state of the art FEC [13]. DP-QPSK format is the ever succeed modulation at the highest possible baud rate of 56 GBd with measured BER and EVM of 9 3 10 24 and 27%rms, respectively. In Figures 3(a)-(d), we show the received constellation formats and their respectively achieved data rates in back-to-back setting. This measurement is particularly interesting because it highlights a design tradeoff between the resolution of the DAC, its 3-dB bandwidth, and its sampling rate. This shows that our optical transmission setup can be exploited for particular needs of extremely high baud rates at the expense of modulation order. This feature is very attractive in next generation flex-grid networks and the building of super channels based networks [14].
CONCLUSIONWe experimentally demonstrated the effect of state-of-the-art CMOS based DAC on next generation high speed optical transceivers. The two-fold oversampling allows the transmission of DP-128QAM over 32 GBd (i.e., 448 bps) over single carrier. Sampling factor less than two-fold criterion allows the transmission of maximum DP-56 GBd optical signal for DAC sampling rate of 64 GSa/s on the expense of high signal bandwidth, which reduces the DAC ENOB. 3. A. Ragheb, et al. Up to 64 QAM/32 Gbaud flexible dual polarization transmitter for future elastic optical networks, Opt Eng 52 (2013), 115102. 4. S. Randel, et al., Generation of 224-Gb/s multicarrier offset-QAM using a real-time transmitter, Optical Fiber Communication Conference and Exposition (OFC/
A simple design of compact ultra-wideband, ultra-thin metamaterial microwave absorber has been presented. The unit cell of the proposed design is composed of diagonally placed 'microstrip bend' like patches printed on grounded dielectric substrate. The simulation results demonstrate the 10-dB absorption bandwidth of 7.19 GHz from 10.45 GHz to 17.64 GHz and FWHM (full width at half maximum) bandwidth of 11.43 GHz from 9.61 GHz to 21.04 GHz. The proposed design presents more than 90% absorption for a bandwidth of 1.02 GHz at wide angle of incidence up to 60 0. The absorption mechanism has been analyzed through surface current and electromagnetic field distributions. The proposed design has been fabricated and experimentally tested for its 10-dB absorption bandwidth under different polarization and oblique angles of incidence of electromagnetic wave. The designed absorber is low profile (unit cell size is ~0.257 λ 0 at the center frequency corresponding to 10-dB absorption bandwidth), ultrathin (~λ 0 /14 thick at the center frequency) and provides a novel design of wideband absorber for many useful applications.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.