- 标题
- 摘要
- 关键词
- 实验方案
- 产品
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Optically reconfigurable planar monopole antenna for cognitive radio application
摘要： Frequency reconfigurable antenna is one of the important elements needed for cognitive radio application. Such antenna can be designed using highly resistive (HR) silicon (Si) operating as an optical switch. This letter presents a novel frequency reconfigurable planar monopole antenna suitable for cognitive radio application. The antenna is designed using HR Si working as an optical switch. The main idea behind the design of antenna is the redistribution of surface current on the antenna while changing the state of Si switches optically from high resistance to low resistance. The antenna is highly compact and uses only two switches for multiband reconfiguration. It is switchable on 1.9 GHz, 2.75 GHz, 3.7 GHz, 4.1 GHz, 4.6 GHz, 4.8 GHz, and 7.6 to 11 GHz frequency bands. Simulated and measured results are presented for the antenna. To the best of authors knowledge, this is the first multiband optically reconfigurable planar monopole antenna.
关键词： high-resistive (HR) silicon,optical excitation,low-resistive (LR) silicon,planar monopole antenna,cognitive radio,reconfigurable,multiband
更新于2025-09-23 15:22:29
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Experimental Demonstration of Subband Index Techniques for m-CAP in Short Range SI-POF Links
摘要： In this letter, novel spectrally-efficient subband index (SI) techniques have been developed for multiband carrierless amplitude and phase modulation (m-CAP). The subband index techniques transmit additional information bit on the index of the conventional m-CAP subbands. Experimental demonstrations are performed in a short range optical data link using step-index plastic optical fibre (SI-POF). The demonstrations show that the proposed techniques enable flexibility in design and significantly improve the power/spectral efficiency of the conventional m-CAP.
关键词： step-index plastic optical fibre (SI-POF),multiband carrierless amplitude phase modulation (m-CAP),index modulation,Optical communication
更新于2025-09-23 15:21:21
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COMPACT CPW-FED MULTIBAND ANTENNA FOR TD-LTE/WLAN/WIMAX APPLICATIONS
摘要： A compact coplanar waveguide fed multiband antenna is proposed and investigated. The proposed antenna consists of a rectangular radiating patch and dual meander strips with a defected ground plane. The size of the fabricated prototype is 28.3 × 24 × 1.59 mm3. The proposed antenna radiates at three di?erent resonant modes, which cover 2.29–2.63 GHz, 3.26–3.96 GHz, and 4.97–6.10 GHz. The proposed antenna can be used for TD-LTE 2300/2500 (2.305–2.4 GHz), WLAN (2.4–2.4835 GHz and 5.15–5.875 GHz) and WiMAX (2.3–2.4 GHz and 3.3–3.7 GHz) applications. The proposed antenna exhibits an omnidirectional radiation pattern in the H-plane and a dipole-like radiation pattern in the E-plane. The measured peak gains are 2.64/4.48/6.08 dBi at 2.4/3.5/5.5 GHz operating frequency bands, respectively.
关键词： TD-LTE,WLAN,CPW-fed,WiMAX,multiband antenna,compact
更新于2025-09-23 15:21:21
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[IEEE 2018 IEEE Photonics Conference (IPC) - Reston, VA, USA (2018.9.30-2018.10.4)] 2018 IEEE Photonics Conference (IPC) - Experimental Demonstration of User Allocation in a Subcarrier Multiplexing-Based Multiuser LiFi System
摘要： We want to allocate the users to the optimal subcarriers in visible light communication. Allocation algorithms adapted from fiber-optic and implemented in an experimental setup attain a deviation from the bit rate target inferior to 5 percent for 11 users.
关键词： subcarrier multiplexing,multiuser,Indoor network,multiband CAP,LiFi,visible light communication
更新于2025-09-23 15:21:01
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[Lecture Notes in Electrical Engineering] Microelectronics, Electromagnetics and Telecommunications Volume 521 (Proceedings of the Fourth ICMEET 2018) || Bandwidth Enhancement of Circular Ring Fractal Antenna for Wireless Applications
摘要： A pentaband direct fed circular patch antenna with ring fractals is proposed in this paper. The design and analysis of proposed antenna are done by using Ansoft HFSS. To enhance the bandwidth of patch antenna, fractals are implemented. The proposed antenna is designed to four iterations on the circular patch, which covers WLANs and WiMAX applications. The impedance bandwidths achieved are 390 MHz, 330 MHz, 190 MHz, 380 MHz, and 860 MHz at the resonant frequencies 1.68 GHz, 2.49 GHz, 2.73 GHz, 3.94 GHz, and 5.65 GHz, respectively. The corresponding peak gains at their resonant frequencies are 2.789 dB, 3.574 dB, 4.658 dB, 3.427 dB, and 4.803 dB respectively. The designed antenna is used for S-band and C-band applications.
