Patents by Inventor Ramaswamy Mahadevan

Ramaswamy Mahadevan 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: 6360539
    Abstract: Microelectromechanical actuators include a substrate, spaced apart supports on the substrate and a thermal arched beam that extends between the spaced apart supports and that further arches upon heating thereof, for movement along the substrate. One or more driven arched beams are coupled to the thermal arched beam. The end portions of the driven arched beams move relative to one another to change the arching of the driven arched beams in response to the further arching of the thermal arched beam, for movement of the driven arched beams. A driven arched beam also includes an actuated element at an intermediate portion thereof between the end portions, wherein a respective actuated element is mechanically coupled to the associated driven arched beam for movement therewith, and is mechanically decoupled from the remaining driven arched beams for movement independent thereof.
    Type: Grant
    Filed: April 5, 2000
    Date of Patent: March 26, 2002
    Assignee: JDS Uniphase Corporation
    Inventors: Edward A. Hill, Vijayakumar R. Dhuler, Allen B. Cowen, Ramaswamy Mahadevan, Robert L. Wood
  • Publication number: 20020018334
    Abstract: MEMS devices include a substrate, an anchor attached to the substrate, and a multilayer member attached to the anchor and spaced apart from the substrate. The multilayer member can have a first portion that is remote from the anchor and that curls away from the substrate and a second portion that is adjacent the anchor that contacts the substrate. Related methods are also disclosed.
    Type: Application
    Filed: March 30, 2001
    Publication date: February 14, 2002
    Inventors: Edward A. Hill, Ramaswamy Mahadevan
  • Publication number: 20020011758
    Abstract: A MEMs microactuator can be positioned in an interior region of a frame having at least one opening therein, wherein the frame expands in response to a change in temperature of the frame. A load outside the frame can be coupled to the microactuator through the at least one opening. The microactuator moves relative to the frame in response to the change in temperature to remain substantially stationary relative to the substrate. Other MEMs structures, such as latches that can engage and hold the load in position, can be located outside the frame. Accordingly, in comparison to some conventional structures, temperature compensated microactuators according to the present invention can be made more compact by having the interior region of the frame free of other MEMs structures such as latches.
    Type: Application
    Filed: September 26, 2001
    Publication date: January 31, 2002
    Inventors: Vivek Agrawal, Robert L. Wood, Ramaswamy Mahadevan
  • Patent number: 6333583
    Abstract: Improved microelectromechanical structures include spaced-apart supports on a microelectronic substrate and a beam that extends between the spaced-apart supports and that expands upon application of heat thereto to thereby cause displacement of the beam between the spaced-apart supports. A heater, located on the beam, applies heat to the beam and displaces with the beam as the beam displaces. Therefore, heat can be directly applied to the arched beam, thereby reducing thermal loss between the heater and the arched beam. Furthermore, an air gap between the heater and arched beam may not need to be heated, thereby allowing improved transient thermal response. Moreover, displacing the heater as the arched beam displaces may further reduce thermal loss and transient thermal response by reducing the separation between the heater and the arched beam as the arched beam displaces.
    Type: Grant
    Filed: March 28, 2000
    Date of Patent: December 25, 2001
    Assignee: JDS Uniphase Corporation
    Inventors: Ramaswamy Mahadevan, Edward A. Hill, Robert L. Wood, Allen Cowen
  • Publication number: 20010050232
    Abstract: MEMS structures are provided that compensate for ambient temperature changes, process variations, and the like, and can be employed in many applications. These structures include an active microactuator adapted for thermal actuation to move in response to the active alteration of its temperature. The active microactuator may be further adapted to move in response to ambient temperature changes. These structures also include a temperature compensation element, such as a temperature compensation microactuator or frame, adapted to move in response to ambient temperature changes. The active microactuator and the temperature compensation element move cooperatively in response to ambient temperature changes. Thus, a predefined spatial relationship is maintained between the active microactuator and the associated temperature compensation microactuator over a broad range of ambient temperatures absent active alteration of the temperature of the active microactuator.
    Type: Application
    Filed: March 15, 2001
    Publication date: December 13, 2001
    Inventors: Edward Hill, Robert L. Wood, Ramaswamy Mahadevan
  • Patent number: 6324748
    Abstract: A MEMS actuator is provided that produces significant forces and displacements while consuming a reasonable amount of power. The MEMS actuator includes a microelectronic substrate, spaced apart supports on the substrate and a metallic arched beam extending between the spaced apart supports. The MEMS actuator also includes a heater for heating the arched beam to cause further arching of the beam. In order to effectively transfer heat from the heater to the metallic arched beam, the metallic arched beam extends over and is spaced, albeit slightly, from the heater. As such, the MEMS actuator effectively converts the heat generated by the heater into mechanical motion of the metallic arched beam. A family of other MEMS devices, such as relays, switching arrays and valves, are also provided that include one or more MEMS actuators in order to take advantage of its efficient operating characteristics. In addition, a method of fabricating a MEMS actuator is further provided.
