A down-conversion mixer and an up-conversion mixer for 2.4GHz WLAN transceivers are presented.The down-conversion mixer uses a class-AB input stage to get high linearity and to realize input impedance matching and sin...A down-conversion mixer and an up-conversion mixer for 2.4GHz WLAN transceivers are presented.The down-conversion mixer uses a class-AB input stage to get high linearity and to realize input impedance matching and single-ended to differential conversion.The mixers are implemented in 0.18μm CMOS process.The measured results are given to show their performance.展开更多
The paper describes a low-power CMOS voltage-controlled oscillator (VCO) with dual-band local oscillating (LO) signal outputs for 5/2.5-GHz wireless local area network (WLAN) transceivers. The VCO is based on an on-ch...The paper describes a low-power CMOS voltage-controlled oscillator (VCO) with dual-band local oscillating (LO) signal outputs for 5/2.5-GHz wireless local area network (WLAN) transceivers. The VCO is based on an on-chip symmetrical spiral inductor and a differential varactor. The 2.5-GHz quadrature LO signals are generated using the injection-locked frequency divider (ILFD) technique. The ILFD structure is similar to the VCO structure with its wide tracking range. The design tool ASITIC was used to optimize all on-chip symmetrical inductors. The power consumption was kept low with differential LC tanks and the ILFD technique. The circuit was implemented in a 0.18-μm CMOS process. Hspice and SpectreRF simulations show the proposed circuit could generate low phase noise 5/2.5-GHz dual band LO signals with a wide tuning range. The 2.5-GHz LO signals are quadrature with almost no phase and amplitude errors. The circuit consumes less than 5.3 mW in the tuning range with a power supply voltage of 1.5 V. The die area is only 1.0 mm×1.0 mm.展开更多
We present a novel coherent transceiver for optical differential phase-shift keying/differential quadrature phase-shift keying （DPSK/DQPSK） signals based on heterodyne detection and electrical delay interferometer. ...We present a novel coherent transceiver for optical differential phase-shift keying/differential quadrature phase-shift keying （DPSK/DQPSK） signals based on heterodyne detection and electrical delay interferometer. A simulation framework is provided to predict a theoretical sensitivity level for the reported scheme. High sensitivity of –45.18 dBm is achieved for 2.5-Gb/s return-to-zero （RZ）-DPSK signal, and high sensitivities of –36.83 dBm （I tributary） and –35.90 dBm （Q tributary） are observed for 2.5-GBaud/s RZ-DQPSK signal in back-to-back configuration. Transmission for both signals over 100 km is also investigated. Experimental results are discussed and analyzed.展开更多
With the explosion of wireless data rates,the terahertz(THz)band(0.1–10 THz)is envisioned as a promising candidate to break the existing bandwidth bottleneck and satisfy the ever-increasing capacity demand.The THz wi...With the explosion of wireless data rates,the terahertz(THz)band(0.1–10 THz)is envisioned as a promising candidate to break the existing bandwidth bottleneck and satisfy the ever-increasing capacity demand.The THz wireless communications feature a number of attractive properties,such as potential terabit-per-second capacity and high energy efficiency.In this paper,an overview on the state-of-the-art THz communications is studied,with a special focus on key technologies of THz transceivers and THz communication systems.The recent progress on both electronic and photonic THz transmitters are presented,and then the THz receivers operating in direct-and heterodyne reception modes are individually surveyed.Based on the THz transceiver schemes,three kinds of THz wireless communication systems are reviewed,including solid-state electronic systems,photonics-assisted systems and all-photonics systems.The prospective key enabling technologies,corresponding challenges and research directions for lighting up high-speed THz communication systems are discussed as well.展开更多
A review on Terahertz end-to-end systems with an emphasis on integrated approaches is presented.Four major catalogs of THz integrated systems,including THz communication systems,THz imaging systems,THz radars,and THz ...A review on Terahertz end-to-end systems with an emphasis on integrated approaches is presented.Four major catalogs of THz integrated systems,including THz communication systems,THz imaging systems,THz radars,and THz spectroscopy systems,are reviewed in this article.The performance of integrated systems is compared with non-integrated solutions,followed by a discussion on the trend in future research avenues and applications.展开更多
