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- 摘要
- 关键词
- 实验方案
- 产品
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[IEEE 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Chicago, IL, USA (2019.6.16-2019.6.21)] 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Synchrotron and optical probing of hybrid organic-inorganic perovskite halides for photovoltaics
摘要： Supporting high data rate wireless connectivity among wearable devices in a dense indoor environment is challenging. This is primarily due to bandwidth scarcity when many users operate multiple devices simultaneously. The millimeter-wave (mmWave) band has the potential to address this bottleneck, thanks to more spectrum and less interference because of signal blockage at these frequencies. In this paper, we explain the potential and challenges associated with using mmWave for wearable networks. To provide a means for concrete analysis, we present a system model that admits easy analysis of dense, indoor mmWave wearable networks. We evaluate the performance of the system while considering the unique propagation features at mmWave frequencies, such as human body blockages and re?ections from walls. One conclusion is that the non-isotropy of the surroundings relative to a reference user causes variations in system performance depending on the user location, body orientation, and density of the network. The impact of using antenna arrays is quanti?ed through analytic closed-form expressions that incorporate antenna gain and directivity. It is shown that using directional antennas, positioning the transceiver devices appropriately, and orienting the human user body in certain directions depending on the user location result in gigabits-per-second achievable ergodic rates for mmWave wearable networks.
关键词： personal communication networks,wearable computers,signal to noise ratio,Millimeter wave communication,performance analysis,analytic models,indoor communication,internet of things,virtual reality
更新于2025-09-23 15:19:57
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[Institution of Engineering and Technology 12th European Conference on Antennas and Propagation (EuCAP 2018) - London, UK (9-13 April 2018)] 12th European Conference on Antennas and Propagation (EuCAP 2018) - Novel Wideband Omnidirectional Monopole Antenna for Indoor Communication Environment
摘要： In this paper, a wideband omnidirectional monopole antenna for indoor communication environment is proposed. To achieve good omnidirectional radiation of the antenna at target frequency band, two parasitic elements are printed near the elliptical monopole patch. Besides, another patch which has the same size is printed on the bottom of substrate to increase antenna gain and avoid dielectric loss. Simulated and measured results validated the usefulness of the proposed antenna. The measured impedance bandwidth of the antenna with optimal parameters is from 3.2 GHz to 7.4 GHz for return loss < -10 dB. Moreover, the gain varies from 2.7 dBi to 3.4 dBi in 4 ~ 7 GHz and the uniformity of radiation pattern in omnidirectional radiation plane (H-plane) is limited to 3.9 dB in 4 ~ 7 GHz. Results mentioned above means the antenna can achieve a stable work in indoor communication environment.
关键词： monopole antenna,indoor communication,omnidirectional radiation
更新于2025-09-23 15:19:57
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Millimeter-wave Air-filled Slot Antenna with Conical Beam Based on Bulk Silicon MEMS Technology
摘要： In this communication, a millimeter-wave (mm-wave) air-filled slot antenna with a conical beam at 60 GHz is proposed. The antenna is suitable to be integrated with various IC systems mainly because it is designed and fabricated based on bulk silicon MEMS technology. The whole structure is composed of an antenna part and a waveguide to SIW converter. In the antenna part, four meander slots are arranged annularly and excited by a square air cavity. The conical radiation pattern benefits from the out-phase E field excited on slots. An operating bandwidth of 2.17% for S11 < -10 dB and a conical beam peak gain of 3.21 dBi are achieved. The proposed antenna shows its potentials in mm-wave indoor communication.
关键词： IC integration,slot antenna,Millimeter wave,indoor communication,conical beam,bulk silicon MEMS technology
更新于2025-09-16 10:30:52
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Design and implementation of LED-LED indoor visible light communication system
摘要： This paper investigates the experimental performance of LEDs as both photo-emitter and photoreceiver. In this work LED-LED link is established using BJT and MOSFET based drive circuits at transmitting side and resistor driver operated in photo-conductive mode is used at the receiver side. The LED response as transmitter and receiver is investigated at different operating frequencies with the distance of up to 20 cm and the data rate of 1 Mbps. The SNR values of 8 dB and 11 dB are obtained using BJT and MOSFET drivers respectively at a distance of 20 cm. Furthermore, six different color LEDs are tested on both sides of transceiver to determine the best performing pair. It is observed that the red color LEDs have good responses as a photodiode due to its long wavelength in the visible spectrum. However their performance is significantly effected by ambient noise. Moreover, the responsivity of the Red color LED operated as photoreceiver with respect to different biasing voltages is also experimentally measured and discussed.
关键词： Visible Light Communication,LED as Photo-receiver,LED as Photo-emitter,Indoor communication,Responsivity
更新于2025-09-12 10:27:22
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A Low-Cost Surveillance and Information System for Museum Using Visible Light Communication
摘要： This paper designed and implemented a low-cost surveillance and information system for museums with two new coding schemes using Visible Light Communication (VLC). For security, we use a key in place of the clock in the Manchester coding. For the enhanced data transfer, we use the unbalanced time duration for data one and zero. The prototype system was built with two low-cost microcontrollers, an LED, and linear light sensors. With 1 m distance in a dark environment, the maximum data transfer rate was roughly 1.93 kbits/s with a 10 Φ white LED. Under the dark-to-modest ambient brightness of up to 120 lux, the white LEDs were performed well in terms of the transmission to LEDs with different colors. The distance, compared experiments with flashlights reveal that our system can easily detect the prohibited use of flashlight. Experiments with the mobile phones’ flashlight also revealed that photographing with the flashlight would have a worse impact on arts than the continuous illumination. We also measured the distance between arts to avoid inevitable interference between illumination sources in neighbor.
关键词： Encoding,Indoor communication,Communication system security,Visible light communication
更新于2025-09-10 09:29:36