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In this paper, near-field antenna probe is designed for propagating spin wave spectroscopy (PSWS) measurement. We compare the meander-line and straight-line antenna probes. Effect of the dimension parameters of antenna probe on scattering parameter is investigated. Near-field distribution and radiation pattern of these two kinds of antenna probe are discussed. Also, the placement of antenna probe...
In this paper, Fermat-Archimedes spiral dual-via EBG structure is designed and applied into antenna array. By combining Fermat slot line with Archimedes spiral slot line, the size of rectangle EBG cell is reduced. Mutual coupling of 2-element antenna array is simulated. Effect of EBG structure on mutual coupling is investigated. Furthermore, a 4-element antenna array with the proposed EBG structure...
The millimeter-wave band will be one of the key components for the fifth generation (5G) wireless communication systems. A radio channel measurement was conducted at 28 GHz in a laboratory environment. Two horn antennas were used with a vector network analyzer. The transmitter antenna was fixed in one direction while the receiver antenna was rotated 360° in azimuth in the measurement. The space-alternating...
In this paper, a wideband substrate integrated waveguide (SIW) cavity backed patch antenna element is proposed for high-gain arrays at millimeter-wave bands. By compensating the inductance of the feeding metallic via with a capacitive ring slot on the ground plate, an additional resonance is introduced to the patch mode to expand the bandwidth. To suppress the backward radiation from the slot and...
Multiple-Input-Multiple-Output (MIMO) technology plays an important role in the fourth generation and future wireless communication systems to meet the exploding capacity requirements. In conventional MIMO approaches, antenna elements are placed far away from each other to eliminate the correlation and make use of the spatial multiplexing. However, this advantage offered by the MIMO comes at the price...
This paper presents the design of a 16×17 slot antenna array based on SIW (Substrate Integrated Waveguide) technique with a novel balance dual-feeding scheme. The proposed SIW antenna array consists of 16 longitudinal slot sub-arrays, and each sub-array has 17 radiation slots. Balanced dual feeding scheme is introduced to excite each sub-array from its both terminals with equal phase and amplitude...
In this paper, a full wave analysis of multiport microstrip circuits is presented, which is based on the efficient computation of spatial domain dyadic Green's functions and accurate modeling of method of moments (MoM) with perfectly matched ports. With fast and accurate extracting all the surface wave and adequate leaky wave modes, the spatial domain dyadic Green's functions of layered structures...
An integrated millimeter wave filtenna is proposed for Q-band indoor short range wireless communications (IEEE 802.11aj). Comprising of a substrate integrated waveguide (SIW) filter and a printed angled dipole with a reflector, the proposed filtenna performs a bandpass response over 43.5–47GHz and the wide beamwidth larger than 120° in main cuts. The proposed filtenna and its counterpart without the...
In this paper, an investigation on the effect of F/D ratio on gain for folded reflectarray antenna (FRA) is presented. Quantization phase errors which are the major contribution to losses of reflectarray are presented with different F/D ratios. In order to reduce the quantization phase error, a folded reflectarray antenna with high F/D ratio is preferred. A pair of FRAs with F/D of 0.5 and 1 is chosen...
In this paper, we present a UHF-band compact conformal dipole antenna. Firstly, a planar dipole antenna is designed. And several parameters of the planar dipole antenna structure are discussed in detail. Secondly, the conformal dipole antenna mounted on the cylindrical body is simulated. Finally, the small conformal dipole antenna is fabricated and measured.
The design of a microstrip reflectarray with two types of element configurations for multi-mission radars is presented. The proposed element configurations can provide an increased phasing range of single-layer unit cells that exceeds the required minimum of 360°. An air/foam layer is inserted between substrate and conducting ground to offer a slow phase slope as their varying sizes, and thus gives...
In this paper we present some channel measurement results of distributed multiple-input multiple-output (D-MIMO) systems inside a MD-82 aircraft. Channel capacity and spatial correlation are analyzed from the measured channel matrix. Capacity results of 7 different systems (six D-MIMO systems and a SISO system) are discussed. It is found that D-MIMO systems yield significant capacity gains as compared...
A novel design of dual-linearly-polarized antenna for Ku-band satellite communication system is presented in this paper. This antenna consists of a patch, a circle-ring slot, and a cross slot on the upper layer of substrate. The circle patch is aperture-coupled by two microstrip lines to generate dual orthogonal linearly-polarized waves. The effect of feed network on the reflection coefficient is...
A three-dimensional finite-difference time-domain (FDTD) method is applied to analyze the performance of a dual-polarized wideband patch antenna in this paper. The simulated results obtained by the FDTD method are compared with measured data. And effects of different design parameters, including inner and outer radiuses of annular-ring slot, cross-slot width, and feed-line length, on the antenna performance...
Generation and measure of nanosecond pulse with large amplitude are difficult problems in the field of exploration. The principle of avalanche transistor is analyised and four-stage serial connection of avalanche transistors is designed. Experimental results show that across the 50?? load the amplitude of the output pulse can reach 666V and half-width is 3.4 nanosecond. Repeat frequency of the pulse...
In this paper, the effects of distributed antenna systems on the power coverage characteristics and the Rician K factor are analyzed by using measured data. The novelty of this paper comes from applying actual measured channel to the distributed antenna systems (DAS) while most literature so far on properties of power coverage and fading in DAS considers only theoretical channels. The measurements...
The onboard wireless communication in an airplane is very attractive for it can provide data, audio and video services very conveniently. Because many radio equipments should be powered down in the airplane, the available frequency band for broadband communication is very wide. The frequency used in the airplane should be carefully allocated so that the onboard communication system does not affect...
This paper presents a radio propagation measurement system for wideband multiple-input-multiple-output (MIMO) measurements at 3.52 GHz. MIMO channel matrix of size 7times7 can be measured using fast microwave switches at the transmitter (TX) and the receiver (RX).The system is capable of measuring the direction of departure (DOD) and direction of arrival (DOA) in the vertical polarization in both...
In this paper, some recent research advances in compact ultra-wideband antenna with multiple stop bands for UWB wireless communications or shared for multiple wireless communication systems are reviewed.
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