In this paper,a general scheme in digital self-interference cancellation at baseband for zero-IF full-duplex transceivers is presented. We model the self-interference signals specifically with only the nonlinear disto...In this paper,a general scheme in digital self-interference cancellation at baseband for zero-IF full-duplex transceivers is presented. We model the self-interference signals specifically with only the nonlinear distortion signals falling in receiving band considered. A joint estimation algorithm is proposed for compensating the time delay and frequency offset taking into account the IQ amplitude and phase imbalances from mixers. The memory effect and nonlinear distortion are adaptively estimated by the de-correlated normalized least mean square(DNLMS) algorithm. Numerical simulation results demonstrate that the proposed self-interference cancellation scheme can efficiently compensate the self-interference and outperform the existing traditional solutions.展开更多
The in-phase and quadrature-phase imbalance (IQI) is one of the major radio frequency impairments existing in orthogonal frequency division multiplexing (OFDM) systems with direct-conversion transceivers. During the t...The in-phase and quadrature-phase imbalance (IQI) is one of the major radio frequency impairments existing in orthogonal frequency division multiplexing (OFDM) systems with direct-conversion transceivers. During the transmission of the communication signal, the impact of IQI is coupled with channel impulse responses (CIR), which makes the traditional channel estimation schemes ineffective. A decoupled estimation scheme is proposed to separately estimate the frequency-dependent IQI and wireless channel. Firstly, the generalized channel model is built to separate the parameters of IQI and wireless channel. Then an iterative estimation scheme of frequency-dependent IQI is designed at the initial stage of communication. Finally, based on the estimation result of IQI, the least square algorithm is utilized to estimate the channel-related parameters at each time of channel variation. Compared with the joint estimation schemes of IQI and channel, the proposed decoupled estimation scheme requires much lower training overhead at each time of channel variation. Simulation results demonstrate the good estimation performance of the proposed scheme.展开更多
The Ultra-WideBand(UWB) technique, which offers good energy efficiency, flexible data rate, and high ranging accuracy, has recently been recognized as a revived wireless technology for short distance communication.Thi...The Ultra-WideBand(UWB) technique, which offers good energy efficiency, flexible data rate, and high ranging accuracy, has recently been recognized as a revived wireless technology for short distance communication.This paper presents a brief overview of two UWB techniques, covering Impulse-Radio UWB(IR-UWB) and FrequencyModulation UWB(FM-UWB) methods. The link margin enhancement technique, Very-WideBand(VWB), and power consumption reducing technique, chirp UWB, are also introduced. Then, several potential applications of IR-UWB with transceiver architectures are addressed, including high data rate proximity communication and secure wireless connectivity. With fine-ranging and energy-efficient communication features, the UWB wireless technology is highly promising for secure mobile Internet of Things(IoT) applications.展开更多
An optical transceiver with a novel optical subassembly structure is proposed in this paper, which achieves high coupling efficiency and low assembly difficulty. The proposed optical transceiver consumes 0.9 W power a...An optical transceiver with a novel optical subassembly structure is proposed in this paper, which achieves high coupling efficiency and low assembly difficulty. The proposed optical transceiver consumes 0.9 W power and retains a small size of 28 mmx16 mmx3 mm. The fabrication process of the silicon substrate and the assembly process of the optical transceiver are demonstrated in details. Moreover, the optical transceiver is measured in order to verify its transmission performance. The clear eye diagrams and the low bit error rate （BER） less than 1013 at 10 Gbit/s per channel show good transmission characteristics of the designed optical transceiver.展开更多
An integrated low power CMOS VCO and its divide by 2 dividers for WLAN transceivers are presented.The VCO is based on on chip symmetrical spiral inductor and differential diode and the divide by 2 dividers are b...An integrated low power CMOS VCO and its divide by 2 dividers for WLAN transceivers are presented.The VCO is based on on chip symmetrical spiral inductor and differential diode and the divide by 2 dividers are based on the ILFD technique.Due to differential LC tanks and ILFD techniques,power consumption is low.The circuit is implemented in a 0 18μm CMOS process.Measurements show the proposed circuit could produce 3 6/1 8GHz dual band LO signals with a wide tuning range and low phase noise.1 8GHz LO signals are quadrature.It consumes 5mA at V DD =1 5V.The size of die area is only 1 0mm×1 0mm.展开更多
文摘A down-conversion mixer and an up-conversion mixer for 2.4GHz WLAN transceivers are presented.The down-conversion mixer uses a class-AB input stage to get high linearity and to realize input impedance matching and single-ended to differential conversion.The mixers are implemented in 0.18μm CMOS process.The measured results are given to show their performance.
