Apparatus for combining broadband and baseband signal transmissions

• US 5,255,267 A
• Filed: 03/09/1992
• Issued: 10/19/1993
• Est. Priority Date: 03/09/1992
• Status: Expired due to Fees

• Current Assignee: Future Technology Incorporated (Advanced Power Electronics Corp.)
• Original Assignee: First Pacific Networks, Inc.
• Inventors: Hansen, David E., Phan, Chinh Q., Serrone, Michael J., McNamara, Robert P.
• Primary Examiner(s): Olms, Douglas W.
• Assistant Examiner(s): BLUM, RUSSELL
• Application Number:
  US07/848,570
• Time in Patent Office: 589 Days
• Field of Search: 370/85.1, 370/85.3, 370/124, 370/123
• US Class Current: 370/401
• CPC Class Codes: H04L 12/66 Arrangements for connecting between networks having differing types of switching systems, e.g. gateways
• CPC Class Codes: Y10S 370/908 Local area network

Abstract

Apparatus for combining broadband RF signals and baseband signals in a baseband distribution cable includes a bridge for coupling the distribution cable to an RF broadband trunk and to a baseband repeater. The trunk is connected through bidirectional amplifier, an impedance transformer, and a signal splitter for applying the amplified and impedance transformed broadband signal to a plurality of baseband segments. The RF signal from the splitter is passed through a 35 MHz high pass filter to the baseband segment. Baseband signals from a repeater are passed through a 25 MHz low pass filter to the baseband segment. The two filters prevent interference between the baseband and broadband signals. A tap in the distribution cable for accessing the broadband and baseband signals includes first and second low pass filters and a directional coupler serially connected between two cable terminals with a high pass filter connected in parallel with a first and second low pass filters whereby broadband signals can pass around the low pass filters. A third low pass filter connects an MAU port to the first and second low pass filters whereby baseband signals can be transmitted in either direction on the distribution cable without injecting noise in the broadband signal.

Claims

1. A distribution network for RF broadband signals and baseband signals comprising:

a distribution cable;

a repeater low pass filter for connecting said distribution cable to a baseband signal;

a trunk high pass filter for connecting said distribution cable to a broadband signal; and

at least one tap in said cable including first and second terminals serially connected to said cable;

a first low pass filter, a second low pass filter, and a directional coupler serially connected between said first and second terminals;

a first high pass filter connected in parallel with said first and second low pass filters for passing broadband signals around said low pass filters, an MAU port and low pass filter connecting said MAU port to a common terminal of said first and second low pass filters, and a broadband port connected to said directional coupler.

2. The distribution network as defined by claim 1 and further including a first impedance transformer and a signal splitter for serially connecting a broadband signal to said trunk high pass filter.

3. The distribution network defined by claim 2 wherein each low pass filter filters out signals above 25 MHz and each high pass filter filters out signals below 35 MHz.

4. The distribution network as defined by claim 1 and further including a second tap for terminating an RF broadband signal in said cable, said second tap including a third terminal, a broadband tap, and a second impedance transformer and a second high pass filter serially connected between said broadband tap and said third terminal.

5. The distribution network as defined by claim 4 wherein said second tap further includes a baseband terminal, and a fourth low pass filter connected between said third terminal and said baseband second terminal for transmitting baseband signals in said cable.

6. A tap for accessing an RF broadband signal and a baseband signal in a cable comprising:

first and second terminals for connecting to said cable,

a first low pass filter, a second low pass filter, and a directional coupler serially connected between said first and second terminals,

a first high pass filter connected in parallel with said first and second low pass filters for passing broadband signals around said low pass filters,

a third low pass filter connecting an MAU port to said first and second low pass filters, and

a broadband port connected to said directional coupler.

7. The tap as defined by claim 6 wherein each low pass filter filters out signals about 25 MHz and said high pass filter filters out signals below 35 MHz.

8. The tap as defined by claim 6 wherein said first and second filters comprise 25 MHz low pass filters, said high pass filter comprises a 35 MHz high pass filter and said third low pass filter comprises a 54 MHz low pass filter.