
  • Publication number: 20200356346
    Abstract: A pseudo-random sequence generator for use within a universal lidar system and its corresponding method of operation. The pseudo-random sequence generator uses synchronized shift registers that are in series Binary adders are provided. The signal output of each of the shift registers is tapped and directed to the binary adders. High-speed switches are provided between the shift registers and the binary adders. The switches are programmed to connect only two of the shift registers to the binary adders for each of the pseudo-random patterns being generated. The binary adders generate an output signal that is received by the first shift register. The signal propagates through all the shift registers to the last shift register. The last shift register outputs a pseudo-random sequence.
    Type: Application
    Filed: May 4, 2020
    Publication date: November 12, 2020
    Inventors: Shubhashish Datta, Abhay M. Joshi
  • Patent number: 8598673
    Abstract: A quad photoreceiver includes a low capacitance quad InGaAs p-i-n photodiode structure formed on an InP (100) substrate. The photodiode includes a substrate providing a buffer layer having a metal contact on its bottom portion serving as a common cathode for receiving a bias voltage, and successive layers deposited on its top portion, the first layer being drift layer, the second being an absorption layer, the third being a cap layer divided into four quarter pie shaped sections spaced apart, with metal contacts being deposited on outermost top portions of each section to provide output terminals, the top portions being active regions for detecting light. Four transimpedance amplifiers have input terminals electrically connected to individual output terminals of each p-i-n photodiode.
    Type: Grant
    Filed: August 23, 2010
    Date of Patent: December 3, 2013
    Assignee: Discovery Semiconductors, Inc.
    Inventors: Abhay M. Joshi, Shubhashish Datta
  • Patent number: 8126338
    Abstract: Repeaterless transmission of differential phase-shift keying (DPSK) at 10.7 Gb/s over at least 304 km of standard single-mode fiber is obtained through use of a coherent optical receiver including electronic dispersion compensation. High receiver sensitivity and high tolerance to nonlinearities of DPSK, allow overcoming a total link loss of 58 dB with a 3 dB system margin, through use in the receiver of heterodyne detection to preserve phase distortions resulting from chromatic dispersion, to permit electronic dispersion compensation to be used.
    Type: Grant
    Filed: October 29, 2008
    Date of Patent: February 28, 2012
    Assignee: Discovery Semiconductors, Inc.
    Inventors: Christoph T. Wree, Suhas P. Bhandare, Donald A. Becker, Daniel R. Mohr, Abhay M. Joshi
  • Publication number: 20120043584
    Abstract: A quad photoreceiver includes a low capacitance quad InGaAs p-i-n photodiode structure formed on an InP (100) substrate. The photodiode includes a substrate providing a buffer layer having a metal contact on its bottom portion serving as a common cathode for receiving a bias voltage, and successive layers deposited on its top portion, the first layer being drift layer, the second being an absorption layer, the third being a cap layer divided into four quarter pie shaped sections spaced apart, with metal contacts being deposited on outermost top portions of each section to provide output terminals, the top portions being active regions for detecting light. Four transimpedance amplifiers have input terminals electrically connected to individual output terminals of each p-i-n photodiode.
    Type: Application
    Filed: August 23, 2010
    Publication date: February 23, 2012
    Inventors: Abhay M. Joshi, Shubhashish Datta
  • Publication number: 20090142069
    Abstract: Repeaterless transmission of differential phase-shift keying (DPSK) at 10.7 Gb/s over at least 304 km of standard single-mode fiber is obtained through use of a coherent optical receiver including electronic dispersion compensation. High receiver sensitivity and high tolerance to nonlinearities of DPSK, allow overcoming a total link loss of 58 dB with a 3 dB system margin, through use in the receiver of heterodyne detection to preserve phase distortions resulting from chromatic dispersion, to permit electronic dispersion compensation to be used.
    Type: Application
    Filed: October 29, 2008
    Publication date: June 4, 2009
    Inventors: Christoph T. Wree, Suhas P. Bhandare, Donald A. Becker, Daniel R. Mohr, Abhay M. Joshi
  • Patent number: 7406269
    Abstract: An optical coherent receiver in one embodiment has a heterodyne configuration, and in another embodiment has a homodyne configuration, in each configuration employs multiple feedback signaling and analog/digital processing to optimize response to a modulated optical input signal, the provision of both individual RF I and RF Q channel outputs.
    Type: Grant
    Filed: February 27, 2007
    Date of Patent: July 29, 2008
    Assignee: Discovery Semiconductors, Inc.
    Inventors: Donald A. Becker, Daniel R. Mohr, Christoph T. Wree, Abhay M. Joshi
  • Patent number: 6137171
    Abstract: A plurality of silicon and GaAs wafers each including integrated circuitry for providing particular functions for each wafer are mounted within a housing in a stacked, spaced apart, and parallel configuration. Photodetectors and LED's are used to transmit and receive data between opposing wafers. In this manner a micro-packaged device or system is obtained for use amongst other things in lightweight miniaturized microsatellites.
    Type: Grant
    Filed: October 23, 1998
    Date of Patent: October 24, 2000
    Assignee: Discovery Semiconductors, Inc.
    Inventor: Abhay M. Joshi
  • Patent number: 5621227
    Abstract: A monolithic Optoelectronic Integrated Circuit including a photodiode and a CMOS readout circuit is described in which the diode is formed by compositionally graded layers of In.sub.x Ga.sub.1-x As selectively epitaxially grown between a substrate of Si and an absorption layer of In.sub.x Ga.sub.1-x As, the areas of said layers being less than 500 .mu.m.sup.2 and wherein a readout circuit on said substrate is coupled to said diode.
    Type: Grant
    Filed: July 18, 1995
    Date of Patent: April 15, 1997
    Assignee: Discovery Semiconductors, Inc.
    Inventor: Abhay M. Joshi
  • Patent number: 5387796
    Abstract: Leakage current in InGaAs/InAsP/InP lattice mismatched photodetectors can be reduced by providing graded InAsP compositions having abrupt interfaces between successive layers that maintain a lattice mismatch between the layers of 0.13% or less; doping the absorption layer with high levels of sulfur and by thermal cycling of the wafers. High yields of low leakage current photodetector arrays are obtained.
    Type: Grant
    Filed: May 26, 1993
    Date of Patent: February 7, 1995
    Assignee: Epitaxx, Inc.
    Inventors: Abhay M. Joshi, Krishna R. Linga