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.

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.

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

Simplification is an important design step of water supply and irrigation pipes networks. It is recognized by making the original network easier to be understood and analyzed. Water hammer in water-supply networks may give rise to high and low pressures, due to the superposition of reflected pressure waves. The effect of pipes networks’ simplification on water hammer phenomenon is investigated. This study uses a simple two loops pipes network composed of 12 high density polyethylenes (HDPE) pipes with different diameters, thicknesses, and roughness coefficients representing of a general parallel/series system. The network is fed from a boundary head reservoir and loaded by either distributed or concentrated boundary water demands. According to both hydraulic and hydraulic plus water quality equivalence, three levels of simplifications on the original network are performed. Also, the effect of water demands’ concentration on the transient flow is checked. The transient flow in the network is initialized by either concentrated or distributed boundary water demands which are suddenly shut-off or released. Water hammer and mass oscillation (WHAMO) software which uses the implicit finite difference scheme for solving the momentum and continuity equations at unsteady-state case is used in the simulation. All scenarios produced results showed that both hydraulic equivalence and demands’ concentration simplifications increase the transient pressure and flow rate in the simplified network compared with the original one. However, hydraulic plus water quality equivalence simplification results in an adverse effect. It was found that, as the degree of simplification increases the transient pressure head and flow rate of the simplified network deviate more from those of the original network. Therefore, simplifications of the distribution networks should be done with very careful caution.

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