Search

Rahul Sarpeshkar Phones & Addresses

  • Hanover, NH
  • 27 Oakland Ave, Arlington, MA 02476
  • 10 Cornell St, Arlington, MA 02474
  • 25 Hickory Pl, Chatham, NJ 07928
  • 8 Field St, Cambridge, MA 02138
  • Pasadena, CA

Publications

Wikipedia References

Rahul Sarpeshkar Photo 1

Rahul Sarpeshkar

Work:
Area of science:

Physicist


Position:

Investigator • Economist

Education:
Academic degree:

Professor


Area of science:

Systems biology • Biotechnology • Cell biology

Skills & Activities:
Skill:

Analog • Scientific


Sport:

LIVING


Master status:

Blind


Preference:

Associate

Us Patents

Analog Computation Device Using Separated Analog Signals, Each Having A Specified Amount Of Resolution, And Signal Restoration Devices

View page
US Patent:
6377194, Apr 23, 2002
Filed:
Sep 29, 1999
Appl. No.:
09/408137
Inventors:
Rahul Sarpeshkar - Cambridge MA
Assignee:
California Institute of Technology - Pasadena CA
International Classification:
H03M 118
US Classification:
341110, 341116, 341158, 341143, 341162, 341 59, 341141
Abstract:
An analog computation system which forms a hybrid between analog and digital computation. The analog signal is divided into a plurality of separated analog signals, each of the different analog signals collectively representing the original analog signal, and each having less resolution then the total desired resolution. A number of different analog computation elements carry out a mathematical function on the separated signal. Different stages may be provided, and a signal restoration device may be provided between the different stages.

Display Comprising Organic Smart Pixels

View page
US Patent:
6384804, May 7, 2002
Filed:
Nov 25, 1998
Appl. No.:
09/199364
Inventors:
Ananth Dodabalapur - Millington NJ
Rahul Sarpeshkar - Chatham NJ
Assignee:
Lucent Techonologies Inc. - Murray Hill NJ
International Classification:
G09G 332
US Classification:
345 82, 345 76, 345205, 257 40
Abstract:
A display apparatus according to our invention comprises a multiplicity of nominally identical smart pixels, a given pixel comprising an organic light emitting diode and an organic or inorganic (e. g. , amorphous or polycrystalline Si) pixel FET. The display also comprises drive/compensation circuitry adapted for mitigating or eliminating non-idealities associated with the organic components. Among the non-idealities are variations in mobility and/or threshold voltage of the pixel FET from transistor to transistor, change in mobility and/or threshold voltage with time in a given pixel FET, change over time of the LED characteristics, capacitive signal feed-through through the gate insulator of the pixel FETs by short rise/fall time pulses, poor on-off ratio of the pixel FET, and charge leakage through the gate dielectric. Exemplary drive/compensation circuitry is disclosed.

Odor Sensing With Organic Transistors

View page
US Patent:
6484559, Nov 26, 2002
Filed:
Feb 26, 2001
Appl. No.:
09/793049
Inventors:
Ananth Dodabalapur - Millington NJ
Rahul Sarpeshkar - Arlington MA
Assignee:
Lucent Technologies Inc. - Murray Hill NJ
International Classification:
G01N 2712
US Classification:
73 2334, 73 3106, 73 2321, 324 715, 422 90
Abstract:
A circuit includes at least one odor-sensitive organic field effect transistor (OFET) having a conduction channel whose conductivity changes in response to certain ambient odors and a feedback loop coupled between an output and an input of the circuit. The feedback loop generates a feedback signal which stabilizes the output signal of the circuit for time drift of the odor-sensitive organic transistor. In one embodiment, the OFET is an integral part of an amplifier and generates input signals to the amplifier in response to certain odors. A selectively enabled switch may be coupled between the output and the input of the amplifier circuit to provide negative feedback that tends to cancel the effect on the amplifier of time drift due to the OFET.

Edge-Triggered Toggle Flip-Flop Circuit

View page
US Patent:
6621319, Sep 16, 2003
Filed:
Sep 29, 1999
Appl. No.:
09/407535
Inventors:
Ruben Herrera - New York NY
Rahul Sarpeshkar - Cambridge MA
Assignee:
Agere Systems Inc. - Allentown PA
International Classification:
H03K 3037
US Classification:
327221, 327199
Abstract:
An edge-triggered flip-flop circuit in which a pair of capacitors are alternately charged and discharged to voltages approximating supply rail values and, in combination of with a small number of switches, present high or low impedance paths for input signal transitions of a predetermined polarity to trigger state changes. In an alternative embodiment large switching capacitors are avoided in a circuit that employs a pair of pass-transistor configurations to connect respective capacitors to output terminals of a bistable device. The voltages on the capacitors track the corresponding bistable device output voltages when the input signal is in a given state (illustratively low), and store the value of the corresponding voltage when turned off by the (illustratively high) other state of the input signal. Then, the voltage on the capacitors and the selected input signal transition is used to effectively trigger a transition in the bistable device.

