Bandwidth extension circuit of cascode trans-impedance amplifier based on CMOS (complementary metal oxide transistor) technology

Abstract

The invention discloses a bandwidth extension circuit of a cascode trans-impedance amplifier based on CMOS (complementary metal oxide transistor) technology. The bandwidth extension circuit is of completely bilaterally symmetric structure; each of the left and right parts of the bandwidth extension circuit includes a traditional primary cathode-input amplifier, a novel cascode auxiliary amplifierand a terminal source follower; the novel cascode structure is used herein to assist the amplifiers in shielding Miller effect; the concurrent PMOS (P-channel metal oxide semiconductor) structure provides greater transconductance for the cathode-input NMOS (N-channel metal oxide semiconductor); stray capacitance is partially shielded with a Pi-shaped matching network shielding portion; the terminal source follower is added to isolate stray post-capacitance, and total bandwidth of the circuit herein is increased; the circuit herein helps effectively reduce input impedance via RGC structure, andinput capacitance that is mainly of photoelectric detector junction capacitance is better isolated; the circuit herein gains adjustment and optimization for component parameters; differential structure is utilized so that working bandwidth of the circuit herein is greatly widened.

Description

technical field [0001] The invention relates to the fields of optical communication, optical interconnection and visible light communication, in particular to a series of new methods for extending the bandwidth of cascode transimpedance amplifiers. Background technique [0002] The advent of the big data era has accelerated the demand for broadband network development, and the rapid growth of traffic means that optical fiber transmission systems with higher speeds and wider frequency bands are required. Traditional copper interconnection is limited by factors such as crosstalk and loss, and it has been difficult to adapt to ultra-high-speed data transmission and exchange. However, the optical interconnect technology, which uses light as the carrier of information transmission, has many advantages such as low high-frequency loss, low crosstalk noise, and wide operating frequency bandwidth. Although HBT / HEMT (Heterojunction Bipolar Transistor / High Electron Mobility Field Effe...

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Problems solved by technology

[0004] Although the transimpedance amplifier based on the classic RGC structure of the standard CMOS process has obtained gigahertz bandwidth, the input parasitic capacitance mainly composed of the junction capacitance of the photodetector and the parasitic effect of the post-stage capacitance still have a great influence on the overall bandwidth of the amplifier. It is difficult to meet the increasing bandwidth demand

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