Article
Chemistry, Multidisciplinary
Xinxin Gao, Ze Gu, Qian Ma, Wen Yi Cui, Tie Jun Cui, Chi Hou Chan
Summary: Driven by the demands for compact interconnects and fast information transfer, research on spoof plasmonic metamaterials has been focused on achieving individual modulation of amplitude or phase at single frequencies due to structural limitations. This study proposes and experimentally demonstrates an ultra-thin reprogrammable modulator consisting of a spoof surface plasmonic polariton (SSPP) waveguide and spoof localized surface plasmon (SLSP) resonators, allowing independent control of amplitude and phase of surface waves. By manipulating the SSPP waveguide and SLSP resonators in real-time, various programmable modulations such as amplitude-shift keying, phase-shift keying, quadrature amplitude modulation, and frequency-shift keying can be achieved. Measurement results confirm the potential applications of the reprogrammable plasmonic metamaterial in integrated circuits and communication systems.
ADVANCED FUNCTIONAL MATERIALS
(2023)
Article
Optics
Hassan Termos, Ali Nansour
Summary: This study focuses on a novel concept of transmitting QPSK modulation through electro-optical frequency up-conversion using cascaded MZMs. The design and operating regime peculiarities of the MZMs used as a sampling up-converter mixer in a RoF system are analyzed. Simulation and experimental results show similar behavior, and the conversion gain of the cascaded MZMs link decreases with increasing mixing frequency.
Article
Engineering, Electrical & Electronic
Qiankun Li, Xiongwei Yang, Qi Xu, Jiali Yang, Yameng Li, Huajun Yang
Summary: An all-optical aggregation and de-aggregation scheme is proposed and simulated based on nonlinear effects in high nonlinear fiber, allowing conversion between OOK, QPSK, and 8QAM signals. In the de-aggregation process, the 30 Gbit/s 8QAM signal is converted into a 20 Gbit/s QPSK signal and a 10 Gbit/s BPSK signal using SPM, XPM, FWM, and PA effects. The converted OOK signal is obtained through vector superposition, while in the aggregation process, the QPSK and OOK signals are aggregated into a 30 Gbit/s 8QAM signal again using XPM and PA effects. The proposed scheme is important for network traffic aggregation and de-aggregation with different modulation formats.
OPTICAL FIBER TECHNOLOGY
(2023)
Article
Multidisciplinary Sciences
Changchen Chen, Jane E. Heyes, Jeffrey H. Shapiro, Franco N. C. Wong
Summary: The research team successfully demonstrated a 15.65 GHz frequency shift for classical and nonclassical light using a commercially available quadrature phase-shift keying modulator, with a high carrier-to-sideband ratio of 30 dB. Utilizing the frequency shifter, they showed the improvement of visibility from 62.7% to 89.1% in Hong-Ou-Mandel quantum interference between two photons whose initial frequency spectra overlap only partially.
SCIENTIFIC REPORTS
(2021)
Article
Optics
Yan LI, Muguang Wang, Qi LI, Yuxiao Guo, Beilei Wu, Yan Liu, Desheng Chen
Summary: This paper proposes and demonstrates a novel filter-free photonics-assisted microwave frequency translator with a tunable phase shift and amplitude. The proposed scheme utilizes an integrated dual-polarization quadrature phase shift keying modulator to generate the desired microwave signal through optical conversion. The feasibility of the scheme is verified through theoretical analysis and simulation experiments.
Article
Computer Science, Information Systems
Binyu Li, Haifeng Yao, Lei Zhang, Shoufeng Tong
Summary: A cascaded LMS-LMS adaptive equalization scheme is proposed to improve the transmission performance of QPSK modulated optical signals in medium and weak turbulence channels. The scheme is shown to effectively increase transmission rate and reduce bit-error ratio under different turbulence conditions through simulations and experiments.
Article
Engineering, Multidisciplinary
Bochao Kang, Xu Li, Yangyu Fan, Jian Zhang, Dong Liang, Yongsheng Gao
Summary: This paper proposes a novel optical method for implementing broadband microwave DFS measurement, achieving simultaneous estimation of DFS signals and direction to avoid low-frequency interference. The experiment demonstrates the advantages of the method in system stability and frequency range.
Article
Engineering, Electrical & Electronic
Kyo Inoue
Summary: This paper analyzes the impact of inter-channel crosstalk on QPSK and QAM signals in multichannel optical systems, finding that as the number of channels increases, the BER degradation caused by crosstalk light approaches that caused by Gaussian noise light, and the degradations caused by crosstalk light and Gaussian light are similar for high-level modulation QAM signals.
IEICE TRANSACTIONS ON COMMUNICATIONS
(2021)
Article
Chemistry, Analytical
Yanxia Sun, Chikomborero Shambare, OdunAyo Imoru
Summary: QPSK is a digital modulation technique used in OFDM systems. This paper proposes a hybrid algorithm combining wind-driven optimization and genetic algorithm to address the phase ambiguity and bit error problems in transmission.