Optical Transient Sensor Having A Charge/Discharge Circuit

View page
US Patent:
6797934, Sep 28, 2004
Filed:
May 23, 2002
Appl. No.:
10/154514
Inventors:
Jörg Kramer - Zürich, CH
Rahul Sarpeshkar - Arlington MA
Assignee:
Eidgenossische Technische Hochschule Zurich - Zurich
Universitat Zurich - Zurich
International Classification:
H01L 3100
US Classification:
2502141, 250214 A
Abstract:
An optical transient sensor circuit includes a photodiode in series with a MOS feedback transistor connected across a voltage difference. An inverting amplifier having its input connected to the common connection between the photodiode and the MOS feedback transistor and its output connected to an output-node for a measure of the incoming irradiance. A charge/discharge circuit, having an input connected to the output of the inverting amplifier, having an output connected to the gate of the MOS feedback transistor and having a first and second output for half-wave rectified and thresholded contrast encoding measures of positive and negative irradiance transients. A capacitor connected between a constant potential and the gate of the MOS feedback transistor.

Organic Polarizable Gate Transistor Apparatus And Method

View page
US Patent:
6870180, Mar 22, 2005
Filed:
Jun 8, 2001
Appl. No.:
09/877844
Inventors:
Ananth Dodabalapur - Millington NJ, US
Howard E. Katz - Summit NJ, US
Rahul Sarpeshkar - Arlington MA, US
Assignee:
Lucent Technologies Inc. - Murray Hill NJ
International Classification:
H01L051/30
H01L029/76
US Classification:
257 40, 257314, 257405, 257406, 257410, 257411
Abstract:
An apparatus having a circuit coupled to the gate contact of field effect transistor wherein the transistor's gate includes a dielectric layer of which at least a portion is an organic dielectric. The circuit is configured to produce one or more storage voltage pulses that cause charge to be stored in the dielectric layer. The field effect transistor has a semiconductor layer with a conductive path whose conductivity changes for a given Vin response to storing the charge. The circuit may produce one or more dissipation voltage pulses having a voltage of opposite sign to the one or more storage pulses, that cause dissipation of charge stored in the dielectric layer. Further disclosed are a memory and a method of electronically storing and reading information, both utilizing the organic-based polarizable gate transistor apparatus.

Edge-Triggered Toggle Flip-Flop Circuit

View page
US Patent:
6882198, Apr 19, 2005
Filed:
Jul 8, 2003
Appl. No.:
10/614178
Inventors:
Ruben Herrera - New York NY, US
Rahul Sarpeshkar - Cambridge MA, US
Assignee:
Agere Systems Inc. - Allentown PA
International Classification:
H03K003/02
US Classification:
327197, 327208, 327218
Abstract:
An edge-triggered flip-flop circuit in which a pair of capacitors are alternately charged and discharged to voltages approximating supply rail values and, in combination of with a small number of switches, present high or low impedance paths for input signal transitions of a predetermined polarity to trigger state changes. In an alternative embodiment large switching capacitors are avoided in a circuit that employs a pair of pass-transistor configurations to connect respective capacitors to output terminals of a bistable device. The voltages on the capacitors track the corresponding bistable device output voltages when the input signal is in a given state (illustratively low), and store the value of the corresponding voltage when turned off by the (illustratively high) other state of the input signal. Then, the voltage on the capacitors and the selected input signal transition is used to effectively trigger a transition in the bistable device.

Low-Power Wide Dynamic Range Envelope Detector System And Method

View page
US Patent:
7095256, Aug 22, 2006
Filed:
Jul 16, 2004
Appl. No.:
10/892669
Inventors:
Serhii M. Zhak - Cambridge MA, US
Michael W. Baker - Cambridge MA, US
Rahul Sarpeshkar - Arlington MA, US
Assignee:
Massachusetts Institute of Technology - Cambridge MA
International Classification:
G01R 19/00
US Classification:
327 58, 327 59, 327 18
Abstract:
An envelope detector system is disclosed for detecting an envelope in a system input signal. The envelope detector system includes an input node for receiving an input voltage signal, a transconducting amplifier for receiving the input voltage signal and producing an input current signal, a current mirror network for receiving the input current signal and for producing a current output signal, a capacitor for receiving the current output signal, and a rectifier output node for providing a rectifier output current signal. The capacitor is coupled to an input of the transconducting amplifier. The rectifier output current signal is fed into the current-mode wide-dynamic-range peak detector. The peak detector produces the envelope detector output current signal.
Rahul Sarpeshkar from Hanover, NH, age ~53 Get Report