Invention Grant
- Patent Title: DC current cancellation scheme for an optical receiver
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Application No.: US15833314Application Date: 2017-12-06
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Publication No.: US10944486B2Publication Date: 2021-03-09
- Inventor: Mostafa Ahmed , Alexander Rylyakov
- Applicant: Elenion Technologies, LLC
- Applicant Address: US NY New York
- Assignee: Elenion Technologies, LLC
- Current Assignee: Elenion Technologies, LLC
- Current Assignee Address: US NY New York
- Agency: Stratford Managers Corporation
- Main IPC: H04B10/60
- IPC: H04B10/60 ; H04B10/69 ; H04B10/67 ; H03F1/00 ; H03F3/00

Abstract:
In high data rate receivers, comprising a photodetector (PD) and a transimpedance amplifier (TIA), a transmitted optical signal typically has poor extinction ratio, which translates into a small modulated current with a large DC current at the output of the PD. The large DC current saturates the TIA, which significantly degrades the gain and bandwidth performance. Accordingly, cancelling photo diode DC current in high data rate receivers is important for proper receiver operation. A DC current cancellation loop, comprising a low pass filter section and a trans-conductance cell (GM) are connected to the input of the TIA. PD DC current IDC is drawn from the input node of the TIA in the GM cell, such that the cancellation loop maintains the DC voltage value of the TIA input node to be the same as a reference voltage (VREF).
Public/Granted literature
- US20190173588A1 DC CURRENT CANCELLATION SCHEME FOR AN OPTICAL RECEIVER Public/Granted day:2019-06-06
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