    Type: Grant
    Filed: January 19, 1999
    Date of Patent: December 4, 2001
    Assignee: JDS Uniphase Corporation
    Inventors: Vijayakumar R. Dhuler, Robert L. Wood, Ramaswamy Mahadevan
  • Patent number: 6275320
    Abstract: A MEMS (Micro Electro Mechanical System) variable optical attenuator is provided that is capable of optical attenuation over a full range of optical power. The MEMS variable optical attenuator comprises a microelectronic substrate, a MEMS actuator and an optical shutter. The MEMS variable optical attenuator may also comprise a clamping element capable of locking the optical shutter at a desired attenuation position. The variable light attenuator is capable of attenuating optical beams that have their optical axis running parallel and perpendicular to the substrate. Additionally, the MEMS actuator of the present invention may comprise an array of MEMS actuators capable of supplying the optical shutter with greater displacement distances and, thus a fuller range of optical attenuation. In one embodiment of the invention, the MEMS actuator comprises a thermal arched beam actuator. Additionally, the variable optical attenuator of the present invention may be embodied in a thermal bimorph cantilever structure.
    Type: Grant
    Filed: September 27, 1999
    Date of Patent: August 14, 2001
    Assignee: JDS Uniphase, Inc.
    Inventors: Vijayakumar R. Dhuler, Edward A. Hill, Ramaswamy Mahadevan, Mark David Walters, Robert L. Wood
  • Patent number: 6262512
    Abstract: Microelectromechanical structures include a microelectronic substrate and spaced apart supports on the microelectronic substrate. A beam extends between the spaced apart supports and expands upon application of heat thereto, to thereby cause displacement of the beam between the spaced apart supports. The application of heat to the beam creates a thermal conduction path from the beam through the spaced apart supports and into the substrate. A thermal isolation structure in the heat conduction path reduces thermal conduction from the beam, through the spaced apart supports and into the substrate, compared to absence of the thermal isolation structure. The thermal isolation structure preferably has lower thermal conductivity than the beam and the supports. The heat that remains in the beam thereby can be increased.
    Type: Grant
    Filed: November 8, 1999
    Date of Patent: July 17, 2001
    Assignee: JDS Uniphase Inc.
    Inventor: Ramaswamy Mahadevan
  • Patent number: 6236139
    Abstract: MEMS structures are provided that compensate for ambient temperature changes, process variations, and the like, and can be employed in many applications. These structures include an active microactuator adapted for thermal actuation to move in response to the active alteration of its temperature. The active microactuator may be further adapted to move in response to ambient temperature changes. These structures also include a temperature compensation element, such as a temperature compensation microactuator or frame, adapted to move in response to ambient temperature changes. The active microactuator and the temperature compensation element move cooperatively in response to ambient temperature changes. Thus, a predefined spatial relationship is maintained between the active microactuator and the associated temperature compensation microactuator over a broad range of ambient temperatures absent active alteration of the temperature of the active microactuator.
    Type: Grant
    Filed: February 26, 1999
    Date of Patent: May 22, 2001
    Assignee: JDS Uniphase Inc.
    Inventors: Edward Hill, Robert L. Wood, Ramaswamy Mahadevan
  • Patent number: 6229684
    Abstract: A variable capacitor having low loss and a correspondingly high Q is provided. In addition to a substrate, the variable capacitor includes at least one substrate electrode and a substrate capacitor plate that are disposed upon the substrate and formed of a low electrical resistance material, such as HTS material or a thick metal layer. The variable capacitor also includes a bimorph member extending outwardly from the substrate and over the at least one substrate electrode. The bimorph member includes first and second layers formed of materials having different coefficients of thermal expansion. The first and second layers of the bimorph member define at least one bimorph electrode and a bimorph capacitor plate such that the establishment of a voltage differential between the substrate electrode and the bimorph electrode moves the bimorph member relative to the substrate electrode, thereby altering the interelectrode spacing as well as the distance between the capacitor plates.
    Type: Grant
    Filed: December 15, 1999
    Date of Patent: May 8, 2001
    Assignee: JDS Uniphase Inc.