文摘The paper describes a low-power CMOS voltage-controlled oscillator (VCO) with dual-band local oscillating (LO) signal outputs for 5/2.5-GHz wireless local area network (WLAN) transceivers. The VCO is based on an on-chip symmetrical spiral inductor and a differential varactor. The 2.5-GHz quadrature LO signals are generated using the injection-locked frequency divider (ILFD) technique. The ILFD structure is similar to the VCO structure with its wide tracking range. The design tool ASITIC was used to optimize all on-chip symmetrical inductors. The power consumption was kept low with differential LC tanks and the ILFD technique. The circuit was implemented in a 0.18-μm CMOS process. Hspice and SpectreRF simulations show the proposed circuit could generate low phase noise 5/2.5-GHz dual band LO signals with a wide tuning range. The 2.5-GHz LO signals are quadrature with almost no phase and amplitude errors. The circuit consumes less than 5.3 mW in the tuning range with a power supply voltage of 1.5 V. The die area is only 1.0 mm×1.0 mm.
基金supported in part by the National "973" Program of China (No. 2011CB301702)the National Natural Science Foundation of China (No. 61001121,61006041, 60736036, and 60932004)the Fundamental Research Funds for the Central Universities
文摘We present a novel coherent transceiver for optical differential phase-shift keying/differential quadrature phase-shift keying （DPSK/DQPSK） signals based on heterodyne detection and electrical delay interferometer. A simulation framework is provided to predict a theoretical sensitivity level for the reported scheme. High sensitivity of –45.18 dBm is achieved for 2.5-Gb/s return-to-zero （RZ）-DPSK signal, and high sensitivities of –36.83 dBm （I tributary） and –35.90 dBm （Q tributary） are observed for 2.5-GBaud/s RZ-DQPSK signal in back-to-back configuration. Transmission for both signals over 100 km is also investigated. Experimental results are discussed and analyzed.
基金supported by the National Key Research and Development Program of China(2020YFB1805700,2018YFB1801500&2018YFB2201700)the Natural National Science Foundation of China under Grant 61771424the Natural Science Foundation of Zhejiang Province under Grant LZ18F010001 and Zhejiang Lab(no.2020LC0AD01).
文摘With the explosion of wireless data rates,the terahertz(THz)band(0.1–10 THz)is envisioned as a promising candidate to break the existing bandwidth bottleneck and satisfy the ever-increasing capacity demand.The THz wireless communications feature a number of attractive properties,such as potential terabit-per-second capacity and high energy efficiency.In this paper,an overview on the state-of-the-art THz communications is studied,with a special focus on key technologies of THz transceivers and THz communication systems.The recent progress on both electronic and photonic THz transmitters are presented,and then the THz receivers operating in direct-and heterodyne reception modes are individually surveyed.Based on the THz transceiver schemes,three kinds of THz wireless communication systems are reviewed,including solid-state electronic systems,photonics-assisted systems and all-photonics systems.The prospective key enabling technologies,corresponding challenges and research directions for lighting up high-speed THz communication systems are discussed as well.
文摘A review on Terahertz end-to-end systems with an emphasis on integrated approaches is presented.Four major catalogs of THz integrated systems,including THz communication systems,THz imaging systems,THz radars,and THz spectroscopy systems,are reviewed in this article.The performance of integrated systems is compared with non-integrated solutions,followed by a discussion on the trend in future research avenues and applications.
