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- 2018
- GaN HEMTs
- Power amplifier
- Broadband power amplifier
- SC band
- Power combining
- concentrated capacitive load
- distribution of the complex current at the antenna
- broadband antenna
- standing wave voltage factor
- antenna gain factor
- Electronic Science and Technology
- Oles Honchar Dnipro National University
- University of Tehran
- Gdansk University of Technology
- V. N. Karazin Kharkiv National University
- Reykjavik University
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A broadband cavity enhanced absorption spectrometer for aircraft measurements of glyoxal, methylglyoxal, nitrous acid, nitrogen dioxide, and water vapor
摘要： We describe a two-channel broadband cavity enhanced absorption spectrometer (BBCEAS) for aircraft measurements of glyoxal (CHOCHO), methylglyoxal (CH3COCHO), nitrous acid (HONO), nitrogen dioxide (NO2), and water (H2O). The instrument spans 361–389 and 438–468 nm, using two light-emitting diodes (LEDs) and a single grating spectrometer with a charge-coupled device (CCD) detector. Robust performance is achieved using a custom optical mounting system, high-power LEDs with electronic on/off modulation, high-reflectivity cavity mirrors, and materials that minimize analyte surface losses. We have successfully deployed this instrument during two aircraft and two ground-based field campaigns to date. The demonstrated precision (2σ) for retrievals of CHOCHO, HONO and NO2 are 34, 350, and 80 parts per trillion (pptv) in 5 s. The accuracy is 5.8, 9.0, and 5.0 %, limited mainly by the available absorption cross sections.
关键词： broadband cavity enhanced absorption spectroscopy,water vapor,nitrous acid,methylglyoxal,aircraft measurements,glyoxal,nitrogen dioxide
更新于2025-09-09 09:28:46
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[IEEE 2018 15th Workshop on Positioning, Navigation and Communications (WPNC) - Bremen, Germany (2018.10.25-2018.10.26)] 2018 15th Workshop on Positioning, Navigation and Communications (WPNC) - 100 Gbps and beyond: Hardware in the Loop experiments with PSSS modulation using 230 GHz RF frontend
摘要： The terahertz frequency range provides abundant bandwidth (25GHz ~ 50 GHz) to achieve ultra-high-speed wireless communication and enables data rates up to and above 100 Gbps. Parallel Sequence Spread Spectrum (PSSS) is a physical layer (PHY) baseband technology which is suitable for ultra-high speed wireless communication since the receiver architecture is straightforward and can be implemented almost entirely in analog hardware. In this paper, a PSSS modulated signal at a chip rate of 20 Gcps with a spectral efficiency of 4 bit/s/Hz is transmitted using a 230 GHz RF-front-end operating in the linear range to achieve 80 Gbps. The PSSS transceiver models are implemented in MATLAB/Simulink. The PSSS transmitter generates the PSSS modulated symbols that are loaded into an Arbitrary Waveform generator (AWG) and are then transmitted using the available 230 GHz wireless frontend. A Real-Time Oscilloscope samples and stores the received signal. The PSSS receiver performs synchronization, channel estimation, and demodulation. For a coded data rate of 80 Gbps, a BER of 2.072?10-3 has been measured. Thus, PSSS modulation is the promising modulation technique to achieve a data rate up to or above 100 Gbps in the Terahertz domain
关键词： PSSS,100 Gbps,broadband receiver,THz,wireless,PHY layer,submillimeter-wave,Hardware-In-The-Loop
更新于2025-09-09 09:28:46
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A Case Study on the Bandwidth Broadening of a Skeletal Biconical Antenna
摘要： In the scope of Electromagnetism and its applications, antennas stand out for making the transmission and reception of radio waves feasible. The design of an antenna depends on the requirements of the intended application, which involve aspects related to the way it should radiate or receive radio waves, and also its behavior as a circuit element. Under this criterion, in particular, the antenna is regarded as an impedance, the response of which varies with frequency. Since the impedance of most of the antennas varies significantly with frequency, that is, it has narrowband response, designing broadband antennas usually requires additional effort. This article aims to provide a case study on the use of some of the simplest band broadening techniques for antennas. In particular, emphasis is given to the use of impedance matching networks based on LC filters, transformers and minor changes in the antenna structure, such as the use of parasitic elements. The biconical skeletal antenna is taken as reference structure, with results that show the efficacy of those techniques mainly when applied together.
