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A novel hybrid patch/stacked hollow rectangular dielectric resonator antenna (DRA) operating in dual modes is presented. The linearly polarized (LP) monopole like radiation patterns can be obtained with the stacked hollow rectangular DRA fed by four symmetric microstrip lines. A truncated microstrip patch is placed on top of the stacked hollow DRA for broadside circularly polarized (CP) operation...
In this paper, a novel electro-magnetic complementary antenna composed of bow-tie shaped meander slot antenna and dipole is proposed. Compared with the original slot antenna without dipole, the proposed antenna exhibits a great improvement on impedance bandwidth and front-to-back ratio (FBR). Measured results show that the impedance bandwidth increases from 2.7% of the original slot antenna to 26...
Planar periodic metallic arrays behave as artificial magnetic conductor (AMC) surfaces when placed on a grounded dielectric substrate and they introduce a zero degrees reflection phase shift to incident waves. A novel gradually concentric ring arrangement AMC (GCRA-AMC) applied to the broadband RCS reduction is presented. The simulated results show that the radiation performance of antennas is preserved...
This paper presents an easier method for the prediction of the field strength inside multiple cavities with a relatively high volume by using the analysis method based on statistical approaches. For the accurate analysis, in general, FDTD, FEM, MOM requiring much time-consumption in employing and solving a complete Maxwell equations have been provided by many commercial software companies. Compared...
A compact microstrip lowpass filter with a wide stopband is proposed in this paper. To achieve wide stopband suppression and compact size, nonuniform radial stubs are adopted. The proposed lowpass filter is composed of four nonuniform radial stubs, four transmission lines, and two standard ports. A filter with the 3-dB cutoff frequency of 900 MHz is fabricated and measured. The fabricated lowpass...
This paper presents an experimental result on the measurement of the lobular radiation pattern of directional antennas (Yagi) obtained by applying a SDR (Software Defined Radio) system for the homologation and verification of the antenna performance. The measurement depends on the energy absorbed by the antenna when it is used to received a RF signal of short wave.
The synthesis and electromagnetic wave absorbing characterization of La1−yBayMnO3 (y = 0−1, 0) magnetic material through a mechanical milling process have been performed. The La1−yBayMnO3 (y = 0−1, 0) magnetic material was made from La2O3, BaCO3, dan MnCO3 materials. The mix was milled for 10 hours and then sintered at 1000 oC for 10 hours. The results of the the hysteresis curve indicated that that...
Firstly, a compact current feedback amplifier-based negative impedance converter (CFA-based NIC) is designed and its equivalent circuit is proposed. Secondly, to obtain a stable negative inductor, a stabilization network is developed and combined with the CFA-based NIC. Meanwhile, the stability of the combined circuit is analyzed in the time domain by the method of Routh-Hurwitz criterion (R-H criterion)...
We analyze the error caused by having a thin layer of dielectric material surrounding a cylindrical rock sample in a coaxial-circular measurement cell. We develop a full-wave model that can predict the fields inside the cell and the reflection coefficient from the coaxial-circular junction. Galerkin's approach has been used to determine the electromagnetic fields in different parts of the cell by...
Due to the limitation of Cell-specific Reference Signals (CRS), the channel estimation for LTE downlink system is a challenging topic, especially for vehicular users at high speed suffering from severe fading. In this paper, an improved channel estimation method with downlink channel signaling aided detection is proposed for LTE downlink system. The considered specific signaling symbols include the...
This paper presents a rectangular dielectric resonator antenna (RDRA) for ZigBee applications. In the antenna design, the resonator is fed by a coplanar waveguide and the resonator is placed above a RT 5880 substrate. The air space between the resonator and the substrate is optimized to adjust the antenna operation frequency and bandwidth. In addition, the measurement is carried out in the anechoic...
This paper introduces the modulation and demodulation module for tri-networks integration. With the zero-IF structure and a digital interface, the system covers GSM900, GSM1800, 3G, WLAN and 4G-LTE frequency bands, offering a miniaturized and flexible realization. The EVM measurement results are below 1% for modulation link and below 1.5% for whole link with different bandwidth signals. The ACLR results...
An ultra-wide band monopulse antenna array, which consists of log-periodic zigzagged sharp antenna, is designed and simulated by HFSS. The log-periodic antenna is zigzagged to reduce the volume. By adjusting the phase of the feed current along the array the sum pattern and difference pattern can be obtained. The simulated results are presented, and ultra wide band monopulse properties have been obtained.
A simple experiment to verify the applicability of self-oscillating active integrated antennas (AIAs) to wireless power transmission system is discussed in this paper. The verification consists of a dual-ring AIA and a half-wave rectifier along with a receiving patch. The spacing between the antennas satisfies the far field condition. According to experiment results, comparable DC voltage to that...
In this paper, a time-domain augmented electric field integral equation (TD-AEFIE) with improved current continuity equation is proposed to avoid the derivative of the charge density, which is also the unknown together with the current density. The main purpose of this improvement is to overcome the discontinue of the derivative of temporal basis function existed in the original current continuity...
In this paper, a differential rectenna with matching shorted stubs is proposed and experimentally evaluated. The shorted stub improves the rectenna's performance by achieving the impedance matching between an antenna and a diode. A 3-dB improvement of RF-to-DC conversion was obtained under the low RF power density of 0.006 W/m2.
A compact fourth-order spatial accuracy unconditionally stable 6-stage split-step finite-difference time-domain (SS6-FDTD) method is developed, that achieves higher computation efficiency than the previous original fourth-order SS6-FDTD by reducing the band-width of the system involved. Dispersion analysis of the proposed method shows that due to the fourth order accuracy in space, compact fourth-order...
Planar antenna has broad application prospects in microwave backhaul system, many studies have been made on this topic. To explore the potential of different kinds of low cost planar antenna technologies, three antennas based on different low cost fabrication process have been studied, their structure and performance are presented in this paper.
In this paper, a millimeter-wave sinusoidally-modulated susceptance leaky-wave antenna (SMSLWA) based on dielectric filled metal groove waveguide is presented. The design procedure for SMSLWA with the desired radiation direction is discussed in detail. The proposed antenna radiates at 10o from broadside at 60 GHz. The simulated results show that the main beam scans from −21.2° to 40.6° from 45 to...
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