Patents by Inventor David I. Forehand

David I. Forehand 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: 7002441
    Abstract: A micro-electro-mechanical (MEMS) switch (10, 110) has an electrode (22, 122) covered by a dielectric layer (23, 123), and has a flexible conductive membrane (31, 131) which moves between positions spaced from and engaging the dielectric layer. At least one of the membrane and dielectric layer has a textured surface (138) that engages the other thereof in the actuated position. The textured surface reduces the area of physical contact through which electric charge from the membrane can tunnel into and become trapped within the dielectric layer. This reduces the amount of trapped charge that could act to latch the membrane in its actuated position, which in turn effects a significant increase in the operational lifetime of the switch.
    Type: Grant
    Filed: August 9, 2004
    Date of Patent: February 21, 2006
    Assignee: Raytheon Company
    Inventors: Brandon W. Pillans, David I. Forehand
  • Patent number: 6791441
    Abstract: A micro-electro-mechanical (MEMS) switch (10, 110) has an electrode (22, 122) covered by a dielectric layer (23, 123), and has a flexible conductive membrane (31, 131) which moves between positions spaced from and engaging the dielectric layer. At least one of the membrane and dielectric layer has a textured surface (138) that engages the other thereof in the actuated position. The textured surface reduces the area of physical contact through which electric charge from the membrane can tunnel into and become trapped within the dielectric layer. This reduces the amount of trapped charge that could act to latch the membrane in its actuated position, which in turn effects a significant increase in the operational lifetime of the switch.
    Type: Grant
    Filed: May 7, 2002
    Date of Patent: September 14, 2004
    Assignee: Raytheon Company
    Inventors: Brandon W. Pillans, David I. Forehand
  • Publication number: 20040124073
    Abstract: A micro-electro-mechanical (MEMS) switch (10, 110) has an electrode (22, 122) covered by a dielectric layer (23, 123), and has a flexible conductive membrane (31, 131) which moves between positions spaced from and engaging the dielectric layer. At least one of the membrane and dielectric layer has a textured surface (138) that engages the other thereof in the actuated position. The textured surface reduces the area of physical contact through which electric charge from the membrane can tunnel into and become trapped within the dielectric layer. This reduces the amount of trapped charge that could act to latch the membrane in its actuated position, which in turn effects a significant increase in the operational lifetime of the switch.
    Type: Application
    Filed: May 7, 2002
    Publication date: July 1, 2004
    Inventors: Brandon W. Pillans, David I. Forehand
  • Patent number: 6731420
    Abstract: An optical matrix switch station (1) is shown mounting a plurality of optical switch units (15, 17), each of which includes a mirror (29), moveable in two axes, for purpose of switching optical beams from one optical fiber to another. A mirror assembly (41) includes a single body of silicon comprising a frame portion (43), gimbals (45), mirror portion (47), and related hinges (55). Magnets (53, 54) and air coils (89) are utilized to position the central mirror surface (29) to a selected orientation. The moveable mirror and associated magnets along with control LED's (71) are hermetically packaged in a header (81) and mounted with the air coils on mounting bracket (85) to form a micromirror assembly package (99) mounted in each optical switch unit.
    Type: Grant
    Filed: November 8, 2002
    Date of Patent: May 4, 2004
    Assignee: Texas Instruments Incorporated
    Inventors: John W. Orcutt, Andrew S. Dewa, Herzel Laor, David I. Forehand, James A. Sisco
  • Publication number: 20030164997
    Abstract: An optical matrix switch station (1) is shown mounting a plurality of optical switch units (15, 17), each of which includes a mirror (29), moveable in two axes, for purpose of switching optical beams from one optical fiber to another. A mirror assembly (41) includes a single body of silicon comprising a frame portion (43), gimbals (45), mirror portion (47), and related hinges (55). Magnets (53, 54) and air coils (89) are utilized to position the central mirror surface (29) to a selected orientation. The moveable mirror and associated magnets along with control LED's (71) are hermetically packaged in a header (81) and mounted with the air coils on mounting bracket (85) to form a micromirror assembly package (99) mounted in each optical switch unit.
    Type: Application
    Filed: November 8, 2002
    Publication date: September 4, 2003
    Inventors: John W. Orcutt, Andrew S. Dewa, Herzel Laor, David I. Forehand, James A. Sisco
  • Publication number: 20020018615
    Abstract: An optical matrix switch station (1) is shown mounting a plurality of optical switch units (15, 17), each of which includes a mirror (29), moveable in two axes, for purpose of switching optical beams from one optical fiber to another. A mirror assembly (41) includes a single body of silicon comprising a frame portion (43), gimbals (45), mirror portion (47), and related hinges (55). Magnets (53, 54) and air coils (89) are utilized to position the central mirror surface (29) to a selected orientation. The moveable mirror and associated magnets along with control LED's (71) are hermetically packaged in a header (81) and mounted with the air coils on mounting bracket (85) to form a micromirror assembly package (99) mounted in each optical switch unit.
