Telecommunications – Receiver or analog modulated signal frequency converter – Frequency modifying or conversion
Patent
1995-12-18
1998-05-12
Urban, Edward F.
Telecommunications
Receiver or analog modulated signal frequency converter
Frequency modifying or conversion
455333, 327113, 333119, H04B 126
Patent
active
057521816
ABSTRACT:
Apparatus for reducing intermodulation distortion in a mixer output signal provides for back-to-back serial connected FET transistors joined at gate and source terminals and cancels intermodulation distortion. In one embodiment the apparatus provides first and second FET having their gates tied to one another and their sources tied to one another such that the FETs are connected back-to-back in series and have equal gate-to-source voltages and FET drain-to-source voltage that are equal in magnitude but opposite in sign to the second FET drain-to-source voltage. A control voltage, such as a local oscillator voltage signal is applied between the FET gate terminals and the FET source terminals to switch the conduction state of the serially connected FETs between a conducting state and a non-conducting state. A second signal, such as either an RF or an IF signal, is applied between the drain terminals of the FETs and this second signal passes through a channel combination defined by the serially connected FETs during channel conduction, and thus mixes with the control signal to generate the mixer output signal. Intermodulation distortion is introduced into the output signal by the first and second FET, but the structure and method provide for suppression or substantial cancellation of this intermodulation distortion in the final mixer output signal. Embodiments having a duplicity of serially connected FET pairs are also provided.
REFERENCES:
patent: 4675911 (1987-06-01), Sokolov et al.
patent: 4979233 (1990-12-01), Kawahata
patent: 5060298 (1991-10-01), Waugh et al.
patent: 5280648 (1994-01-01), Dobrovolny
patent: 5361409 (1994-11-01), Vice
Ananian R. Michael
Urban Edward F.
Watkins-Johnson Company
LandOfFree
Method and apparatus for reducing inermodulation distortion in a does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method and apparatus for reducing inermodulation distortion in a, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method and apparatus for reducing inermodulation distortion in a will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-996038