关键词： broadband antennas,antennas,electromagnetism,biconical antenna,impedance matching
更新于2025-09-09 09:28:46
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Broadband Circularly Polarized Filtering Antennas
摘要： This paper consists of two parts. The first part presents a review of the recent development in broadband circularly polarized filtering antennas. The second part presents a novel design of broadband integrated filtering antenna based on eighth-mode SIW (EMSIW) resonators for rectenna applications. This work has three main novel contributions: (i) By adjusting the external quality factors and coupling coefficients of the resonators in this filtering antenna, optimum input impedance with a complex value can be realized within the filtering antenna. Thus there is no need for an external impedance matching network, which is usually required between the antenna and the rectifying circuits; (ii) Compared with traditional microstrip resonators, high-Q EMSIW cavities are used to increase antenna gain; (iii) The coupling gap between the EMSIW resonators also acts as the feeding structure of the radiator. So the feeding structures are all on the middle layer. The ground plane on the back side is a complete structure without any defects. This novel structure design improves front-to-back ratio to enhance the antenna receiving efficiency. To validate this method, two C-band circularly polarized integrated filtering antennas with an input impedance of 50 Ω and complex impedance are designed, simulated and fabricated. The measured results show that the operating frequency bandwidth of the proposed antennas is more than 14.5% at C band with the gain above 8 dBi. The 3 dB Axial Ratio (AR) bandwidth is larger than 8.5% and the front-to-back ratio is higher than 18 dB. Moreover, the proposed antenna with complex impedance is conjugate matched with the input impedance of a specific rectifying circuit at 5.8 GHz and harmonics suppression at the 2nd harmonic frequency is achieved.
关键词： filtering antenna,Broadband antenna,circularly polarized antenna,impedance match,rectenna
更新于2025-09-09 09:28:46
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DESIGN OF COMPACT RECONFIGURABLE BROADBAND BAND-STOP FILTER BASED ON A LOW-PASS FILTER USING HALF CIRCLE DGS RESONATOR AND MULTI-LAYER TECHNIQUE
摘要： This paper describes the design of a two-pole low-pass and band-stop ?lters. The low-pass structure is designed at the cuto? frequency of 2 GHz for the L-Band applications. This architecture uses half circle defected ground structure HCDGS instead full circle DGS resonator. Both the HCDGS shapes are etched in the ground plane and coupled via a substrate with a compensated capacitor. The rejection bandwidth of the LPF covers a large wideband spectrum. Therefore, the band suppression reaches more than 3f c. The ?lter is simulated and fabricated. The measured results are in good agreement with the full-wave simulated ones, showing the merits of compact size and sharp roll-o?. The multi-layer technique has been used in order to realize a transformation from low-pass behaviours to band-stop characteristics, keeping the same passband features. The new extracted band-stop topology is simulated and optimized using an RO4003 substrate with relative permittivity of 3.38 and thickness of h = 0.813 mm. The structure has a wide stopband with over 20 dB rejection from 3.5 GHz to 8.5 GHz. Such ?lters can be used for L-band and military applications.
关键词： compact,reconfigurable,broadband band-stop filter,half circle DGS resonator,low-pass filter,multi-layer technique
更新于2025-09-09 09:28:46
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A BROADBAND CPW-FED CIRCULARLY POLARIZED SQUARE SLOT ANTENNA FOR UHF RFID APPLICATIONS
摘要： A broadband CPW-fed circularly polarized square slot antenna for ultra-high-frequency (UHF) radio frequency identification (RFID) applications is proposed. It consists of a square slot embedded with a spur line along diagonal and an F-shaped feeding structure. The proposed antenna achieves an impedance bandwidth about 307 MHz (34.6% @886 MHz) and a 3 dB axial ratio (AR) bandwidth about 232 MHz (24.3% @954 MHz). The 3 dB AR beam-width is about 96 degrees over the UHF band of 840–960 MHz. The proposed reader antenna based on CPW structure is easy to integrate. With the symmetry and bidirectional radiation pattern, there are less readers needed in some applications, such as access control, than the reader with unidirectional pattern, which will definitely decrease the implemented cost. Therefore, this universal design with desired performance across the entire UHF RFID band (from 840 MHz to 960 MHz) can be applied to all the UHF RFID applications worldwide. Detailed considerations of the design and main parameters will be studied in this paper.
