Patents by Inventor Narayanan Rajan

Narayanan Rajan 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: 7203393
    Abstract: An array of electrostatically tiltable mirrors are formed in a MEMS structure. A first SOI wafer is etched to form an array of tiltable plates in the silicon device layer joined to the remainder of the wafer through pairs of torsion beams. A second SOI wafer is etched to form cavities corresponding to the tiltable plates. A ceramic multi-chip module (MCM) carrier is formed with multiple layers of wiring and electrodes corresponding to the tiltable plates. The two SOI wafers including their handle layers are bonded together. The handle layer of the second SOI is removed, and the bonded wafers are diced into chips. Each chip is bonded to a respective MCM carrier. Thereafter, the handle layer of the first SOI wafer is removed to release the tiltable mirror plates and the torsion beams. Electronic control chips may be bonded to the MCM carrier.
    Type: Grant
    Filed: November 7, 2002
    Date of Patent: April 10, 2007
    Assignee: Movaz Networks, Inc.
    Inventors: Narayanan Rajan, Chien Hung Wu, Jay S. Mitchell, Lucy Huang
  • Patent number: 6788981
    Abstract: A multiplexed analog control system for an micro electromechanical systems (MEMS) array of electrostatic actuators, such as tiltable mirrors in an optical switch. Each actuator includes a variable gap capacitor formed as part of the movable mechanical element. A hold capacitor is connected to each actuator capacitor, and a selectable high-voltage inverter connects them to provide a bipolar drive signal of 50% duty cycle. A single power digital controlled current source is connected to all the drive circuits to provide a high-power correction signal. Address decoders enable a selected one of the drive circuits to add or subtract the correction from the hold capacitor.
    Type: Grant
    Filed: September 7, 2001
    Date of Patent: September 7, 2004
    Assignee: Movaz Networks, Inc.
    Inventors: Steven L. Garverick, Jun Guo, Narayanan Rajan
  • Publication number: 20030169962
    Abstract: An array of electrostatically tiltable mirrors are formed in a MEMS structure. A first SOI wafer is etched to form an array of tiltable plates in the silicon device layer joined to the remainder of the wafer through pairs of torsion beams. A second SOI wafer is etched to form cavities corresponding to the tiltable plates. A ceramic multi-chip module (MCM) carrier is formed with multiple layers of wiring and electrodes corresponding to the tiltable plates. The two SOI wafers including their handle layers are bonded together. The handle layer of the second SOI is removed, and the bonded wafers are diced into chips. Each chip is bonded to a respective MCM carrier. Thereafter, the handle layer of the first SOI wafer is removed to release the tiltable mirror plates and the torsion beams. Electronic control chips may be bonded to the MCM carrier.
    Type: Application
    Filed: November 7, 2002
    Publication date: September 11, 2003
    Inventors: Narayanan Rajan, Chien Hung Wu, Jay S. Mitchell, Lucy Huang
  • Publication number: 20030122206
    Abstract: An integrated module including an array of electrostatically actuated mirrors usable as an optical switch. An array of tiltable mirrors is formed as a micro electromechanical system (MEMS) in one carrier substrate. A ceramic multi-chip module (MCM) is formed having multiple layers of wiring and electrodes at one surface forming one side part of the electrostatic capacitive actuators. The MEMS substrate is bonded to the carrier with the carrier electrodes in opposition to the mirrors, which form counter electrodes. Advantageously, a handle layer of the MEMS substrate is not removed and the mirrors released until after the bonding with the MCM. Separate high-voltage integrated circuits (ICs) driving the actuators and low-voltage ICs controlling the high-voltage ICs are bonded on the side of the MCM opposite the MEMS with the MCM providing electrical interconnections.
    Type: Application
    Filed: November 7, 2002
    Publication date: July 3, 2003
    Inventors: Amal Bhattarai, Narayanan Rajan
  • Publication number: 20020106144
    Abstract: A multiplexed analog control system for an micro electromechanical systems (MEMS) array of electrostatic actuators, such as tiltable mirrors in an optical switch. Each actuator includes a variable gap capacitor formed as part of the movable mechanical element. A hold capacitor is connected to each actuator capacitor, and a selectable high-voltage inverter connects them to provide a bipolar drive signal of 50% duty cycle. A single power digital controlled current source is connected to all the drive circuits to provide a high-power correction signal. Address decoders enable a selected one of the drive circuits to add or subtract the correction from the hold capacitor.
    Type: Application
    Filed: September 7, 2001
    Publication date: August 8, 2002
    Inventors: Steven L. Garverick, Jun Guo, Narayanan Rajan
  • Patent number: 6136243
    Abstract: A method for molding high precision components is provided that allows inexpensive, rapid fabrication of components using a process involving a silicon substrate, in which the mold pattern is created using multiple mask layers, a deep reactive ion etch process and photolithographic patterning techniques.
    Type: Grant
    Filed: June 4, 1998
    Date of Patent: October 24, 2000
    Assignee: Case Western Reserve University
    Inventors: Mehran Mehregany, Narayanan Rajan, Christian A. Zorman