    Inventors: Allen Bruce Cowen, Vijayakumar Rudrappa Dhuler, Edward Arthur Hill, David Alan Koester, Ramaswamy Mahadevan
  • Patent number: 6114794
    Abstract: A MEMS actuator is provided that produces significant forces and displacements while consuming a reasonable amount of power. The MEMS actuator includes a microelectronic substrate, spaced apart supports on the substrate and a metallic arched beam extending between the spaced apart supports. The MEMS actuator also includes a heater for heating the arched beam to cause further arching of the beam. In order to effectively transfer heat from the heater to the metallic arched beam, the metallic arched beam extends over and is spaced, albeit slightly, from the heater. As such, the MEMS actuator effectively converts the heat generated by the heater into mechanical motion of the metallic arched beam. A family of other MEMS devices, such as relays, switching arrays and valves, are also provided that include one or more MEMS actuators in order to take advantage of its efficient operating characteristics. In addition, a method of fabricating a MEMS actuator is further provided.
    Type: Grant
    Filed: January 19, 1999
    Date of Patent: September 5, 2000
    Assignee: Cronos Integrated Microsystems, Inc.
    Inventors: Vijayakumar R. Dhuler, Robert L. Wood, Ramaswamy Mahadevan
  • Patent number: 6023121
    Abstract: A MEMS actuator is provided that produces significant forces and displacements while consuming a reasonable amount of power. The MEMS actuator includes a microelectronic substrate, spaced apart supports on the substrate and a metallic arched beam extending between the spaced apart supports. The MEMS actuator also includes a heater for heating the arched beam to cause further arching of the beam. In order to effectively transfer heat from the heater to the metallic arched beam, the metallic arched beam extends over and is spaced, albeit slightly, from the heater. As such, the MEMS actuator effectively converts the heat generated by the heater into mechanical motion of the metallic arched beam. A family of other MEMS devices, such as relays, switching arrays and valves, are also provided that include one or more MEMS actuators in order to take advantage of its efficient operating characteristics. In addition, a method of fabricating a MEMS actuator is further provided.
    Type: Grant
    Filed: January 19, 1999
    Date of Patent: February 8, 2000
    Assignee: MCNC
    Inventors: Vijayakumar R. Dhuler, Robert L. Wood, Ramaswamy Mahadevan
  • Patent number: 5994816
    Abstract: A MEMS actuator is provided that produces significant forces and displacements while consuming a reasonable amount of power. The MEMS actuator includes a microelectronic substrate, spaced apart supports on the substrate and a metallic arched beam extending between the spaced apart supports. The MEMS actuator also includes a heater for heating the arched beam to cause further arching of the beam. In order to effectively transfer heat from the heater to the metallic arched beam, the metallic arched beam extends over and is spaced, albeit slightly, from the heater. As such, the MEMS actuator effectively converts the heat generated by the heater into mechanical motion of the metallic arched beam. A family of other MEMS devices, such as relays, switching arrays and valves, are also provided that include one or more MEMS actuators in order to take advantage of its efficient operating characteristics. In addition, a method of fabricating a MEMS actuator is further provided.
    Type: Grant
    Filed: September 24, 1997
    Date of Patent: November 30, 1999
    Assignee: MCNC
    Inventors: Vijayakumar R. Dhuler, Robert L. Wood, Ramaswamy Mahadevan
  • Patent number: 5955817
    Abstract: A MEMS actuator is provided that produces significant forces and displacements while consuming a reasonable amount of power. The MEMS actuator includes a microelectronic substrate, spaced apart supports on the substrate and a metallic arched beam extending between the spaced apart supports. The MEMS actuator also includes a heater for heating the arched beam to cause further arching of the beam. In order to effectively transfer heat from the heater to the metallic arched beam, the metallic arched beam extends over and is spaced, albeit slightly, from the heater. As such, the MEMS actuator effectively converts the heat generated by the heater into mechanical motion of the metallic arched beam. A family of other MEMS devices, such as relays, switching arrays and valves, are also provided that include one or more MEMS actuators in order to take advantage of its efficient operating characteristics. In addition, a method of fabricating a MEMS actuator is further provided.
    Type: Grant
    Filed: January 19, 1999
    Date of Patent: September 21, 1999
    Assignee: MCNC
    Inventors: Vijayakumar R. Dhuler, Robert L. Wood, Ramaswamy Mahadevan
  • Patent number: 5311305
    Abstract: Edges/corners in an image can be detected and tracked over time by first sampling the image at periodic time intervals, and then processing the samples to obtain the intensity value for each pixel within each image acquired at a particular time. For each pixel, the bidirectional intraframe correlation of its intensity with the intensities of pixels along each of several directions within the same image is computed. Also, the bidirectional interframe correlation of the intensity of each pixel in each image with the intensities of pixels along each of several directions spanning several images is established. The intraframe and interframe intensity correlations are processed to obtain spatiotemporal tangent information about isobrightness surfaces and curves which are indicative of edges and corners, respectively, and their image motions.
    Type: Grant
    Filed: June 30, 1992
    Date of Patent: May 10, 1994
    Assignee: AT&T Bell Laboratories
    Inventors: Ramaswamy Mahadevan, Vishvjit S. Nalwa