Article
Engineering, Electrical & Electronic
Guo-Wei Lu, Hong-Bo Zhang, Zhe Li
Summary: This study presents a scheme for synthesizing single-sideband (SSB) Nyquist high-order QAM using optical subcarrier processing (OSP), which is experimentally validated to be effective. The scheme reduces the requirement for DAC resolution, hence decreasing power consumption and cost, by coherently merging sidebands in the twin-SSB through data aggregation. Additionally, the use of a low-cost laser as the pump source in data aggregation avoids phase noise introduction, contributing to further cost reduction and improved performance.
IEEE JOURNAL OF SELECTED TOPICS IN QUANTUM ELECTRONICS
(2021)
Article
Optics
Hassan Termos, Ali Mansour, Abbass Nasser
Summary: This study investigates the performance of simultaneous up-converted signals using a semiconductor optical amplifier Mach-Zehnder interferometer (SOA-MZI) sampling mixer. Both simulation and experimental analyses were conducted to compare standard and differential modulation modes, revealing that the differential modulation mode exhibits improved performance.
Article
Chemistry, Multidisciplinary
Abdelrahman El Gebali, Rene Landry
Summary: This paper proposes a cascade second-order adaptive direct IIR Notch Filter with a gradient-based algorithm to suppress Continuous-Wave interference, aiming to maximize the receiver's SNR and improve system performance.
APPLIED SCIENCES-BASEL
(2022)
Article
Telecommunications
Soumya P. Dash
Summary: This paper considers an N-branch receive diversity powerline communication system with two users, employing power-domain non-orthogonal multiple access and rotated quadrature phase-shift keying modulation scheme known as semi-orthogonal multiple access for data transmission. The usage of successive-interference cancellation hardware is eliminated by introducing rotation of the data constellation and proposed pre-processing at the receiver end. The paper proposes optimal receiver structures and derives closed-form expressions for the symbol error probability using a characteristic function approach. It also determines the optimal rotation of the QPSK constellation that minimizes the symbol error probability. The results show that the diversity order and optimal rotation angle at high signal-to-noise ratio values depend only on the number of diversity branches. The numerical results confirm the general dependence of the optimal rotation angle on various system parameters, providing insights for the design of a reliable and energy-efficient system without successive-interference cancellation hardware. The optimal rotation angle of the QPSK constellation also leads to novel constellations for the users compared to conventional ones used in digital communication systems.
IEEE TRANSACTIONS ON GREEN COMMUNICATIONS AND NETWORKING
(2022)
Article
Engineering, Electrical & Electronic
Chang Liu, Norman C. Beaulieu
Summary: The paper investigates the jointly optimal maximum likelihood detection of two QPSK signals with an arbitrary relative phase offset, deriving exact symbol error rate and bit error rate formulas. Closed-form union bounds are provided for asymptotic error rate performance, and comparisons with the successive interference cancellation receiver reveal insights on the error rate behaviors of the JO ML detector for each user. The accuracy of the obtained formulas is demonstrated through simulation, showing that error rates in the two-user QPSK case no longer follow classic knowledge on error rate behaviors in single signal detection. Additionally, performance and dB penalty using different modulation types are compared and discussed.
IEEE TRANSACTIONS ON VEHICULAR TECHNOLOGY
(2021)
Article
Engineering, Electrical & Electronic
Ching-Wei Peng, Chi-Wai Chow, Pin-Cheng Kuo, Guan-Hong Chen, Chien-Hung Yeh, Jyehong Chen, Yinchieh Lai
Summary: The 100 Gbit/s silicon photonic coherent receiver utilizes advanced digital signal processing and features integrated 2D polarization-splitting grating couplers, modified mixers, and high speed silicon-germanium photodiodes for DP-QPSK transmission. It eliminates the need for polarization beam splitters and rotators in traditional coherent receivers, with the SiGe PD boasting a bandwidth exceeding 50 GHz.
IEEE PHOTONICS JOURNAL
(2021)
Article
Engineering, Electrical & Electronic
Youngno Youn, Sungmin Cho, Ho-Jin Song, Wonbin Hong
IEEE TRANSACTIONS ON VEHICULAR TECHNOLOGY
(2020)
Article
Engineering, Electrical & Electronic
Hiroshi Hamada, Takuya Tsutsumi, Hideaki Matsuzaki, Takuya Fujimura, Ibrahim Abdo, Atsushi Shirane, Kenichi Okada, Go Itami, Ho-Jin Song, Hiroki Sugiyama, Hideyuki Nosaka
IEEE JOURNAL OF SOLID-STATE CIRCUITS
(2020)
Article
Engineering, Electrical & Electronic
Ho-Jin Song
IEEE MICROWAVE MAGAZINE
(2021)
Article
Computer Science, Information Systems
Gibeom Shin, Kyunghwan Kim, Kangseop Lee, Hyun-Hak Jeong, Ho-Jin Song
Summary: This paper presents a variable-gain amplifier in the 68-78 GHz range, with competitive performance in gain and noise figure achieved by reducing DC power consumption through setting the drain voltage. High-quality shunt capacitors were employed for easy matching with a compact transformer.
