All photonic analogue to digital and digital to analogue conversion techniques for digital radio over fibre system applications

Copyright @ 2011 IEEEWideband electronic analogue to digital conversion (ADC) systems have critical problems encountered in high-frequency broadband communication systems that the recent electronic ADCs (EADC) have experienced those such as uncertainty of sampling time. In this paper, an all photonic sampling and quantization ADC and photonic digital to analogue conversion system with six effective number of bits (ENOB) is designed. By using this photonic ADC (PADC), a novel digital radio over fibre link for wireless radio frequency (RF) signal transportation over 20 Km single mode fibre has been designed whose performance is investigated in this paper. In the digital radio over fibre, the dynamic range is independent of the fibre length

Digital radio over fibre for future broadband wireless access network solution

Copyright @ 2010 IEEEDigital systems are more flexible and environment-process-tolerant than analogue systems. They are more reliable and robust against cross-talk, interference and channel noises, and are capable of covering higher dynamic range than analogue systems. Wideband electronic analogue to digital conversion (ADC) systems have critical problems encountered in high-frequency broadband communication systems that the recent electronic ADCs (EADC) have experienced those such as uncertainty of sampling time. In this paper, an 80Gigasample/s all photonic sampling and quantization ADC and photonic digital to analogue conversion system with six effective number of bits (ENOB) is designed. By using this Photonic ADC (PADC), a digital radio over fibre link for wireless radio frequency (RF) signal transportation over 50 km single mode fibre has been designed whose performance is investigated in this paper

Highly-sensitive superconducting quantum interference proximity transistor

We report the design and implementation of a high-performance superconducting quantum interference proximity transistor (SQUIPT) based on aluminum-copper (Al-Cu) technology. With the adoption of a thin and short copper nanowire we demostrate full phase-driven modulation of the proximity-induced minigap in the normal metal density of states. Under optimal bias we record unprecedently high flux-to-voltage (up to 3 mV/$\Phi_0$) and flux-to-current (exceeding 100 nA/$\Phi_0$) transfer function values at sub-Kelvin temperatures, where $\Phi_0$ is the flux quantum. The best magnetic flux resolution (as low as 500 n$\Phi_0/\sqrt{Hz}$ at 240 mK, being limited by the room temperature pre-amplification stage) is reached under fixed current bias. These figures of merit combined with ultra-low power dissipation and micrometer-size dimensions make this mesoscopic interferometer attractive for low-temperature applications such as the investigation of the magnetization of small spin populations.Comment: 7 pages, 5 color figure