-
[show abstract]
[hide abstract]
ABSTRACT: The main goal for the CVIS (Cooperative Vehicle-Infrastructure System) project is to create a wireless network between vehicle and roadside infrastructure. CVTS includes implementation of technology components, to develop a multichannel terminal. This terminal will be installed in a vehicle, and in this paper we report on the development of the Rooftop Antenna Unit. The antenna unit contains 5 individual antennas, including two WLAN antennas. The WLAN antenna is a broadband double-fed printed monopole antenna designed and optimized within the CVIS project. It covers the frequency band 2.0-6.7 GHz, a bandwidth of 128%. The Rooftop Antenna Unit will be used for the CVIS field trials, taking place at six different test sites throughout Europe.
Wireless Technologies, 2007 European Conference on; 11/2007
-
[show abstract]
[hide abstract]
ABSTRACT: A double-fed printed monopole antenna having a wideband characteristic is presented. The monopole is rectangular in shape and is fed by a 50 ohms two-branch microstrip line. The antenna is designed and prototyped on a FR4 substrate. Both the simulated and measured results for impedance bandwidth are presented together with measured radiation patterns. The impedance bandwidth of the antenna is 2.2 GHz to 7.5 GHz covering all WLAN bands and frequencies in between. The antenna possesses approximately.omni-directional radiation properties throughout this bandwidth. It is easily fabricated using low-cost printed circuit technology. In addition this antenna is mechanically stable and readily Integratable with various mobile and portable devices.
Antennas, 2007. INICA '07. 2nd International ITG Conference on; 04/2007
-
J.K.H. Gamage
[show abstract]
[hide abstract]
ABSTRACT: An efficient method for analyzing large planar scatterers in a
homogeneous medium is implemented. A space domain method of moment (MoM)
approach has been employed since the corresponding spatial Green's
functions are simple and available in closed form. In order to minimize
the singular behavior attached to the Green's functions, the electric
field is expressed in terms of vector and scalar potentials, thus
leading to a mixed potential integral equation (MPIE) system. The mutual
impedance coefficients to be determined are four-fold integrals and
contribute to much of the computation cost of the matrix filling. They
can be reduced to two-fold by transferring the del operator (∇)
from the Green's functions kernel to the testing functions and
substituting analytical expressions for the resulting cross correlations
between the expansion and testing functions. The remaining two-fold
integrals are evaluated numerically using a quadrature method which
minimizes the number of functional evaluations. The singular integrals
are evaluated efficiently by transforming them to polar coordinates. The
selection of a uniform grid further introduces some symmetries. These
symmetries are exploited to reduce the computational complexity to less
than one fifth of the original. Hence, we can save the computer memory
usage by mapping the calculated coefficients in an innovative way rather
than storing them explicitly. The resulting equation system is solved by
applying an iterative matrix solving algorithm called the conjugate
gradient (CG). The matrix multiplications encountered in the
implementation of CG algorithm are efficiently performed using the fast
Fourier transform (FFT) thus reducing the matrix solution time
significantly. The present approach is applied for analyzing large
planar scatterers and the results are presented
Antennas and Propagation, 2001. Eleventh International Conference on (IEE Conf. Publ. No. 480); 02/2001
