R.F. Diplexing and multiplexing means
First Claim
Patent Images
1. Apparatus comprising:
- a balun having an unbalanced port with first and second terminals, said first and second terminals having a winding therebetween, a balanced port with third and fourth terminals, said third and fourth terminals having a winding therebetween, and an impedance transformation circuit coupled between the unbalanced and balanced ports for coupling signals therebetween;
a point of reference potential;
first unbalanced circuit means referenced to said reference potential coupled to said first terminal of said unbalanced port;
second unbalanced circuit means referenced to said reference potential coupled to said second terminal of said unbalanced port;
balanced circuit means coupled between said third and fourth terminals of said balanced port;
first selection means for selectively coupling said first terminal of said unbalanced port to said point of reference potentential, thereby allowing signals to be coupled between said second terminal and said third and fourth terminals; and
second selection means for selectively coupling said second terminal of said unbalanced port to said point of reference potential, thereby allowing signals to be coupled between said first terminal and said third and fourth terminals.
2 Assignments
0 Petitions
Accused Products
Abstract
Selection elements such as diodes or filters are provided for selectively grounding either one of the two unbalanced terminals of a balun. This allows either a signal, such as the R.F. signals from a VHF or a UHF antenna, applied to the other unbalanced terminal of the balun to be selectively coupled to the balanced terminals of the balun in a diplexer arrangement. In a tuner, the balun may be used as part of a doubly balanced mixer. In another embodiment, the balanced terminals are used as inputs and the unbalanced terminals are used as outputs with the selection elements coupled to the outputs to form an R.F. multiplexer.
-
Citations
26 Claims
-
1. Apparatus comprising:
-
a balun having an unbalanced port with first and second terminals, said first and second terminals having a winding therebetween, a balanced port with third and fourth terminals, said third and fourth terminals having a winding therebetween, and an impedance transformation circuit coupled between the unbalanced and balanced ports for coupling signals therebetween; a point of reference potential; first unbalanced circuit means referenced to said reference potential coupled to said first terminal of said unbalanced port; second unbalanced circuit means referenced to said reference potential coupled to said second terminal of said unbalanced port; balanced circuit means coupled between said third and fourth terminals of said balanced port; first selection means for selectively coupling said first terminal of said unbalanced port to said point of reference potentential, thereby allowing signals to be coupled between said second terminal and said third and fourth terminals; and second selection means for selectively coupling said second terminal of said unbalanced port to said point of reference potential, thereby allowing signals to be coupled between said first terminal and said third and fourth terminals. - View Dependent Claims (2, 3, 4, 5)
-
-
6. Apparatus comprising:
-
a point of reference potential; a balun having first and second bifilar windings and third and fourth bifilar windings, each of said windings having first and second ends; said first ends of said first and third windings being coupled together to form a first terminal and said first ends of said second and fourth windings being coupled together to form a second terminal, said first and second terminals comprising an unbalanced port; said second ends of said second and third windings being coupled together and to said point of reference potential for radio frequency signals; said second ends of said first and fourth windings respectively comprising third and fourth terminals of a balanced port; first selection means for selectively coupling said first terminal of said unbalanced port to said point of reference potential, thereby allowing signals to be coupled between said second terminal and said third and fourth terminals; and second selection means for selectively coupling said second terminal of said unbalanced port to said point of reference potential thereby allowing signals to be coupled between said first terminal and said third and fourth terminals. - View Dependent Claims (7, 8, 9, 10)
-
-
11. Apparatus comprising:
-
a balun having unbalanced and balanced ports, said unbalanced port including first and second terminals having a winding therebetween; and means for selectively grounding either of said terminals, thereby allowing signals to be coupled between the other of said terminals and said balanced port. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18, 19)
-
-
20. Apparatus comprising:
-
VHF and UHF signal sources; a first balun having unbalanced and balanced ports, said unbalanced port having a pair of terminals respectively coupled to said sources; means for selectively grounding a selected one of said terminals; a mixer coupled to said balanced port; a second balun having an unbalanced port and a balanced port coupled to said mixer; and a local oscillator coupled to said second balun unbalanced port. - View Dependent Claims (21, 22, 23, 24)
-
-
25. Apparatus comprising:
- a balanced signal source;
a balun having a balanced port coupled to said source and an unbalanced port having a pair of terminals adapted to be respectively coupled to a pair of loads;
a pair of switching means respectively coupled to said terminals for grounding either one of said terminals whereby said source is selectively coupled to the other one of said loads.
- a balanced signal source;
-
26. Apparatus comprising:
- a pair of unbalanced signal sources;
a balun having a balanced port adapted to be coupled to a load and an unbalanced port having a pair of terminals, said terminals having a winding therebetween;
a pair of switching means respectively coupled to said signal sources and said terminals for selectively grounding either one of said terminals for selectively coupling the other terminal to said load.
- a pair of unbalanced signal sources;
Specification