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The parabolic equation method has been widely used in the contexts of radar, remote sensing, and radio frequency planning, among other fields. It is an approximate means of solving wave propagation problems, and it has high computational efficiency compared to the Helmholtz full-wave equation. In this study, we derive the finite difference format with polar coordinates. By using this formula, the...
The mobile operators often use point-to-point microwave connections for feeder links in their access networks. However, the estimation of the propagating field of electromagnetic wave which is mainly solved along the propagating-link, but is less trend to solved by point-to-point in engineering application. The main reason is that wave propagation at the applied frequencies is highly influenced by...
This paper concentrates on the propagation loss of the rooftops of buildings in urban environment by using parabolic equation. The radio communication is direct to each subscriber, the prediction of signal strength is most important in urban environments where subscriber density is high, and the buildings have a profound influence on the propagation. Because of complexity of radio propagation theoretical...
For the first time, we use the nonlocal boundary conditions in wide-angle finite difference parabolic equation model to calculate the propagation loss in complex environment. The great advantage of this method is that it has less amount of calculation without any loss of accuracy. The correctness and accuracy of this method are proved by using it to compute some propagation examples.
The capacitance matrixes of coupled micro-strip lines are studied. The influences of surrounded conductor on the capacitance matrix of transmission line are discussed and analyzed. It is found that the distributed capacitances of coupled micro-strip lines has an important impacts with surrounded conductor.
Electromagnetic band gap (EBG) is widely used to suppress the transportation of simultaneous switching noise (SSN) in circuit. But the periodic High impedance planes of EBG destroy the return path of signal line. That phenomenon leads serious problem of signal integrity, which makes the research of EBG more important. In this paper, a new structure of EBG with multi-via and double-layer structure...
The loop types such as the three- and four-legged loaded unit cells, the circular loops, and the square loops and the hexagonal loops are widely used to design the frequency selective surface (FSS) for a number of applications. Correlation analysis and evaluation of them are investigated in previous works. In this work, we try to use another loop, namely triangular loop, for designing the FSS. A multi...
A reduced computation method is proposed based on paraxial approximation of two-dimensional wave equation. This method is more easily to implement large scale numeric computation about radiowave propagation problems comparison with wave equation. The computational accuracy of this method is higher than parabolic equation (PE). In other words, the discrete size of numeric computation can be larger...
In this paper, an improved zeroth-order resonator based on composite right/left-handed transmission lines is presented. Using the proposed zeroth-order resonator a novel RF microwave oscillator is designed. Because of the using of proposed zeroth-order resonator the blocking interdigital capacitor in oscillator circuit is removed, which can simplify the design process and miniaturize the circuit size...
The research of broadband absorbing materials is of great importance in engineering application. In this paper, a broadband structural absorbing material with multilayer is studied. Different proportions of graphite and iron powders added into the cement materials, which forms the absorbing material with a multilayer sandwich structure. Firstly, in order to measure this multilayer structural absorbing...
A dual band and compact multi input multi output (MIMO) antenna for WLAN has been present in this letter. The proposed antenna operates over a wide frequency range of 1.93–2.79 GHz and 4.79–6.19 GHz suitable for long-term evolution (LTE) and wireless local area network (WLAN). The two elements antenna with a compact size of 39×40×1.5 mm3 which is designed on a FR4 substrate with a dielectric constant...
AMC (Artificial Magnetic Conductors) is an important part in the research about artificial electromagnetic materials. Currently, the main two trends in AMC is miniaturization and low-frequency design, especially the latter, which can help applying AMC into wireless communication antennas. This paper discusses some kinds of low-frequency AMC structure, with interleaved gap and lumped elements as key...
An ultra-thin and broadband absorber which consists of periodic rings with gaps is proposed in this paper. The periodic rings are printed on the middle metallic layers in a four-layer substrate of total thickness is only 3.4mm. Simulation results, which are gotten by using FEM, show that the absorption is higher than 90% cover the frequencies range from 8.4GHz to 23.6GHz. The measurement results of...
A dual band multiple-input-multiple-output (MIMO) antenna with high isolation for LTE and WLAN has been presented in this paper. To improve the isolation of each element, the two elements are placed 180° apart on FR4 substrate (78×40 mm2). The simulated results show that the proposed MIMO antenna operates at the following frequency bands: 2.20– 3.15 GHz and 5.24–5.83 GHz while |S11|<10 dB, with...
This paper presents a new metamaterial-based waveguide technology referred to as packaging gap waveguide, which is used to improve the performance of zeroth-order resonator (ZOR). In this approach, a lid of spiral nails used for perfect magnetic conductor (PMC) together with the ground plane of the substrate created a gap to suppress the power leakage problem of ZOR. Compared with the previous pin...
In this article, an indoor radiowave propagation loss measurement environment which worked at 9.375Ghz was built and a series of experiments about propagation loss of different situated Knife-Edge were implemented. The Knife-Edge position changes caused by horizontal length change and angle change were experimental studied respectively. The influence of Knife-Edge horizontal length and angle changes...
A high gain circular polarized radial line slot antenna (CP-RLSA) is reported in the design with Mat lab and HFSS interface technology to achieve the slot array model modified adjusted automation. In this paper, we find that proper adjustment of the frequency offset can get a higher gain and a lower return loss. A new material with the relative dielectric permittivity of 1.06 can help to reach the...
At low frequencies, the solution of Maxwell's equations breaks down. To overcome this problem, in this paper, a new method is proposed, which is using multi scale analysis method. A synthesis is made of the input impedance of power lines. The results are compared with the analytic solutions, and they are anastomosed. It proves that this method can solve more issues at low frequency.
This paper introduced a kind of High Impendence Frequency Selective Surface with double dielectric slaps. The performance of this structure is great and absorbing characteristic of S11 was verified from 7 to 16.5GHz under −10dB. Its thickness is only 3.9mm. Then, we proposed a new equivalent circuit structure and analyzed the absorbing material with this Equivalent Circuit Method(ECM). The analyzing...
MIMO system is a promising technology for promoting the performance of communication. In order to simulate the multipath channel in real communication, a suitable measurement environment which is not only reliable but also repeatable is very important. The reverberation chamber is a kind of common electromagnetic test environment, and it has many outstanding advantages in MIMO system test. So in this...
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