基金supported in part by the National Natural Science Foundation of China(No.61601027)
文摘In this paper,a general scheme in digital self-interference cancellation at baseband for zero-IF full-duplex transceivers is presented. We model the self-interference signals specifically with only the nonlinear distortion signals falling in receiving band considered. A joint estimation algorithm is proposed for compensating the time delay and frequency offset taking into account the IQ amplitude and phase imbalances from mixers. The memory effect and nonlinear distortion are adaptively estimated by the de-correlated normalized least mean square(DNLMS) algorithm. Numerical simulation results demonstrate that the proposed self-interference cancellation scheme can efficiently compensate the self-interference and outperform the existing traditional solutions.
基金supported by the National Natural Science Foundation of China(6140123261471200+4 种基金6150124861501254)the China Postdoctoral Science Foundation(2014M561692)the Jiangsu Province Postdoctoral Science Foundation(1402087C)the NUPTSF(NY213063)
文摘The in-phase and quadrature-phase imbalance (IQI) is one of the major radio frequency impairments existing in orthogonal frequency division multiplexing (OFDM) systems with direct-conversion transceivers. During the transmission of the communication signal, the impact of IQI is coupled with channel impulse responses (CIR), which makes the traditional channel estimation schemes ineffective. A decoupled estimation scheme is proposed to separately estimate the frequency-dependent IQI and wireless channel. Firstly, the generalized channel model is built to separate the parameters of IQI and wireless channel. Then an iterative estimation scheme of frequency-dependent IQI is designed at the initial stage of communication. Finally, based on the estimation result of IQI, the least square algorithm is utilized to estimate the channel-related parameters at each time of channel variation. Compared with the joint estimation schemes of IQI and channel, the proposed decoupled estimation scheme requires much lower training overhead at each time of channel variation. Simulation results demonstrate the good estimation performance of the proposed scheme.
基金supported in part by the National Natural Science Foundation of China (No. 61774092)。
文摘The Ultra-WideBand(UWB) technique, which offers good energy efficiency, flexible data rate, and high ranging accuracy, has recently been recognized as a revived wireless technology for short distance communication.This paper presents a brief overview of two UWB techniques, covering Impulse-Radio UWB(IR-UWB) and FrequencyModulation UWB(FM-UWB) methods. The link margin enhancement technique, Very-WideBand(VWB), and power consumption reducing technique, chirp UWB, are also introduced. Then, several potential applications of IR-UWB with transceiver architectures are addressed, including high data rate proximity communication and secure wireless connectivity. With fine-ranging and energy-efficient communication features, the UWB wireless technology is highly promising for secure mobile Internet of Things(IoT) applications.
基金supported by the National High Technology Research and Development Program of China(No.2015AA016904)
文摘An optical transceiver with a novel optical subassembly structure is proposed in this paper, which achieves high coupling efficiency and low assembly difficulty. The proposed optical transceiver consumes 0.9 W power and retains a small size of 28 mmx16 mmx3 mm. The fabrication process of the silicon substrate and the assembly process of the optical transceiver are demonstrated in details. Moreover, the optical transceiver is measured in order to verify its transmission performance. The clear eye diagrams and the low bit error rate （BER） less than 1013 at 10 Gbit/s per channel show good transmission characteristics of the designed optical transceiver.
文摘An integrated low power CMOS VCO and its divide by 2 dividers for WLAN transceivers are presented.The VCO is based on on chip symmetrical spiral inductor and differential diode and the divide by 2 dividers are based on the ILFD technique.Due to differential LC tanks and ILFD techniques,power consumption is low.The circuit is implemented in a 0 18μm CMOS process.Measurements show the proposed circuit could produce 3 6/1 8GHz dual band LO signals with a wide tuning range and low phase noise.1 8GHz LO signals are quadrature.It consumes 5mA at V DD =1 5V.The size of die area is only 1 0mm×1 0mm.
