Abstract: A method and apparatus for filtering interference signals to and from a broadband over power line system. The apparatus includes fixed notch filters and adaptive notch filters that filter interference signals that are generated and received by the system. The fixed filters are used for known interference signals, and the adaptive notch filters are used to filter unknown interference signals that are detected over time. The notch filters are configured at both a bridge and client of the system that send and receive broadband signals.

Abstract: A method for weld repairing airfoils made from nickel based super alloy material is provided. The method includes removing a damaged portion of the airfoil by machining the airfoil to a relatively smooth surface. Powdered alloy material, such as IN-100 material is then fed to a plasma arc welding device. A plurality of weld beads are deposited along the damaged portion of the airfoil in a continuous bi-directional pattern by the welding device to eliminate abrupt thermal transients at the ends of the weld, thereby reducing the thermal stresses that cause cracking in susceptible alloys such as IN-100.

Abstract: A feed forward amplifier network (100) employs a method (300) and apparatus for providing carrier cancellation in a feed forward amplifier circuit (101). A modulator (118, 120) modulates (303) an input signal (141) of the amplifier circuit (101) with a reference modulation based on a reference signal (143, 145) and a control signal (153, 155). The amplifier circuit (101) amplifies (305) the modulated signal, introducing nonlinear distortion in the process. A modulation determination circuit (107, 109, 115) determines (307) the reference modulation in the amplified signal and provides a determined signal to an adjustment circuit (105). A residual modulation detection circuit (139, 125, 127, 129) demodulates (313) the determined modulation to recover any residual modulation remaining in the determined signal and adjusts (317) the control signal (153, 155) to reduce the recovered residual modulation and to produce carrier cancellation in the determined signal.