A full-band direct-conversion receiver using a microwave photonic in-phase and quadrature （I/Q） mixer is proposed and experimentally evaluated in terms of radio frequency （RF） range, port isolation, phase imbalanc...A full-band direct-conversion receiver using a microwave photonic in-phase and quadrature （I/Q） mixer is proposed and experimentally evaluated in terms of radio frequency （RF） range, port isolation, phase imbalance, conversion gain, noise figure, spurious-free dynamic range, and error vector magnitude. The proposed microwave photonic I/Q mixer shows significant advantages in locM oscillator leakage and I/Q phase imbalance over entire RF bands, which are recognized as major drawbacks of conventional direct-conversion receivers.展开更多
To solve the satellite repeater＇s flexible and wideband frequency conversion problem, we propose a novel microwave photonic repeater system, which can convert the upload signal＇s carrier to six different frequencies...To solve the satellite repeater＇s flexible and wideband frequency conversion problem, we propose a novel microwave photonic repeater system, which can convert the upload signal＇s carrier to six different frequencies. The scheme employs one 20 GHz bandwidth dual-drive Mach-Zehnder modulator （MZM） and two 10 GHz bandwidth MZMs. The basic principle of this scheme is filtering out two optical sidebands after the optical carrier suppression （OCS） modulation and combining two sidebands modulated by the input radio frequency （RF） signal. This structure can realize simultaneous multi-band frequency conversion with only one frequency-fixed microwave source and prevent generating harmful interference sidebands by using two corresponding optical filters after optical modulation. In the simulation, one C-band signal of 6 GHz carrier can be successfully converted to 12 GHz （Ku-band）, 28 GHz, 34 GHz, 40 GHz, 46 GHz （Ka-band） and 52 GHz （V-band）, which can be an attractive method to realize multi-band microwave photonic satellite repeater. Alternatively, the scheme can be configured to generate multi-band local oscillators （LOs） for widely satellite onboard clock distribution when the input RF signal is replaced by the internal clock source.展开更多
We theoretically design a power-efficient ultra-wideband pulse generator by combining three monocycle pulses with different weights. We also experimentally demonstrate a feasible scheme to generate such power-efficien...We theoretically design a power-efficient ultra-wideband pulse generator by combining three monocycle pulses with different weights. We also experimentally demonstrate a feasible scheme to generate such power-efficient ultra-wideband waveforms using cross-phase modulation in a single semiconductor optical amplifier. The designed ultra-wideband pulse fully satisfies the requirements for the spectral mask specified by the Federal Communications Commission with high power efficiency. In the experiment, a power-efficient ultra-wideband waveform with a pulse duration of 310 ps is achieved, and the power efficiency is greatly improved compared with that of a single nlonocycle pulse or a mixture of two monoeycles.展开更多
We propose and demonstrate a scheme to implement photonic multi-shape ultra-wideband（UWB） signal generation using a semiconductor optical amplifier（SOA） based nonlinear optical loop mirror（NOLM）.By employing the...We propose and demonstrate a scheme to implement photonic multi-shape ultra-wideband（UWB） signal generation using a semiconductor optical amplifier（SOA） based nonlinear optical loop mirror（NOLM）.By employing the cross phase modulation（XPM） effect,cross gain modulation（XGM）,or both,multi-shape UWB waveforms are generated including monocycle,doublet,triplet,and quadruplet pulses.Both the shapes and polarities of the generated pulses are flexible to adjust,which may be very useful in UWB pulse shape modulation and pulse polarity modulation.展开更多
We provide an overview of our recent work on developing subwavelength grating （SWG） waveguide devices as an enabling technology for integrated microwave photonics. First, we describe wavelength-selective SWG wavegui...We provide an overview of our recent work on developing subwavelength grating （SWG） waveguide devices as an enabling technology for integrated microwave photonics. First, we describe wavelength-selective SWG waveguide filters, including ring resonators, Bragg gratings, and contradirectional couplers. Second, we discuss the development of an index variable optical true time delay line that exploits spatial diversity in an equal-length waveguide array. These SWG waveguide components are fundamental building blocks for realizing more complex structures for advanced microwave photonic signal processing.展开更多
Compressive sampling （CS） has attracted considerable attention in microwave and radio frequency （RF） fields in recent years. It enables the acquisition of high-frequency signals at a rate much smaller than their N...Compressive sampling （CS） has attracted considerable attention in microwave and radio frequency （RF） fields in recent years. It enables the acquisition of high-frequency signals at a rate much smaller than their Nyquist rates. Combined with photonics technology, traditional CS systems can significantly enlarge their operating bandwidth, which offers great potential for spectrum sensing in cognitive radios. In this Letter, we review our recent work on photonic CS systems for wideband spectrum sensing. First, a proof-of-concept photonics-assisted CS system is demonstrated; it is capable of acquiring numerous radar pulses in an instantaneous bandwidth spanning from 500 MHz to 5 GHz with a 500-MHz analog-to-digital converter （ADC）. To further reduce the acquisition bandwidth, multi-channel photonics-assisted CS systems are proposed for the first time, enabling the acquisition of multi-tone signals with frequencies up to 5 GHz by using 120-MHz ADCs. In addition, the system bandwidth is increased from 5 to 20 GHz by employing time-interleaved optical sampling.展开更多
