Hybrid circuit for a broadband modem

A hybrid circuit for coupling a broadband modem to a telecommunication line, said hybrid circuit comprising a transformer bridge circuit including a bridge circuit coupled between a drive amplifier and a receive amplifier such that said drive amplifier provides an output signal derived from a transmit signal received from said modem and said receive amplifier provides a receive output signal to be applied to said modem, said transformer bridge circuit further including a transformer having a secondary winding electrically coupled to said telecommunication line,

• said bridge circuit comprising first, second, third and fourth nodes interconnected via first through fourth legs, the first leg comprising a first impedance matching network coupled across said second and third nodes, the second leg comprising a first primary winding of said transformer coupled across said first and third nodes, the third leg comprising a second impedance matching network coupled across said first and fourth nodes, and the fourth leg comprising a second primary winding of said transformer coupled across said second and fourth nodes, the secondary winding of said transformer being magnetically coupled to said first and second primary windings,
• wherein said drive amplifier is a differential drive amplifier having feedback inputs and being adapted to perform impedance synthesis,
• wherein said third and fourth nodes are respectively connected to a first and to a second of said feedback inputs,
• and wherein said bridge circuit further comprises
• a first impedance divider coupled between said first and third nodes, and having a first central node to which a first input of said receive amplifier is connected, and
• a second impedance divider coupled between said second and fourth nodes, and having a second central node to which a second input of said receive amplifier is connected.