Article
Engineering, Electrical & Electronic
Kangseop Lee, Kyunghwan Kim, Gibeom Shin, Ho-Jin Song
Summary: A 40-nm CMOS 70-GHz frequency quadrupler based on a phase-controlled push-push (PCPP) topology was developed, providing high efficiency and harmonic suppression. The use of a transformer-based output amplifier helped mitigate even-order harmonic suppression issues without degrading energy efficiency.
IEEE MICROWAVE AND WIRELESS COMPONENTS LETTERS
(2021)
Article
Engineering, Electrical & Electronic
Seunghoon Lee, Ho-Jin Song
Summary: Analog beamforming technology is used to address technical challenges in mm-wave wireless communications systems, but errors from quantized control and mutual coupling can lead to distortion in radiation patterns. Through statistical analysis, it was found that Beckmann distribution provides an accurate solution for sidelobe level distribution, while Rician distribution reflects errors but may deviate at certain steering angles. Consideration of variance and correlation is important for defining maximum SLL probability.
IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION
(2021)
Article
Multidisciplinary Sciences
Hyejin Hwang, Minsik Kong, Kyunghwan Kim, Doowon Park, Sangyeop Lee, Soojin Park, Ho-Jin Song, Unyong Jeong
Summary: This study introduces a stretchable anisotropic conductive film (S-ACF) that allows high-resolution but low-contact resistance interfacing, and demonstrates stable light operation under large biaxial areal stretching.
Article
Engineering, Electrical & Electronic
Sungmin Cho, Youngno Youn, Wonbin Hong, Ho-Jin Song
Summary: This article introduces a reconfigurable Fresnel zone plate operating at 30 GHz with a low-cost printed circuit board process, achieving beamforming on both the E and H planes. Experimental results demonstrate low power consumption at 30 GHz and successful beamforming of various 5G signals without signal degradation.
IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION
(2021)
Article
Engineering, Electrical & Electronic
Sungmin Cho, Ahmed Salim, Ho-Jin Song
Summary: This study demonstrates two-dimensional beam-steering of an active lens at 19 GHz using simple grid bias lines, achieving a wide range of beam scanning and improved power consumption efficiency through a small number of vertical and horizontal bias lines for MxN unit cells.
IEEE TRANSACTIONS ON VEHICULAR TECHNOLOGY
(2021)
Article
Computer Science, Hardware & Architecture
Minkyu Sung, Sang-Rok Moon, Eon-Sang Kim, Sungmin Cho, Joon Ki Lee, Seung-Hyun Cho, Tetsuya Kawanishi, Ho-Jin Song
Summary: The paper comprehensively analyzes and compares various potential THz communications systems with a focus on photonics-based THz transmitters. The research indicates that optical and phase noise have a significant impact on system performance.
IEEE WIRELESS COMMUNICATIONS
(2021)
Proceedings Paper
Engineering, Electrical & Electronic
Chan-Gyu Choi, Hyun-Hak Jeong, Ho-Jin Song
Summary: The study introduces a THz waveguide packaging technique that allows a single chip to be coupled to multiple waveguide interfaces using on-chip probes, offering simple assembly and low loss power combining. Experimental results demonstrate flat insertion loss and return loss, with good inter-circuit isolation between CPWs across a wide frequency range. The transition loss per dipole antenna is estimated to be around 1 dB.
2021 IEEE MTT-S INTERNATIONAL MICROWAVE SYMPOSIUM (IMS)
(2021)
Article
Computer Science, Hardware & Architecture
Kyunghwan Kim, Kangseop Lee, Gibeom Shin, Seunghoon Lee, Hyeonuk Son, Sungmin Cho, Ho-Jin Song
Summary: The 66-79 GHz transmitter presented here, designed for radar and communication systems, features wideband operation and high linearity. Key technologies include stacked-FET power amplifier and phase-controlled push-push frequency quadrupler, enabling mid-range sensing and short-range data transmission performance.
IEEE SOLID-STATE CIRCUITS LETTERS
(2021)
Proceedings Paper
Computer Science, Hardware & Architecture
Ho-Jin Song
2020 IEEE WIRELESS COMMUNICATIONS AND NETWORKING CONFERENCE WORKSHOPS (WCNCW)
(2020)
Proceedings Paper
Engineering, Electrical & Electronic
Seunghoon Lee, Ho-Jin Song
2020 IEEE INTERNATIONAL SYMPOSIUM ON ANTENNAS AND PROPAGATION AND NORTH AMERICAN RADIO SCIENCE MEETING
(2020)
Proceedings Paper
Engineering, Electrical & Electronic
Sungmin Cho, Ho-Jin Song
2020 IEEE INTERNATIONAL SYMPOSIUM ON ANTENNAS AND PROPAGATION AND NORTH AMERICAN RADIO SCIENCE MEETING
(2020)