Wave transmission lines and networks – Coupling networks – Balanced to unbalanced circuits
Patent
1997-05-23
2000-11-21
Pascal, Robert
Wave transmission lines and networks
Coupling networks
Balanced to unbalanced circuits
333 32, H03H 742
Patent
active
061508969
ABSTRACT:
Disclosed is a passive, highly efficient, low noise coupling device that includes a balun and noise reduction circuitry uniquely configured for converting an unbalanced video signal on a 75 ohm transmission line or connector to a balanced signal on a 100 ohm transmission line or connector and vice versa. The device efficiently allows use of a 100 ohm unshielded twisted pair, such as a conventional telephone cable, for multiplex transmission of video signals or the like in the frequency range of 50 to 500 megahertz. The preferred embodiment has a circuit board with a 75 ohm unbalanced side and a 100 ohm balanced side separated by a balun having a toroid core with a very high permeability. A common mode choke for noise rejection is inserted in the balanced side. A common mode toroid shunt on the device's balanced side provides further noise reduction. An isolation transformer in the device can provide personnel protection and eliminate ground loops. Circuit board traces connecting the components are impedance matched to either the balanced side or the unbalanced side as appropriate.
REFERENCES:
patent: 1812624 (1931-06-01), Cummings
patent: 3223920 (1965-12-01), Sasaki
patent: 3311831 (1967-03-01), Leppert
patent: 3352966 (1967-11-01), Sawazaki et al.
patent: 4037177 (1977-07-01), Tyrey
patent: 4201960 (1980-05-01), Skutta
patent: 4201962 (1980-05-01), Hosoya
patent: 4670874 (1987-06-01), Sato et al.
patent: 4717896 (1988-01-01), Graham
patent: 4766402 (1988-08-01), Crane
patent: 4885747 (1989-12-01), Foglia
patent: 5010399 (1991-04-01), Goodman et al.
patent: 5027426 (1991-06-01), Chiocca, Jr.
patent: 5126702 (1992-06-01), Gris
patent: 5170493 (1992-12-01), Roth
patent: 5200718 (1993-04-01), Kato
patent: 5283637 (1994-02-01), Goolcharan
patent: 5420551 (1995-05-01), Conte et al.
Decramer John E.
Gass Franklin Bradley
BH Electronics, Inc.
Pascal Robert
LandOfFree
Coupling device connecting an unbalanced signal line to a balanc does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Coupling device connecting an unbalanced signal line to a balanc, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Coupling device connecting an unbalanced signal line to a balanc will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1261428