Patents Assigned to AT&T Bell Telephone Laboratories, Incorporated
  • Patent number: 4467344
    Abstract: A semiconductor structure contains two interconnected gated diode switches in a common dielectrically isolated semiconductor tub. This structure functions as a bidirectional switch. A gate region physically located between the two switches provides electrical isolation to allow proper operation.
    Type: Grant
    Filed: December 23, 1981
    Date of Patent: August 21, 1984
    Assignee: AT&T Bell Telephone Laboratories, Incorporated
    Inventors: Gee-Kung Chang, Adrian R. Hartman, Harry T. Weston
  • Patent number: 4466060
    Abstract: An adaptive distributed message routing algorithm that may be implemented in a computer program to control the routing of data messages in a packet message switching digital computer network. Network topology information is exchanged only between neighbor nodes in the form of minimum spanning trees, referred to as exclusionary trees. An exclusionary tree is formed by excluding the neighbor node and its links from the tree. From the set of exclusionary trees received a route table and transmitted exclusionary trees are constructed.
    Type: Grant
    Filed: February 11, 1982
    Date of Patent: August 14, 1984
    Assignee: AT&T Bell Telephone Laboratories, Incorporated
    Inventor: Guy G. Riddle
  • Patent number: 4443809
    Abstract: Photodiodes (10) are fabricated in a single step diffusion process which exploits the characteristic of certain acceptors to form an anomalous diffusion profile (VI) including shallow and deep fronts (VIa and b) joined by an upwardly concave segment (VIc). By performing this type of diffusion into a low-doped n.sup.- -type body (12) with a carrier concentration (VII) below that of the concave segment, a p.sup.+ -p.sup.- junction (15) is formed at the depth of the concave segment and a p.sup.- -n.sup.- junction (17) is formed at a greater depth. The zone (16) between the junctions is at least partially depleted and forms the active region of a p.sup.+ -p.sup.- -n.sup.- photodiode. Specifically described are InP:Cd photodiodes.
    Type: Grant
    Filed: July 29, 1982
    Date of Patent: April 17, 1984
    Assignee: AT & T Bell Telephone Laboratories, Incorporated
    Inventors: Aland K. Chin, Bulusu V. Dutt
  • Patent number: 4442529
    Abstract: In a conventional CMOS integrated circuit such as a switched capacitor filter, power supply noise signals are coupled from the substrate to high impedance nodes via various parasitic capacitances. To minimize these noise signals and thereby improve the power supply rejection ratio of the circuit, only N-channel transistors are coupled to the nodes. Additionally, the P-tubs of these transistors are connected to an on-chip regulated power supply. Moreover, for certain metallic runners and capacitors of the circuit that are connected to the specified nodes and parasitically coupled to the substrate, grounded P-tubs are formed directly under the runners and capacitors.
    Type: Grant
    Filed: February 4, 1981
    Date of Patent: April 10, 1984
    Assignee: AT&T Bell Telephone Laboratories, Incorporated
    Inventors: Bhupendra K. Ahuja, Mirmira R. Dwarakanath