High bandwidth transimpedance amplifier with a miniaturized package for high speed opto-electrical interconnection

The package design and development of a high bandwidth (BW) transimpedance amplifier (TIA) is investigated in this paper. The packaged 54 GHz TIA is used and demonstrated in a high speed opto-electrical interconnection for a system-level solution with high performance and clean eye diagram to ensure a good data transmission quality with low bit error rate (BER), which is integrated in a compact size and verified by the experimental results. The package integrates a TIA die, tapered low-loss transmission lines (TMLs), bonding wires as well as high BW coaxial connectors (SMA). Multi-layer low temperature co-fired ceramic (LTCC) substrate is one of the best candidates for radio frequency (RF) system-level integration due to its advantages of low loss, high integration capability and reasonably low cost, which is applied to realize compact TMLs, transforming the signal path from pad pitch of the TIA die to the footprint of the SMA. The gain, BW and return loss of the TIA die is probe measured on chip, in order to characterize the performance of TIA and to evaluate the high speed transient opto-electrical data interconnection in time-domain. In addition, the electrical model of passive components, such as: co-planar waveguide (CPW), bonding wires and SMA connectors, have been respectively created and combined, in order to achieve an overall test-bench for the TIA package. The choice of the packaging method and the in-package TML structure is crucial to ensure a good RF performance. Both wire-bonding and flip-chip technique are commonly utilized in the high BW package prototype for high speed opto-electrical interconnection, and finally bonding wires have been applied and integrated in the TIA package due to its advantages of accurate electrical model and low fabrication cost. Both simulation and measurement results of the TIA die and packaged TIA are characterized and compared, in both frequency and time domain with the data rate up to 30 Gbit/s, in order to validate the high BW package design flow and high speed data interconnection application.