Larry D Alter

US Patent:

43408729, Jul 20, 1982

Filed:

Nov 26, 1980

Appl. No.:

6/210630

Inventors:

Larry D. Alter - Treasure Island FL

Assignee:

E-Systems, Inc. - Dallas TX

International Classification:

H03H 942
H03H 968
H03H 938

US Classification:

333152

Abstract:

A continuously variable delay line (10) includes a piezoelectric crystal (12) having an input transducer (14) and an output transducer (16). An input signal is transmitted through input lines (18) to the input transducer (14) and received through output lines (20) from the output transducer (16). The input signal is converted to a surface acoustic wave for transmission across the surface of crystal (12). Control electrodes (22 and 24) are applied to surfaces of the crystal (12) and are connected to control lines (26). A control signal is applied to the control lines (26) to apply an electric field to the crystal (12). The electric field thus applied alters the longitudinal dimensional characteristic of the crystal (12) and thereby controls the propagation distance between the input transducer (14) and the output transducer (16). By varying the propagation distance between the transducers (14, 16) the control signal continuously varies the propagation delay of a signal as it is transmitted across the surface of the crystal (12). Thus, the time delay between the input and output lines is a function of the control signal applied to lines (26).

US Patent:

43476279, Aug 31, 1982

Filed:

Feb 26, 1979

Appl. No.:

6/015232

Inventors:

Larry D. Alter - Treasure Island FL

Assignee:

E-Systems, Inc. - Dallas TX

International Classification:

H04B 708

US Classification:

455136

Abstract:

A processing circuit (50) in a communication system performs multi-channel adaptive array processing using a summed reference technique. A plurality of adaptive modules (56 and 58) modify the magnitude and phase of antenna element signals from a plurality of antenna elements. The outputs of the adaptive modules are combined by a combiner (60) to produce a summation signal. A modem (64) processes and divides the summation signal into a plurality of reference channel signals on channels 1 through K. A summer (70) adds the reference channel signals together to produce a composite reference signal that is subtracted by a subtractor (74) from the summation signal to produce an error signal. The error signal is applied to the adaptive modules (56 and 58) which respond to nullify interfering and noise signals and to enhance the signal-to-interference ratio for the summation signal.