Mohamed Atef

1.25 Gbit/s Over 50 m Step-Index Plastic Optical Fiber Using a Fully Integrated Optical Receiver With an Integrated Equalizer

A single-chip optical receiver with an integrated equalizer is used to achieve a high performance gigabit transmission over step-index plastic optical fiber (SI-POF). The integrated equalizer can compensate for different POF lengths up to 50 m. The integrated optical receiver is fabricated in a low-cost silicon 0.6 μ m BiCMOS technology and has a power consumption of 100 mW. Real-time transmission at data rates of 1.8 Gbit/s over 20 m SI-POF and 1.25 Gbit/s over 50 m SI-POF with high sensitivities and BER of 10-9 is achieved. The optical transmitter is based on an edge emitting laser.

Avalanche Double Photodiode in 40-nm Standard CMOS Technology

This paper investigates a silicon (Si) avalanche double photodiode (ADPD) fabricated in 40-nm standard CMOS technology. Two different types of double photodiodes (DPDs) will be introduced. The first one is a P-well/deep-N-well/P-substrate(PW/DNW/P-substrate) DPD, and the second one is a P+/N-well/P-substrate (P+/NW/P-substrate) DPD. The basic structure of the proposed ADPD is formed by P+/NW and NW/P-substrate junctions in which the avalanche effect occurs at the P+/NW junction. The P+/NW/P-substrate ADPD demonstrates responsivity of 0.84 A/W and a 3-dB electrical bandwidth of 0.7 GHz at 850 nm. For 660 nm, the ADPD shows a responsivity of 0.49 A/W with an electrical bandwidth of 1.8 GHz. For 520 nm, a responsivity of 2.04 A/W and an electrical bandwidth of 1.4 GHz are achieved.

Optical Receiver Using Noise Cancelling With an Integrated Photodiode in 40 nm CMOS Technology

A transimpedance amplifier (TIA) based on an inverting voltage amplifier with a shunt feedback resistor using a noise cancelling technique is presented. The TIA is followed by two stages of differential limiting amplifiers and the last stage is a 50 Ω differential output driver to provide an interface to the measurement setup. The TIA shows a measured optical sensitivity of -20.7 dBm for a BER of 10-9 using an external photodiode (PD). Another chip with the same TIA and an integrated N+/Psub PD is also introduced. The optical receiver achieves a measured transimpedance gain of 78 dBΩ, 1.5 GHz bandwidth and a measured input referred noise current density of 7.2 pA/√Hz up to 1.5 GHz. The power consumption of the TIA is only 4.1 mW and the complete chip dissipates 12 mW for a single 1 V supply voltage.

10Gbit/s 2mW inductorless transimpedance amplifier

This work presents the design and performance of a 10Gbit/s transimpedance amplifier (TIA) implemented in a 40nm CMOS technology. The introduced TIA uses an inverter with active common-drain feedback (ICDF-TIA). The TIA is followed by a two-stage differential amplifier and a 50Ω differential output driver to provide an interface to the measurement setup. The optical receiver shows an optical sensitivity of −19dBm for a BER= 10−12. The transimpedance amplifier achieves a transimpedance gain of 47dBΩ, 8GHz bandwidth with 0.45pF total input capacitance for the photodiode, ESD protection and input PAD. The TIA occupies 0.0002mm2 whereas the complete optical receiver occupies a chip area of 0.16mm2. The power consumption of the TIA is only 2mW and the complete chip dissipates 16mW for a 1.1V single supply voltage. The complete optical receiver has a 58dBΩ transimpedance gain and 7GHz bandwidth.

An integrated optical receiver for multilevel data communication over plastic optical fiber

A BiCMOS integrated optical receiver with high sensitivity and linearity is presented. An automatic gain control transimpedance amplifier and linear post amplifiers are used to maintain a high linearity with multilevel modulation. Using multilevel signaling and large-diameter integrated photodiodes make the presented optical receiver suitable for small-bandwidth high-attenuation large-core PMMA step index plastic optical fiber. A measured sensitivity of −31dBm (BER=10−9) at 250Mb/s is presented for a binary signal. A data rate of 500Mb/s and a sensitivity of −25dBm (BER=10−9) are achieved with four-level pulse amplitude modulation (4-PAM). An error-free transmission over 40m PMMA step index plastic optical fiber was achieved at 500Mb/s using 4-PAM signaling with the presented multilevel optical receiver.

