Title :
A 5Gb/s 7-channel current-mode imaging receiver front-end for free-space optical MIMO
Author :
Zeng, Juan ; Joyner, Valencia ; Liao, Jun ; Deng, Shengling ; Huang, Zhaoran
Author_Institution :
Dept. of Electr. & Comput. Eng., Tufts Univ., Medford, MA, USA
Abstract :
A 7-channel diversity receiver front-end based on current-summing for broadband free-space optical (FSO) MIMO communication is presented in this paper. This diversity receiver is designed for flip-chip bonding to a custom InGaAs metal-semiconductor-metal (MSM) photodetector array. Each channel employs a low input-impedance current mirror (CM) as the input stage, which allows the implementation of direct current-summing for equal-gain combining (EGC). The summed-up current signal drives a second stage transimpedance amplifier (TIA) to generate the output voltage. Implemented in an 180 nm CMOS technology, a total gain of 58.5 dBOmega, and -3 dB bandwidth of 3.7 GHz for 0.25 pF photodiode capacitance is achieved. The power consumption for a single front-end amplifier circuit is 4.2 mW, and for the second stage TIA is 10.3 mW with a single 1.8 V supply.
Keywords :
CMOS integrated circuits; III-V semiconductors; MIMO communication; broadband networks; current mirrors; diversity reception; flip-chip devices; gallium arsenide; indium compounds; integrated optoelectronics; low-power electronics; metal-semiconductor-metal structures; optical receivers; photodetectors; telecommunication channels; 7-channel diversity receiver front-end; CMOS technology; InGaAs; bit rate 5 Gbit/s; current-mode imaging receiver; equal-gain combining; flip-chip bonding; free-space optical MIMO communication; front-end amplifier circuit; low-input-impedance current mirror; metal-semiconductor-metal photodetector array; photodiode capacitance; power 10.3 mW; power 4.2 mW; second stage transimpedance amplifier; size 180 nm; voltage 1.8 V; Bonding; CMOS technology; Diversity reception; Indium gallium arsenide; MIMO; Mirrors; Optical amplifiers; Optical imaging; Optical receivers; Photodetectors;
Conference_Titel :
Circuits and Systems, 2009. MWSCAS '09. 52nd IEEE International Midwest Symposium on
Conference_Location :
Cancun
Print_ISBN :
978-1-4244-4479-3
Electronic_ISBN :
1548-3746
DOI :
10.1109/MWSCAS.2009.5236130
