A new approach to the design optimization of HEMT and HBT for maximum gain-bandwidth of MSM-based integrated photoreceiver and its noise performance at 1.55 μm
A new and simple approach has been proposed for the design optimization of devices using PSPICE, and it has been applied to the design of high electron mobility transistors (HEMTs) and heterojunction bipolar transistors (HBTs) for the maximum gain-bandwidth (GBW) of a front-end integrated photoreceiver that uses metal-semiconductor-metal (MSM) structure as the photodector at 1.55 mum, The standard high frequency circuit models are used with some important modifications to simplify the model equations. The results of the optimized design show that the gain-bandwidth of the photoreceiver can be raised to a very high value compared to those of nonoptimized structures. Finally, the sensitivity of the integrated photoreceivers are calculated for a bit-error-rate of 10(-9).