Patents by Inventor John R. Todd

John R. Todd 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: 4868889
    Abstract: The nonlinearity of the frequency response of a solid state power amplifier (SSPA) is obviated by effectively operating the SSPA at the 1 dB compression point, where the nonlinearity does not exist, and controllably reducing, downstream of the SSPA, the power output produced by the SSPA to the level required by the link. In particular, the output is reduced by controllably inserting a relatively thin tapered blade of ferrite material into a waveguide coupling section downstream of the SSPA. Preferably the ferrite material is comprised of a robust carbonyl steel of sufficient thickness to withstand the heat induced in the course of its absorbing microwave energy at the SSPA output, while being of a narrow or thin configuration and oriented for insertion into the absorbing section of waveguide so as to not effectively alter the characteristics of the signal profile of the electromagnetic wave.
    Type: Grant
    Filed: November 23, 1988
    Date of Patent: September 19, 1989
    Assignees: American Telephone and Telegraph Company, AT&T Bell Laboratories
    Inventors: William E. McGann, John R. Todd
  • Patent number: 4804970
    Abstract: A dielectric antenna lens for planar wavefront/focal point conversion is configured of a series of concentric rings, each of which is contoured from a rear face to inclined termination edges that are delimited by the functional performance of the lens and which assist in the manufacture of the lens. In addition, the bottom edge of each ring, rather than terminate at a cylindrical side wall of an adjacent ring, terminates at a flattened region between itself and the adjacent ring. This flattened region effectively eliminates the acute angle wedge between rings and, together with the inclined termination edges of the rings, serves to enable the lens to be easily manufactured, as by injection molding, with the flattened land portions and inclined termination edges making possible removal of the lens from the injection mold.As a further aspect of the present invention there is provided a multiple wavelength conversion arrangement employing the dielectric lens in combination with a wavelength selective (e.g.
    Type: Grant
    Filed: May 6, 1985
    Date of Patent: February 14, 1989
    Assignee: Harris Corp.
    Inventor: John R. Todd