Patents by Inventor Lothar Friederichs

Lothar Friederichs 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).

  • Frequency-channel multiplexer and demultiplexer
    Patent number: 5691987
    Abstract: A circuit of low complexity which selects arbitrary channels from a plurality of multichannel input signals and generates from a plurality of individual frequency channels a plurality of output signals whose channel composition can be freely selected, consists of a plurality of bandpass filters (BP1, BP2 . . . BPn) which are tuned to the individual frequency channels and whose input and output are respectively connected to a gate of one of a plurality of circulators (Z11, Z12 . . . Z1n; Z21, Z22 . . . Z2n) connected in a chain. In this case, at least two circulator chains are present (ZK1, ZK2), and a circulator (Z11, Z12 . . . Z1n; Z21, Z22 . . . Z2n) from one of the circulator chains can be optionally switched to the input and output of each bandpass filter (BP1, BP2 . . . BPn).
    Type: Grant
    Filed: March 8, 1995
    Date of Patent: November 25, 1997
    Assignee: ANT Nachrichtentechnik GmbH
    Inventor: Lothar Friederichs