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The arrival angular profile prediction formula at base station (BS) is necessary in order to assess spatial processing technologies such as MIMO (Multi-Input Multi-Output) techniques. In previous works, we proposed an empirical arrival angular profile model at BS in macro cells (Macro-cell arrival angular profile model) where the BS height is higher than the average building height in its coverage...
This paper reports on the methodology of estimating tropospheric ducting effects from the received signal quality of terrestrial digital TV services. The results are correlated with the variation of the modified refractivity of the atmosphere as a function of height, clearly indicating the formation of the tropospheric ducts at the time of the measurement. Prediction of the received signal enhanced...
We examine the empirical prediction of terrestrial radio link clear-air fading, and the use of parameters from surface weather stations as an alternative to, or in combination with, numerical weather prediction (NWP) reanalysis parameters. We achieve desired prediction accuracy from models employing only climatic data from surface measurements, which can be further improved with additional NWP parameters.
Long-term rain attenuation statistics and variations are discussed using Ku band satellite signal observations conducted at Osaka Electro-Communication University in Neyagawa, Japan, from 1988 to 2015. The yearly cumulative time percentages of Ku band attenuation indicate fairly large variations which amount to about 20% around the mean values. Besides the yearly rainfall rate statistics, these variations...
The effects of site diversity techniques on Ku-band rain attenuation are investigated using two sets of simultaneous satellite signal observations, which have been conducted among Osaka Electro-Communication University (OECU) in Neyagawa, Kyoto University in Uji, and Shigaraki MU Observatory in Koga for about past nine years, and among the headquarters of OECU in Neyagawa and their other facilities...
Slots are cut into the arms of an Archimedean spiral antenna in order to generate a stop band. The center frequency of the stop band is determined by the slot resonance, which occurs when the slot length is close to one-quarter wavelength. It is found that the gain drastically drops at the center frequency of the stop band. It is also found that the radiation characteristics outside the stop band...
The various conical wall edge structure design of multiband spiral antenna for side lobe improvement is considered. The various edge shapes were designed and evaluated. The axial ratio of spiral antenna with a novel edge structure was not almost changed to compare with the conventional spiral antenna with only conical wall. The measured back lobes of spiral antenna with an elliptical dual edge and...
A wideband circularly polarized (CP) strip-helical dipole antenna is presented in this paper. Two tapered strip-helixes with one turn are placed over a ground plane and symmetric to each other with respect to the Z-Axis. Each of them is respectively fed with same magnitude and phase difference of 180° thus the whole radiator works as a helical dipole. Numerical results show that the proposed strip-helical...
A low profile dual-polarized unidirectional wideband antenna based on two crossed magneto-electric dipoles is proposed. The antenna consists in folding the radiating element, the height of the radiation element is reduced to 0.11λ0 where λ0 is the wavelength at the lowest operation frequency for a standing wave ratio (SWR) <2 corresponding to a reduction factor of 37%. The antenna has been prototyped...
3D-printing has been used for rapidly prototyping a low-cost and light-weight dielectric zone plate Fresnel lens (FL). This lens was comprised of four dielectric zones and they were fabricated in one process with the tailored permittivities. Measurements show that this lens provides 7.3 to 12.8 dB gain enhancement over the frequency band from 8 to 12 GHz.
This paper presents a novel 3D-printed low-cost, light weight, broadband and high gain planar graded index (GRIN) lens. The GRIN lens was designed to transform spherical wavefronts into planar wavefronts which can be used for antenna gain enhancement. Fused deposition modelling 3D-printing was used to fabricate the lens in a single process with bespoke radially varying relative permittivity. Measured...
A 3D printed reflectarray antenna is designed for operation at 60 GHz. The design methodology is based on the all-metal reflectarray approach in which the required reflection phase distribution is achieved by controlling the depths of the rectangular grooves on the reflecting surface. The metallic grooved surface is conveniently fabricated using 3D printing technology followed by metallization via...
A near isotropic 3D printed antenna on a cubic structure is presented in this work for the first time. The fully inkjet printed antenna has been realized by a unique combination of 3D inkjet printing of dielectric and 2D inkjet printing of metal. The antenna comprises a 1.5λ0 dipole that is wrapped around the cube to achieve a near isotropic radiation pattern. The cube measures 2 cm × 2 cm × 2 cm,...
A novel polarization reconfigurable leaky-wave (LW) antenna based on half-mode substrate integrated waveguide (HMSIW) is presented. Compared with SIW antenna, HMSIW reduces the volume of antenna a lot with similar capability [1]. The proposed antenna consists of a pair of symmetrical +45°/−45° linearly polarized leaky lines. By changing the means of excitation, six different polarization states including...
A ±45° slant polarization (SP) reconfigurable omnidirectional antenna and a circular polarization (CP) reconfigurable omnidirectional antenna are proposed. 16 PIN diodes are employed for the ±45° SP reconfigurable omnidirectional antenna while 8 PIN diodes are used for the CP reconfigurable omnidirectional antenna. Simulation and experimental results are demonstrated.
This paper presents a switched-beam antenna for LTE/WWAN operation in Small Cell application. The proposed antenna consists of 5 sets high gain dual-polarized dipole antennas, and integrated a switching network circuit to form multiple beams to improve wireless communication performance.
In this paper, an antenna with reconfigurable radiation pattern in H-plan at 2.45 GHz for high power applications is presented. It is based on a 3 slots array in E-plane covered partially with two mobile metallic flaps in order to reduce their length and in consequence they ensure the mechanical reconfiguration pattern in H-plane. The power distribution of the array is ensured with a power splitter...
This work investigates applications of graphene in reconfigurable antennas. A reconfigurable graphene metamaterials array is designed and characterized, and further applied to design reconfigurable hybrid antenna. Simulation results have proved reconfigurable antenna radiation pattern. This work proves graphene is promising in designing flexible antenna system with both high radiation efficiency and...
This paper presents the design and realisation of a compact reconfigurable quad-/dual-band microwave antenna, which has been implemented based on a novel quad-mode slotline resonator (SLR). The coplanar waveguide (CPW) feeding structure has also been designed in detail in order to be able to optionally function under both the weakly-or strongly-coupling conditions. Under the weakly-coupling condition,...
This paper presents measured performance of 15 GHz beam adjustable microstrip antenna arrays (BA-MSAAs). The BA-MSAA consists of a central patch element fed by a feeding line and two parasitic patches with a variable reactance circuit (VRC) adjacent to the center patch. Radiation pattern of the BA-MSAA is controlled by reactance values of the VRCs. In order to evaluate beam-shaping performance of...
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