Signal coupler with automatic common line attenuation compensation
First Claim
1. Signal coupler including a first branch (ATR, HPF) for transmission and receipt of a first signal and a second branch (PTR, SL, LPF) for transmission and receipt of a second signal, said first and second branches both being coupled to a common transmission line (TL), said first signal having a first frequency spectrum and said second signal having a second frequency spectrum, said first and second frequency spectra being non-overlapping, said first branch including the cascade coupling of a first signal means (ATR) and a first bandpass filter (HPF) both adapted to said first frequency spectrum, said second branch including the cascade coupling of a second signal means (PTR) and a second bandpass filter (LPF) both adapted to said second frequency spectrum, wherein said second branch includes a variable impedance (SL) and said first signal means (ATR) includes measurement means (MM) to measure attenuation caused by said common line (TL) and to generate a control signal (CS) adapted to modify the value of said variable impedance (SL).
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Accused Products
Abstract
The present invention relates to a for coupling Plain Old Telephone Service (POTS) signals and Asymmetric Digital Subscriber Line (ADSL) signals to a common line (TL). In order to avoid saturation of inductances (L1,L2,L3,L4) of a low pass POTS filter (LPF) located between the POTS transmitter/receiver (PTR) and this common line (TL) when the POTS signal is not sufficiently attenuated by this common line (TL), a variable impedance (SL) is inserted between the POTS transmitter/receiver (PTR) and this low pass POTS filter (LPF). The value of this variable impedance (SL) is controlled by a control signal (CS) supplied by the ADSL transmitter/receiver (ATR) which measures the attenuation caused by this common line (TL).
140 Citations
9 Claims
- 1. Signal coupler including a first branch (ATR, HPF) for transmission and receipt of a first signal and a second branch (PTR, SL, LPF) for transmission and receipt of a second signal, said first and second branches both being coupled to a common transmission line (TL), said first signal having a first frequency spectrum and said second signal having a second frequency spectrum, said first and second frequency spectra being non-overlapping, said first branch including the cascade coupling of a first signal means (ATR) and a first bandpass filter (HPF) both adapted to said first frequency spectrum, said second branch including the cascade coupling of a second signal means (PTR) and a second bandpass filter (LPF) both adapted to said second frequency spectrum, wherein said second branch includes a variable impedance (SL) and said first signal means (ATR) includes measurement means (MM) to measure attenuation caused by said common line (TL) and to generate a control signal (CS) adapted to modify the value of said variable impedance (SL).
Specification