CROSSTALK CHARACTERISTIC OF MONOLITHICALLY INTEGRATED RECEIVER ARRAYS

The crosstalk characteristics of a long-wavelength monolithically inte grated photoreceiver array are analyzed. The device consists of an arr ay of transimpedance photoreceivers fabricated on a semi-insulating In P substrate. The distance between the photodetectors is large enough t o suppress the photonic crosstalk. Therefore, the crosstalk of the dev ice is mainly due to signal propagation from the channels through the power line shared by each channel on the chip. This crosstalk is inevi table to the photoreceiver arrays which employ common power lines. The magnitude of the crosstalk largely depends on the impedance of the po wer-supply circuit outside the chip. The crosstalk spectrum often has a peak and recess structure. The crosstalk peak al the edge of the ope rating band-width is due to the resonance characteristic of the transi mpedance amplifier. The other peak and recess structures on the spectr um are due to the resonance phenomena of on-chip and off-chip capacito rs and inductance on the power-supply line outside the chip. This cros stalk can be reduced by using on-chip bypass capacitance and dumping r esistance. However, the resonance due to the capacitance and inductanc e on the power-supply circuit outside the chip can't be controlled by the on-chip components. Therefore, an optimized design for the power s upply circuit outside the chip is also indispensable for suppressing c rosstalk.