关键词： Ring fractal,Circular patch,Multiband
更新于2025-09-23 15:21:01
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A highly independent multiband bandpass filter using a multi-coupled line stub-SIR with folding structure
摘要： The main problem in designing a multiband bandpass filter (BPF) is making each passband response highly independent, where each bandwidth of multiband BPF can be controlled and adjusted separately. To overcome this problem, this paper proposes a highly independent multiband BPF based on a multicoupled line stub-SIR with a folding structure. The proposed multiband BPF is constructed as a multicoupled line to generate a highly independent inter passband. Moreover, the multiband performance is produced separately and independently by using three sets of resonators: resonator A1/A2 (RA1 and RA2), resonator B1/B2 (RB1 and RB2), and resonator C1/C2 (RC1 and RC2). The three passband frequencies can be independently arranged and designed. To miniaturize the multiband BPF, a folding structure is also proposed. As a result, the multiband BPF has a compact size that is reduced by over 61.29 % compared to previous structures. The even-odd excitation model and the equivalent circuit model are used to analyze the multiband BPF structure. This BPF is designed for GPS applications at 1.57 GHz, WCDMA (3G) at 1.8 GHz, WLAN (WiFi) at 2.4 GHz, LTE (4G) at 2.6 GHz, and 5G communication at 3.5 GHz. To evaluate and validate the proposed structure of the multiband BPF, the circuits are fabricated and tested. The simulated and measured results of the multiband BPF show good agreement. In conclusion, the proposed multiband BPF structure has a highly independent inter passband response and a compact size.
关键词： highly independent,Compact,multiband BPF,folding structure
更新于2025-09-23 15:19:57
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Demonstration of a Hybrid FSO/VLC Link for the Last Mile and Last Meter Networks
摘要： In this paper, a hybrid free-space optical and visible light communication (FSO/VLC) system was experimentally demonstrated as a solution to overcome the last mile and last meter access networks bandwidth bottleneck. We evaluate the system performance of a multiband carrier-less amplitude and phase (m-CAP) modulation scheme for a range of FSO/VLC link lengths and m-CAP parameters (i.e., the roll-off factor of the ?lters and a number of subcarriers) in terms of the data rate Rb (i.e., spectral ef?ciency). We show that for the con?guration with a 1 m VLC link the 10-CAP offers more than a 40 % improvement in the measured Rb compared to 2-CAP for the same bit error rate target. The Rb penalty due to the extension of a VLC link span from 1 m to 3 m reaches to 12.6 Mb/s for the 10-CAP scheme (i.e., ～39 % degradation in Rb). To fully cover all aspects of the hybrid FSO/VLC system, we also investigate the atmospheric turbulence effect on the 500 m FSO link n of 2.4×10?15 m?2/3 where Rb is decreased by 30 % for the refractive index structure parameter C2 compared to a clear channel condition.
关键词： multiband carrier-less amplitude and phase modulation,Visible light communication,free space optics
更新于2025-09-23 15:19:57
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Fractal Analysis - Applications in Physics, Engineering and Technology || Fractals in Antennas and Metamaterials Applications
摘要： Recently, telecommunications systems have been requiring more advanced features in the design and operation. Among others a smaller size of devices, which can be integrated for multiple mobile communications systems, applied in one user's device board, such as PDA or smartphone. Moreover, the cost of mass production should be minimized as much as possible. To meet part of that request, the antennas of these devices should have small size, lower weight, operating in multiple frequency bands and/or be broadband. There are many research methods to achieve this goal, one of which is using the fractal geometries for the shape of antenna elements. In recent years, there are many fractal shapes that have been proposed for such applications, and the designed antennas have significantly improved antenna features such as smaller size, operating in multi-frequency bands, with improved power gain and efficiency. In recent years, the new approach for modern antenna the metamaterials, MTM, is adopted, and sometimes that based on the fractal geometry is adopted.
关键词： fractal geometries,fractal antenna,antenna array,efficiency,fractal dimension,IFS,metamaterials,power gain,MTM,multiband,antenna elements,compact size
更新于2025-09-19 17:15:36
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[IEEE 2018 Asia Communications and Photonics Conference (ACP) - Hangzhou, China (2018.10.26-2018.10.29)] 2018 Asia Communications and Photonics Conference (ACP) - Photonics-based Multiband Radar Applying an Optical Frequency Sweeping Comb and Photonic Dechirp Receiving
摘要： A photonics-based multiband radar is proposed based on an optical frequency sweeping comb and photonic dechirp receiving. The proposed radar has a simple structure, and it is capable to simultaneously generate and process multiple in different frequency bands. Besides, the radar receiver can achieve fast or real-time signal processing with low-speed electronics. In the proof-of-concept experiment, a photonics-based dual-band radar working in K-band (19-22 GHz) and Ka-band (34-37 GHz) is demonstrated with a bandwidth of 3 GHz in each band and a sampling rate of 100 MSa/s in the receiver.
关键词： dechirp processing,multiband radar,optical frequency comb,microwave photonics
更新于2025-09-19 17:15:36
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Compact circularly polarized metaresonator‐enabled deca‐band antenna
摘要： In this article, a circularly polarized small-sized deca-band monopole antenna is proposed and investigated. The proposed antenna consists of gun-shaped monopole radiator and split-ring resonator (SRR) array-loaded partial ground plane present on the top and bottom sides of the substrate, respectively. The antenna is excited by a microstrip line feed and in order to get varied multiband operation with circular polarization, several unique configurations of SRRs are employed as metaresonators. Using the approach of combining resonances of metaresonators and monopole radiator, dual-, triple-, hexa-, and deca-band operations can be achieved. The permittivity and permeability of the composite metaresonator structure made of SRRs are extracted to illustrate the working principle of the designed multiband antenna. The proposed multiband antenna covers long-term evolution, WLAN, WiMAX, bluetooth, satellite digital audio radio system (SDARS), radio altimeter, and satellite single communication C-band applications, on a multifunctional device, much needed in the fast-growing wireless industry. The antenna is fabricated on a 40 × 47 × 1.5748 mm3 RT Duroid 5880 substrate, and simulations were carried out with the help of the tool Ansys HFSS. The simulated and measured results are in good agreement.
关键词： metaresonator,multiband,circularly polarized,split ring,monopole
更新于2025-09-19 17:13:59