Design and Layout of a Transimpedance Amplifier (tia) at 50 GHz for Optical Receivers in ihp 130nm SiGe BiCMOS Technology

Today’s technology allows for a quick and efficient transmission of enormous amounts of data. Optical fibres are currently the most effective way to transmit enormous amounts of data. A photodiode (PD) generates current from the optical fibre’s light to receive the data transmitted. However, this current is very small. It is necessary to use an amplifier that, in addition to amplifying the photodiode current, also converts it into a voltage for the optical receiver’s subsequent phases. These
amplifiers also referred to as transimpedance amplifiers, are an essential component of optical receivers because they must have a high gain to amplify the photodiode current and a large bandwidth to pick up high data rate signals. This thesis thoroughly analyses these amplifiers, outlining the advantages and disadvantages of various topologies. This thesis uses mathematical equations to describe the operation of the Transimpedance Amplifier (TIA) and to identify the optimal range between the gain, the bandwidth, and the noise (input-referred noise) to produce the amplifier with the desired characteristics. Electrical simulations were used to test all the theoretical assertions and the entire system’s behaviour for
the four topologies of the common base, common emitter, regulated cascode, and darlington pair. The minimum transimpedance gain target for the TIA is 60 dBΩ with a minimum bandwidth of 40 GHz. The designed TIA should have an input-referred noise of less than 20 pA/√Hz. After thoroughly examining these four topologies, a layout is designed for darlington pair TIA with resistive feedback. The implemented TIA has achieved a transimpedance gain of 63.74 dBΩ with a broad bandwidth of 60.84 GHz. The designed TIA has achieved a low input-referred noise of 16.20 pA/√Hz. The designed TIA has a chip size of just 0.0064 mm2 and uses 30.53 mW of DC power.