2.5Gbit/s transimpedance amplifier using noise cancelling for optical receivers

This work presents the design and performance of a 2.5Gbit/s transimpedance amplifier (TIA) for optical receivers implemented in a 40nm CMOS technology. The TIA is based on an inverting voltage amplifier with a shunt feedback resistor using noise cancelling technique to reduce the input noise. The TIA is followed by two stages of differential limiting amplifiers and the last stage is a 50Ω differential output driver to provide an interface to the measurement setup. The TIA shows a post layout simulated optical sensitivity of −25dBm for a BER= 10−12 and an optical power dynamic range of 25dB. The complete chip achieves a transimpedance gain of 79.5dBΩ, 1.5GHz bandwidth and occupies a chip area of 0.16mm2. The power consumption of the TIA is only 4.5mW and the complete chip dissipates 15mW for a 1.1V single supply voltage.

Gigabit transmission over PMMA step-index plastic optical fiber using an optical receiver for multilevel communication

1Gbit/s transmission with four-level pulse amplitude modulation over low cost 20m PMMA step-index plastic optical fiber at a BER of 10−8 was achieved by using an integrated optical receiver designed for multilevel signalling.

10Gb/s inverter based cascode transimpedance amplifier in 40nm CMOS technology

This work presents the design and performance of a 10Gbit/s transimpedance amplifier (TIA) implemented in a 40nm CMOS technology. The introduced TIA uses an inverter based cascode feedback (Inv-Cascode-TIA) with shunt feedback resistor. The TIA is followed by an one-stage single-ended common-source amplifier (CS), a two-stage differential amplifier and a 50Ω differential output driver to provide an interface to the measurement setup. The optical receiver shows an optical sensitivity of -21.4dBm for a BER= 10-12. The transimpedance amplifier achieves a transimpedance gain of 55.3dBΩ, 8GHz bandwidth with 0.45pF total input capacitance. The power consumption of the TIA is 3.01mW and the complete chip dissipates 19.25mW for a 1.2V single supply voltage. The complete optical receiver has a 69.2dBΩ transimpedance gain and 7GHz bandwidth.

A gigabit fully integrated plastic optical fiber receiver for a RC-LED source

The presented work describes a plastic optical fiber receiver for gigabit transmission using a resonant cavity light emitting diode (RC-LED). The integrated optical receiver is realized in 0.6μm BiCMOS technology. The main novelty of the presented design is the integration of the equalizer with the optical receiver. A large area Si photodiode is integrated with the optical receiver. The design combines a TIA, equalizer and post amplifier stage followed by a 50 Ω output driver. To minimize power supply noise and substrate noise, a fully differential design is used. A dummy TIA provides a symmetrical input signal reference and a control loop is used to compensate the offset levels. The total transimpedance of the complete receiver chain is in the range of 85dBΩ. The value of the DC gain and the corner frequency of the equalizer can be adapted via an external control voltage to adapt the design to different SI-POF lengths and RC-LED limited bandwidths. The optical receiver operates at a 3.3 V single power supply and the total current consumption is 31mA. The presented optical receiver succeeded to equalize the low-bandwidth transmission system (RC-LED and 50m POF). A data rate of 1Gbit/s can be transmitted over 50m SI-POF with a sensitivity of -13dBm at BER of 10-9.

A feature exploration methodology for learning based cuffless blood pressure measurement using photoplethysmography

In this work, we propose a feature exploration method for learning-based cuffless blood pressure measurement. More specifically, to efficiently explore a large feature space from the photoplethysmography signal, we have applied several analytical techniques, including random error elimination, adaptive outlier removal, maximum information coefficient and Pearsons correlation coefficient based feature assessment methods. We evaluate fifty-seven possible feature candidates and propose three separate feature sets with each containing eleven features to predict the systolic blood pressure (SBP), diastolic blood pressure (DBP) and mean blood pressure (MBP), respectively. From our experimental results on a realistic dataset, this work achieves 4.77±7.68, 3.67±5.69 and 3.85±5.87 mmHg prediction accuracy for SBP, DBP and MBP. In summary, using the proposed light-weight features, the proposed predictors can successfully achieve a Grade A in two standards proposed by the American National Standards of the Association for the Advancement of Medical Instrumentation (AAMI) and British Hypertension Society (BHS).