In this paper, a novel method of in-line chromatic dispersion (CD) measurement is proposed, we theoretically and experimentally demonstrated the CD measurement of 10-Gbit/s NRZ and RZ signals by a novel RF spectrum ph...In this paper, a novel method of in-line chromatic dispersion (CD) measurement is proposed, we theoretically and experimentally demonstrated the CD measurement of 10-Gbit/s NRZ and RZ signals by a novel RF spectrum phase detection technique, this is performed using in-band tone monitoring RF, electrically down-converted to direct current (DC) or a low intermediate-frequency (IF) of less than 1MHz through electronic mixing with local oscillator (LO) of 2.4 GHz. The measurement provides a large CD measuring range with good accuracies (±2000 ± 35 ps/nm), and independent of the bit-rate and data format. In addition, the use of electronic mixer and low-speed detectors makes it cost effective for in-line CD measurement.展开更多
A 4× 4 multiple-input multiple-output coherent microwave photonic （MWP） link to transmit four wireless signals with an identical microwave center frequency over a single optical wavelength based on optical inde...A 4× 4 multiple-input multiple-output coherent microwave photonic （MWP） link to transmit four wireless signals with an identical microwave center frequency over a single optical wavelength based on optical independent sideband （OISB） modulation and optical orthogonal modulation with an improved spectral efficiency is proposed and experimentally demonstrated. At the transmitter, the OISB modulation and optical orthogonal modulation are implemented to generate an OISB signal using a dual-parallel Mach-Zehnder modulator （DP- MZM） driven by four microwave orthogonal frequency-division multiplexing （OFDM） signals with an identical microwave center frequency. At the receiver, the OISB signal is coherently detected at a coherent receiver where a free-running local oscillator （LO） laser source is employed. Digital signal processing is then used to recover the four OFDM signals, to eliminate the phase noise from the transmitter laser source and the LO laser source, and to cancel the unstable wavelength difference between the wavelengths of the transmitter laser source and the LO laser source. Error-free transmission of three 16 quadrature amplitude modulation （16-QAM） 1 Gbps OFDM signals and one 16-QAM 1.5 Gbps OFDM signal at a microwave center frequency of 2.91 GHz over a 10 km single-mode fiber is experimentally demonstrated.展开更多
Ultra-low phase noise performance is required for frequency agile local oscillators, which are the core for high resolution imagers, spectrum analyzers, and high speed data communications. A forced opto-electronic osc...Ultra-low phase noise performance is required for frequency agile local oscillators, which are the core for high resolution imagers, spectrum analyzers, and high speed data communications. A forced opto-electronic oscillator （OEO） benefits from frequency stabilization techniques for realizing a clean and low phase noise source at micro- wave and millimeter wave frequencies. Forced oscillation techniques of self-injection locking and self-phase lock loop are combined to provide an ultra-low oscillator phase noise both close-in and far-away from the carrier frequency, while a tunable yttrium iron garnet microwave filter combined with a wavelength tuned transversal filter are employed to implement both coarse and fine frequency tuning for a tunable X-band OEO. A phase noise of -137 dBc/Hz at an offset frequency of 10 kHz is achieved covering the frequencies of 9 to 11 GHz with a fine frequency tuning resolution of 44 Hz/pm and coarse tuning of 25 MHz/mA. Moreover, the long term stability of the output signal is tested, and a maximum frequency drift of 2 kHz is measured within 60 min for the X-band synthesizer.展开更多
A wideband-generalized pattern multiplication approach to evaluate the performance of an optical beamform- ing-based wideband antenna array is proposed and experimentally demonstrated, which enables the far-field meas...A wideband-generalized pattern multiplication approach to evaluate the performance of an optical beamform- ing-based wideband antenna array is proposed and experimentally demonstrated, which enables the far-field measurement of a large wideband array with a small anechoic chamber. Because the optimum reception of a wideband microwave signal is highly related to the time-domain distortions of the beamforming system, a correlation-receiver-based radiation pattern is applied to take the fidelity of the wideband signals into account. A four-element optical beamforming system is built to verify the feasibility of the proposed method. The results achieved by the DrODosed method agree well with the conventional direct measurements.展开更多
基金supported in part by the National 863Program of China(No.2015AA016903)the National Natural Science Foundation of China(No.61431003,61601049,and 61401411)+1 种基金the Innovation Foundation of China Electronics Technology Group Corporation(CETC)the Innovation Foundation of Key Laboratory of Aerospace Information Applications at CETC
文摘A full-band direct-conversion receiver using a microwave photonic in-phase and quadrature （I/Q） mixer is proposed and experimentally evaluated in terms of radio frequency （RF） range, port isolation, phase imbalance, conversion gain, noise figure, spurious-free dynamic range, and error vector magnitude. The proposed microwave photonic I/Q mixer shows significant advantages in locM oscillator leakage and I/Q phase imbalance over entire RF bands, which are recognized as major drawbacks of conventional direct-conversion receivers.
