Invalidity dossier
US 5504745
Switching cell transmission device employing dual gate FET's as one-way RF switching element
Current assignee: European Space Agency
Added 9/23/2026, 5:53:06 PM
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Patent summary
Title, assignee, inventors, filing/issue dates, abstract, and a plain-language overview of the claims.
Patent Overview — US 5,504,745
Title: Switching cell transmission device employing dual gate FET's as one-way RF switching element
Patent Number: US5504745A
Application Number: US08/251,942
Inventors: Felix A. Petz; Wolfgang Greiner
Assignee: Agence Spatiale Europeenne (original and current assignee per source)
Priority/Filing Date: 1994-06-01 (also priority to FR9406688A)
Grant/Publication Date: 1996-04-02
Legal Status: Expired – Fee Related; anticipated expiration 2014-06-01
Classification: H03K17/687; H03K17/693 (electronic switching using field-effect transistors; multiplexers/distributors)
Purpose: The invention relates mainly to distribution and/or processing devices for radiofrequency (RF) signals—including signal combiners, splitters/dividers, time and frequency multiplexers/demultiplexers, amplifiers, attenuators, variable delay lines, and vector-modulator-type signal shaping circuits. Its stated objects are large bandwidth, high speed, compactness, low electricity consumption, low losses/attenuation, and both-way operation.
Plain-language scope: The device comprises a plurality of inlets and/or outlets, a plurality of switching cells each including a one-way RF switching element that interconnects input(s) to output(s) on command, and a simultaneous and/or sequential control circuit controlling the ON/OFF states of the switching elements to set up a desired RF signal distribution or processing. The switching elements are preferably dual gate FETs. In the preferred matrix embodiment (FIG. 1), m input lines and n output lines are arranged orthogonally, each line including series inductors forming delay lines, with each dual-gate FET coupling an input line to an output line; gate G1 connects to the input line, the drain to the output line, gate G2 receives a control voltage, and the source connects to ground.
Stated prior art reference: U.S. Pat. No. 4,983,865 (switching matrix for RF signals using dual gate FETs).
Source: https://patents.google.com/patent/US5504745/en
What the excerpt does not establish: Full claim language, complete description, all drawing details, the full FR2720882A1 relationship, or the actual legal scope/validity of the claims. The excerpt is partial; omitted text should be consulted. No litigation, ownership-transfer, or validity conclusions are drawn here.
Generated 10/1/2026, 9:43:14 PM
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Assignment history
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Prior art
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Obviousness
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Derivative works
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