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In this article, a novel compact microstrip-fed slot antenna with dual band-notched characteristic is proposed. The proposed antenna consists of a circular patch and a multiple ground plane. By inserting two U-shaped slots to the circular patch and adjusting the dimensions of the slots, the antenna can reach a frequency band-width from 2.9 to 15.6 GHz for voltage standing wave ratio (VSWR) <; 2...
The design simulation and measurement of a highly miniaturized compound spiral antenna is presented. The compound spiral antenna is designed by combining a typical equiangular spiral antenna with new terminals. Favorable wideband properties are shown in the simulated and measured results. The measured return loss is less than -10 dB in the frequency range from 1.6 to 10 GHz and the axial ratio is...
A novel printed side shaped elliptical monopole with ultra-wide bandwidth is presented in this paper. The antenna is simulated with CST software and fabricated on a Rogers 5880 dielectric substrate. The measured impedance bandwidth with VSWR<;2 is from 0.8GHz to 6.3GHz. The short axis of the elliptical radiator is reduced for compact designation, and two notches at the sides of the ellipse are...
A novel planar tree-shaped fractal dipole patch antenna using arc branch is proposed. The advances in development of tree-shaped fractal antenna are outlined in the paper; a novel tree-shaped fractal antenna is designed, which is fed by a simpler balun. The resonant frequency of the two iterative fractal antenna is 37.5% lower than the zero iterative fractal one. The two iterative fractal antenna...
Time Based (TB) localization by terrestrial cellular communications mobile radio as a complementation to Global Navigation Satellite Systems (GNSSs) has gained plenty of interests. Apart from multipath considered in standard communication channel models, the Non Line-of-Sight (NLoS) error due to an undetectable Line-of-Sight (LoS) path, defined as the additional propagation distance between the first...
An advanced acquisition system is established to implement on-site measurements so as to characterize the electromagnetic interference (EMI). The time-frequency analysis methodologies, including instantaneous frequency analysis, short-time Fourier transform, Wigner-Ville distribution and so on, are introduced to extract and present more detailed EMI information to characterize the electromagnetic...
In order to compare satellite-to-indoor wave propagation channel characteristics between L-band and C-band for satellite navigation applications the German Aerospace Center (DLR) conducted a measurement campaign in June 2008. The measurements were performed at 1.51 GHz for L-band and at 5.2 GHz for C-band with a broadband signal of 100 MHz bandwidth. A mobile crane was used as transmitter platform...
In electromechanical coupled analysis of large reflect antennas, the mesh for structure analysis does not match with the mesh for electromagnetism analysis. For this problem, the geometrical optics method is used for electromechanical coupled modelling. A transformation matrix for different meshes has been deducted based on the structure mesh. Use this transformation matrix and improved Gaussian integral...
On the inefficient panel adjustment of large reflector antenna, a method for determination of panel adjustment magnitude according to far field pattern is presented. Using the method of Physical Optics (PO), the relationship between the far field value and the node displacement is derived. Then the panel adjustment vector is related to far field pattern with linear equations. Singular value decomposition...
Time Based (TB) localization in terrestrial cellular mobile radio as a complementation to Global Navigation Satellite Systems (GNSSs) has gained plenty of focuses. Due to absence of the Line-of Sight (LOS), Time of Arrival (ToA) of the First Path (FP) and/or corresponding Time Difference of Arrival (TDoA) are drifted from their true values. However, there are few analyses in terms of geolocations...
The time based localization utilizing cellular communication networks has been investigated as a complementation to Global Navigation Satellite Systems (GNSS) for critical scenarios, like indoor or urban canyon areas. By suitable Hybrid Data Fusion (HDF) algorithms which combine the information from GNSS and terrestrial cellular networks, the estimated position accuracy can be improved. However, the...
Due to the non-flat amplitude-frequency characteristics of the antennas used in EMC measurement, it is desired to establish the equivalent transfer functions of the antennas so as to make digital correction to the measured data, from which the actual electromagnetic interference can be traced back. This paper describes a new algorithm for the fitting of measured frequency domain responses with transfer...
The weather factors with on-site EMC measurement may differ a lot from the standard calibration condition, so it is necessary to analyze the impact of weather factors, such as temperature, humidity and atmosphere pressure, on the measurement accuracy of the antennas. Based on experimental study, digital signal processing, improved vector fitting methods and artificial neural networks (ANN), a comprehensive...
Due to frequent switching of the thyristors in a static Var compensator installed within a power substation, large amount of broadband electromagnetic emissions are being generated, which results in electromagnetic contamination to both the power grids and the victim electronic devices positioned nearby. Based on optical fiber, circuit and field transducers, an advanced acquisition system is established...
To investigate the satellite-to-indoor wave propagation channel for navigation applications the German Aerospace Center conducted broadband channel sounder measurements using a mobile crane as transmitter platform with the receiver being placed indoors. Using this setup, measurements were performed for L-band at 1.51 GHz and C-band at 5.2 GHz with a broadband signal of 100 MHz bandwidth. Results are...
This paper presents a novel passive measurement approach to accurately evaluate the performance of outdoor multi- hop 802.11 networks from the wireless side directly. Our approach employs five processing steps to evaluate per-hop system performances. Firstly, reference packets are identified from multiple independent packet traces. Secondly, multiple packet traces in one channel are merged together...
In recent years, ultra-high-frequency (UHF) radio frequency identification (RFID) systems have drawn more and more attentions in a wide variety of applications such as retail item management, access control system, electronic toll collection, and etc. By incorporating with a commercial RFID reader, it has been noted that the phased array antenna can be implemented in a RFID system to either control...
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