基金supported by the National Natural Science Foundation of China (61302060,91438117,91538202)the CAST Fund for Distinguished Young TalentsCASC Scientific and Technological Innovative Research and Design Projects
文摘To solve the satellite repeater＇s flexible and wideband frequency conversion problem, we propose a novel microwave photonic repeater system, which can convert the upload signal＇s carrier to six different frequencies. The scheme employs one 20 GHz bandwidth dual-drive Mach-Zehnder modulator （MZM） and two 10 GHz bandwidth MZMs. The basic principle of this scheme is filtering out two optical sidebands after the optical carrier suppression （OCS） modulation and combining two sidebands modulated by the input radio frequency （RF） signal. This structure can realize simultaneous multi-band frequency conversion with only one frequency-fixed microwave source and prevent generating harmful interference sidebands by using two corresponding optical filters after optical modulation. In the simulation, one C-band signal of 6 GHz carrier can be successfully converted to 12 GHz （Ku-band）, 28 GHz, 34 GHz, 40 GHz, 46 GHz （Ka-band） and 52 GHz （V-band）, which can be an attractive method to realize multi-band microwave photonic satellite repeater. Alternatively, the scheme can be configured to generate multi-band local oscillators （LOs） for widely satellite onboard clock distribution when the input RF signal is replaced by the internal clock source.
基金supported by the National Basic Research Program of China (Grant No. 2011CB301704)the National Natural Science Foundation of China (Grant No. 60901006)the Fundamental Research Funds for the Central Universities of China (Grant No. 2010QN033)
文摘We theoretically design a power-efficient ultra-wideband pulse generator by combining three monocycle pulses with different weights. We also experimentally demonstrate a feasible scheme to generate such power-efficient ultra-wideband waveforms using cross-phase modulation in a single semiconductor optical amplifier. The designed ultra-wideband pulse fully satisfies the requirements for the spectral mask specified by the Federal Communications Commission with high power efficiency. In the experiment, a power-efficient ultra-wideband waveform with a pulse duration of 310 ps is achieved, and the power efficiency is greatly improved compared with that of a single nlonocycle pulse or a mixture of two monoeycles.
基金Project supported by the National Basic Research Program of China (Grant No. 2011CB301704)the National Natural Science Foundation for Distinguished Young Scholars (Grant No. 61125501)the National Natural Science Foundation of China (Grant Nos. 60901006 and 11174096)
文摘We propose and demonstrate a scheme to implement photonic multi-shape ultra-wideband（UWB） signal generation using a semiconductor optical amplifier（SOA） based nonlinear optical loop mirror（NOLM）.By employing the cross phase modulation（XPM） effect,cross gain modulation（XGM）,or both,multi-shape UWB waveforms are generated including monocycle,doublet,triplet,and quadruplet pulses.Both the shapes and polarities of the generated pulses are flexible to adjust,which may be very useful in UWB pulse shape modulation and pulse polarity modulation.
基金supported in part by the Natural Sciences and Engineering Research Council of Canadathe Fonds de Recherche du Québec-Nature et Technologies,and the Royal Society
文摘We provide an overview of our recent work on developing subwavelength grating （SWG） waveguide devices as an enabling technology for integrated microwave photonics. First, we describe wavelength-selective SWG waveguide filters, including ring resonators, Bragg gratings, and contradirectional couplers. Second, we discuss the development of an index variable optical true time delay line that exploits spatial diversity in an equal-length waveguide array. These SWG waveguide components are fundamental building blocks for realizing more complex structures for advanced microwave photonic signal processing.
