In theoty, engineered anomalous transmission in passive materials and waveguide devices can be used to compensate for wavetorm distortions. However, they suffer from inherent dissipation. Recently, active non-Foster e...In theoty, engineered anomalous transmission in passive materials and waveguide devices can be used to compensate for wavetorm distortions. However, they suffer from inherent dissipation. Recently, active non-Foster elements with imaginary immittance monotonically decreasing with frequency have shown important potentials in broadening bandwidths of electromagnetic devices. So far, they are implemented besed on negative impedance convertors （NICs） loaded with Foster devices. This makes them intrinsically one-port elements and thus cannot be used to compensate for distortions of signals. We construct a two-port network with a non-Foster transmission coefticient based on an unconventional use of NICs. Simulation and experiments show that it can compensate for extremely distorted signals. The proposed method can be used to broaden existing applications in different areas such as antennas, circuits and systems, and physical-layer signal processing.展开更多
Photonic generation of radio-frequency（RF） arbitrary microwave waveform with ultra-wide frequency tunable range based on a dispersion compensated optoelectronic oscillator（OEO） is proposed and experimentally demon...Photonic generation of radio-frequency（RF） arbitrary microwave waveform with ultra-wide frequency tunable range based on a dispersion compensated optoelectronic oscillator（OEO） is proposed and experimentally demonstrated. Dispersion compensation scheme and specially designed fiber Bragg grating（FBG）-based Fabry-Perot（F-P） filters are employed in the OEO loop to realize a frequency tunable range of 3.5-45.4 GHz. An optimization process provided by the combination of an erbium-doped fiber amplifier（EDFA）and FBG is employed to improve the signal-to-noise ratio（SNR） of final RF signals. The generation of linearfrequency and phase-coded microwave waveforms, with a tunable carrier frequency ranging from 4 to 45 GHz and tuned chirping bandwidths or code rates, is experimentally demonstrated.展开更多
基金Supported by the National Natural Science Foundation of China under Grant Nos 61771421,61771422,61528014 and 6140139the Zhejiang Provincial Natural Science Foundation under Grant No LY16F010009
文摘In theoty, engineered anomalous transmission in passive materials and waveguide devices can be used to compensate for wavetorm distortions. However, they suffer from inherent dissipation. Recently, active non-Foster elements with imaginary immittance monotonically decreasing with frequency have shown important potentials in broadening bandwidths of electromagnetic devices. So far, they are implemented besed on negative impedance convertors （NICs） loaded with Foster devices. This makes them intrinsically one-port elements and thus cannot be used to compensate for distortions of signals. We construct a two-port network with a non-Foster transmission coefticient based on an unconventional use of NICs. Simulation and experiments show that it can compensate for extremely distorted signals. The proposed method can be used to broaden existing applications in different areas such as antennas, circuits and systems, and physical-layer signal processing.
文摘Photonic generation of radio-frequency（RF） arbitrary microwave waveform with ultra-wide frequency tunable range based on a dispersion compensated optoelectronic oscillator（OEO） is proposed and experimentally demonstrated. Dispersion compensation scheme and specially designed fiber Bragg grating（FBG）-based Fabry-Perot（F-P） filters are employed in the OEO loop to realize a frequency tunable range of 3.5-45.4 GHz. An optimization process provided by the combination of an erbium-doped fiber amplifier（EDFA）and FBG is employed to improve the signal-to-noise ratio（SNR） of final RF signals. The generation of linearfrequency and phase-coded microwave waveforms, with a tunable carrier frequency ranging from 4 to 45 GHz and tuned chirping bandwidths or code rates, is experimentally demonstrated.