关键词： square slot antenna,UHF RFID,broadband,circularly polarized,CPW-fed
更新于2025-09-09 09:28:46
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22.1: Fabrication of Broadband Quarter Wave Plate by Combination of Two Retardation Films Using Coating Technique
摘要： Broadband quarter waveplate can be treated as a circular polarizer providing true dark in the display system. Broadband quarter wave plate consists of two waveplates with different alignment direction using coating technique is proposed and fabricated. The reflection spectrum shows a good dark state
关键词： Broadband waveplate,Photoalignment,Dark state
更新于2025-09-09 09:28:46
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[IEEE 2018 20th International Conference on Transparent Optical Networks (ICTON) - Bucharest (2018.7.1-2018.7.5)] 2018 20th International Conference on Transparent Optical Networks (ICTON) - The Social-Economic Impact of Fiber Broadband: A Hype or a Reality?
摘要： The social-economic impact of broadband has been studied extensively. The consensus is that basic broadband (from none or upgraded from 256 kbps to the order of 2 – 6 Mbps) indeed has positive impact on economic growth and performance in terms of e.g. GDP and employment. Nevertheless, studies on the social-economic impact of high-speed broadband access (20-30 Mbps and beyond) are far more controversial showing a mixed picture. In this paper, we investigated fiber broadband access impact on the employment rate, population evolution, reduced driving distance per capita and new company registrations at the municipality level in Sweden using multiple regression analysis. Based on the availability of historical fiber network deployment data, analyses can be carried out by regressing current values of social-economic indicators under study on the fiber penetration levels 4 years earlier, hence reverse causality in the regression analyses can be tackled effectively. Our results show that, given all the other significant factors remain the same and with at least 90% confidence interval, 10% increase of fiber broadband penetration would result in 0.17% population increase, 0.32% employment rate enhancement, 28.7 km reduced driving distance per capita per year, and one new company among 17857 inhabitants.
关键词： social-economic impact,causality,social-economic indicators,multiple regression analysis,municipality,fiber broadband penetration
更新于2025-09-09 09:28:46
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[IEEE 2018 43rd International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz2018) - Nagoya, Japan (2018.9.9-2018.9.14)] 2018 43rd International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz) - Bi-layer Metamaterial based Broadband Linear Polarization Converter under Two Coherent Beam Illumination
摘要： We demonstrate a bi-layer metamaterial structure with mirror symmetry that acts as a linear polarization converter under two-antisymmetric-beam illumination. Its high performance, including broad bandwidth, high transmittance and high efficiency, originates from the combination of two interference processes: the Fabry-Pérot-like cavity effect between two metallic patterned layers and coherent excitations of spatially separated subwavelength resonators. Terahertz (THz) experiments show good agreement with numerical simulations.
关键词： Fabry-Pérot-like cavity,broadband,THz experiments,linear polarization converter,high efficiency,bi-layer metamaterial,coherent excitations,high transmittance
更新于2025-09-09 09:28:46
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[IEEE 2018 IEEE Photonics Conference (IPC) - Reston, VA, USA (2018.9.30-2018.10.4)] 2018 IEEE Photonics Conference (IPC) - Modeling and Analysis of SOI Grating Coupler for Bio-sensing Applications
摘要： This work presents, analysis of SOI optical grating structure operating at 1310 nm wavelength. Power coupling analysis between optical source and grating structure is done. The maximum power coupling efficiency of 55.2% is achieved for 500nm grating pitch having 50% duty cycly on 220nm Si-layer.
关键词： Broadband wavelength,Injection angle,Grating coupler,Multi beam,bio-sensor
更新于2025-09-05 23:14:25