基金supported by the National Basic Research Program of China(No.2012CB315703)the National Natural Science Foundation of China(Nos.61271134 and 61120106001)
文摘Compressive sampling （CS） has attracted considerable attention in microwave and radio frequency （RF） fields in recent years. It enables the acquisition of high-frequency signals at a rate much smaller than their Nyquist rates. Combined with photonics technology, traditional CS systems can significantly enlarge their operating bandwidth, which offers great potential for spectrum sensing in cognitive radios. In this Letter, we review our recent work on photonic CS systems for wideband spectrum sensing. First, a proof-of-concept photonics-assisted CS system is demonstrated; it is capable of acquiring numerous radar pulses in an instantaneous bandwidth spanning from 500 MHz to 5 GHz with a 500-MHz analog-to-digital converter （ADC）. To further reduce the acquisition bandwidth, multi-channel photonics-assisted CS systems are proposed for the first time, enabling the acquisition of multi-tone signals with frequencies up to 5 GHz by using 120-MHz ADCs. In addition, the system bandwidth is increased from 5 to 20 GHz by employing time-interleaved optical sampling.
文摘In this paper, a novel method of in-line chromatic dispersion (CD) measurement is proposed, we theoretically and experimentally demonstrated the CD measurement of 10-Gbit/s NRZ and RZ signals by a novel RF spectrum phase detection technique, this is performed using in-band tone monitoring RF, electrically down-converted to direct current (DC) or a low intermediate-frequency (IF) of less than 1MHz through electronic mixing with local oscillator (LO) of 2.4 GHz. The measurement provides a large CD measuring range with good accuracies (±2000 ± 35 ps/nm), and independent of the bit-rate and data format. In addition, the use of electronic mixer and low-speed detectors makes it cost effective for in-line CD measurement.
基金supported by the Natural Sciences and Engineering Research Council of Canada(NSERC)
文摘A 4× 4 multiple-input multiple-output coherent microwave photonic （MWP） link to transmit four wireless signals with an identical microwave center frequency over a single optical wavelength based on optical independent sideband （OISB） modulation and optical orthogonal modulation with an improved spectral efficiency is proposed and experimentally demonstrated. At the transmitter, the OISB modulation and optical orthogonal modulation are implemented to generate an OISB signal using a dual-parallel Mach-Zehnder modulator （DP- MZM） driven by four microwave orthogonal frequency-division multiplexing （OFDM） signals with an identical microwave center frequency. At the receiver, the OISB signal is coherently detected at a coherent receiver where a free-running local oscillator （LO） laser source is employed. Digital signal processing is then used to recover the four OFDM signals, to eliminate the phase noise from the transmitter laser source and the LO laser source, and to cancel the unstable wavelength difference between the wavelengths of the transmitter laser source and the LO laser source. Error-free transmission of three 16 quadrature amplitude modulation （16-QAM） 1 Gbps OFDM signals and one 16-QAM 1.5 Gbps OFDM signal at a microwave center frequency of 2.91 GHz over a 10 km single-mode fiber is experimentally demonstrated.
文摘Ultra-low phase noise performance is required for frequency agile local oscillators, which are the core for high resolution imagers, spectrum analyzers, and high speed data communications. A forced opto-electronic oscillator （OEO） benefits from frequency stabilization techniques for realizing a clean and low phase noise source at micro- wave and millimeter wave frequencies. Forced oscillation techniques of self-injection locking and self-phase lock loop are combined to provide an ultra-low oscillator phase noise both close-in and far-away from the carrier frequency, while a tunable yttrium iron garnet microwave filter combined with a wavelength tuned transversal filter are employed to implement both coarse and fine frequency tuning for a tunable X-band OEO. A phase noise of -137 dBc/Hz at an offset frequency of 10 kHz is achieved covering the frequencies of 9 to 11 GHz with a fine frequency tuning resolution of 44 Hz/pm and coarse tuning of 25 MHz/mA. Moreover, the long term stability of the output signal is tested, and a maximum frequency drift of 2 kHz is measured within 60 min for the X-band synthesizer.
基金supported in part by the NSFC Program(Nos.61422108 and 61527820)the Jiangsu Provincial Program for High-level Talents in Six Areas(No.DZXX-034)+1 种基金the“333 Project”of Jiangsu Province(BRA2015343)the Fundamental Research Funds for the Central Universities
文摘A wideband-generalized pattern multiplication approach to evaluate the performance of an optical beamform- ing-based wideband antenna array is proposed and experimentally demonstrated, which enables the far-field measurement of a large wideband array with a small anechoic chamber. Because the optimum reception of a wideband microwave signal is highly related to the time-domain distortions of the beamforming system, a correlation-receiver-based radiation pattern is applied to take the fidelity of the wideband signals into account. A four-element optical beamforming system is built to verify the feasibility of the proposed method. The results achieved by the DrODosed method agree well with the conventional direct measurements.