    Type: Application
    Filed: September 21, 2001
    Publication date: February 14, 2002
    Inventors: Herzel Laor, Philip A. Congdon, Andrew S. Dewa, David I. Forehand, Tsen-Hwang Lin, John W. Orcutt, James A. Sisco
  • Patent number: 6295154
    Abstract: An optical matrix switch station (1) is shown mounting a plurality of optical switch units (15, 17), each of which includes a mirror (29), moveable in two axes, for purpose of switching optical beams from one optical fiber to another. A mirror assembly (41) includes a single body of silicon comprising a frame portion (43), gimbals (45), mirror portion (47), and related hinges (55). Magnets (53, 54) and air coils (89) are utilized to position the central mirror surface (29) to a selected orientation. The moveable mirror and associated magnets along with control LED's (71) are hermetically packaged in a header (81) and mounted with the air coils on mounting bracket (85) to form a micromirror assembly package (99) mounted in each optical switch unit.
    Type: Grant
    Filed: May 12, 1999
    Date of Patent: September 25, 2001
    Assignee: Texas Instruments Incorporated
    Inventors: Herzel Laor, Philip A. Congdon, Andrew S. Dewa, David I. Forehand, Tsen-Hwang Lin, John W. Orcutt, James A. Sisco
  • Patent number: 5665998
    Abstract: A substantial portion of the material at the pn junction (27) of the photodiode (37, 41) having an implanted region extending to a surface thereof is selectively removed (39), leaving a very small junction region (35, 43) with the remainder of the p-type (23) and n-type (25) material of each photodiode being spaced apart or electrically isolated at what was originally the junction. In the ion implanted n-type on p-type approach, the majority of the signal is created in the implanted n-type region while the majority of the noise is generated in the p-type region. By selectively removing p-type material, n-type material or both from the pn junction of the diode or otherwise electrically isolating most of the p-type and n-type regions from each other at the pn junction and thereby minimizing the pn junction area, noise is greatly reduced without affecting the signal response of the photodiode.
    Type: Grant
    Filed: February 14, 1996
    Date of Patent: September 9, 1997
    Assignee: Texas Instruments Incorporated
    Inventors: Peter D. Dreiske, Arthur M. Turner, David I. Forehand
  • Patent number: 5593902
    Abstract: A substantial portion of the material at the pn junction (27) of the photodiode (37, 41) having an implanted region extending to a surface thereof is selectively removed (39), leaving a very small junction region (35, 43) with the remainder of the p-type (23) and n-type (25) material of each photodiode being spaced apart or electrically isolated at what was originally the junction. In the ion implanted n-type on p-type approach, the majority of the signal is created in the implanted n-type region while the majority of the noise is generated in the p-type region. By selectively removing p-type material, n-type material or both from the pn junction of the diode or otherwise electrically isolating most of the p-type and n-type regions from each other at the pn junction and thereby minimizing the pn junction area, noise is greatly reduced without affecting the signal response of the photodiode.
    Type: Grant
    Filed: May 23, 1994
    Date of Patent: January 14, 1997
    Assignee: Texas Instruments Incorporated
    Inventors: Peter D. Dreiske, Arthur M. Turner, David I. Forehand
  • Patent number: 5462882
    Abstract: Only the areas of the CdTe/HgCdTe interface of a FPA detector circuit which is coupled by an epoxy to a silicon-based integrated circuit that require interdiffusing are heated to a sufficiently high temperature or have photons of light impinging thereon for a sufficient time to cause interdiffusion of the two layers by the travel of tellurium into the HgCdTe and the travel of mercury into the CdTe. The vast majority of the wafer is masked with an aluminum thin film to greatly reduce heat gain or photon transmission. An advantage of the process in accordance with the present invention is that only a very small fraction of the HgCdTe/epoxy/silicon-based integrated circuit wafer receives incoming energy during interdiffusion whereby problems caused by the differences in coefficient of thermal expansion between silicon and HgCdTe at the epoxy interface are minimized.
    Type: Grant
    Filed: October 31, 1994
    Date of Patent: October 31, 1995
    Assignee: Texas Instruments Incorporated
    Inventors: Michael F. Chisholm, David I. Forehand
  • Patent number: 5420445
    Abstract: Only the areas of the CdTe/HgCdTe interface of a FPA detector circuit which is coupled by an epoxy to a silicon-based integrated circuit that require interdiffusing are heated to a sufficiently high temperature or have photons of light impinging thereon for a sufficient time to cause interdiffusion of the two layers by the travel of tellurium into the HgCdTe and the travel of mercury into the CdTe. The vast majority of the wafer is masked with an aluminum thin film to greatly reduce heat gain or photon transmission. An advantage of the process in accordance with the present invention is that only a very small fraction of the HgCdTe/epoxy/silicon-based integrated circuit wafer receives incoming energy during interdiffusion whereby problems caused by the differences in coefficient of thermal expansion between silicon and HgCdTe at the epoxy interface are minimized.
    Type: Grant
    Filed: February 22, 1993
    Date of Patent: May 30, 1995
    Assignee: Texas Instruments Incorporated
    Inventors: Michael F. Chisholm, David I. Forehand