Ping Jack Soh

... b is the width across the conducting part of the coil (in cm) and N is the ... REFERENCES [1] Nak-Gwon Choi, Hyuek-Jae Lee, Sang-Hoon Leen and Seong-jeen Kim, “Design of a ... R. Dontaraju, Shenchin Tung Ralph Sparng, Josh Fazekas, James T. Cain and Marlin H. Mickle,” An ...

Meander line antenna (MLA) have been designed to operate at 2.4-GHz for WLAN application. Two different designs of meander line antenna are investigated, using conductor line and parasitic. Microwave Office software and CST is used for simulation designed process. The antenna is fabricated on a double-sided FR-4 printed circuit board using an etching technique. Then the design has been tested with the Advantest Network Analyzer. The comparison between simulation and measurement results for the return loss and radiation patterns were presented

ABSTRACT A wearable dual-band magneto-electric dipole antenna is proposed. Two U-shaped slots are introduced on a dipole and the resulting electric and magnetic resonances are combined with the aim to produce a dual band with wideband characteristics. The antenna is fabricated fully using textiles, except for the feeding connector. Simulations and measurements confirm the wide bandwidth and a low backwards radiation in both the lower and the upper band. The antenna is robust and not very sensitive to bending when worn by the user. The specific absorption rate is studied numerically and proven to be well below the European limit of 2 W/kg.

ABSTRACT This paper presents a detailed and systematic investigation of the reproducibility of specific absorption rate (SAR) measurements using textile antennas and their simulation accuracy. The ability to accurately predict the SAR is very important for practical textile antenna designers since certified SAR measurements are costly. To that goal, the SAR values of a range of textile antennas operating in various bands of the IEEE 802.15.6 and 802.11 standards are evaluated. The selected textile antenna topologies for the evaluation differ in terms of the bandwidth behavior (broadband, dual band, and ultrawideband). They are chosen to be distinct, have been fabricated using an array of conductive textiles, and are benchmarked against similar structures made from a flexible conductor. SAR values are evaluated at three different frequencies, i.e., 2.45, 5.2, and 5.8 GHz, respectively, using a commercial electromagnetic solver and a certified experimental setup. Factors affecting the SAR behavior are presented and discussed. Results indicate that antennas without a rear ground plane are producing almost three times the SAR of textile antennas that feature a full ground plane. The results of this paper point out that the repeatability of the measurements is about 10Q and that the agreement between simulations and measurements is on the order of about 17 %.

ABSTRACT The efficiency of a method of moments procedure for microstrip antennas is strongly dependent on the convergence of the inverse Fourier transformation (IFT) from the spectral to the spatial domain. This is especially true when considering cylindrical microstrip antennas (CMAs). In the cylindrical case, the calculation of the two-dimensional Green's functions stays inherently time-consuming. In the planar case, Green's function can be reduced to a one-dimensional function. The problem, however, becomes a real bottle-neck when probe feeding of a CMA is considered, as the traditional IFT used to calculate the excitation in the spatial domain results in a huge IFT time. In this paper, this problem is explicitly treated. The asymptotical behavior of the probe-related spectral Green's functions (GFs) is rigorously derived, subtracted, and the corresponding reaction integrals are inverse Fourier transformed without the occurrence of any cylindrical functions. This results in a much improved calculation efficiency for this type of feeding, evident for both thin and thick substrates. Numerical results for CMAs with complex-shaped patches are presented, applicable to both smaller and larger bandwidths. Several structures are fabricated and measurements are in good agreement with simulations.

ABSTRACT This paper describes the design and simulation of Sierpinski Carpet Fractal Planar Inverted F Antenna (PIFA) for WLAN and HiperLAN applications. Simulation of antenna is carried out using CST software; on a FR4 board with a substrate thickness of 1.6 mm and relative permittivity of 4.7. The antenna achieved satisfactory 10-dB impedance bandwidths, between the frequencies of 2341-2812 MHz and 5360-6154 MHz, which applies to Bluetooth, WLAN and HiperLAN applications. Performance of the proposed antenna is discussed in terms of reflection coefficient (S11), radiation patterns, and gain. Analysis of the result indicated that the number of resonances increases linearly with the number of iteration. On the other hand, bandwidth produced is also largest at the highest resonance point. In the final design, the proposed first fractal iteration produced the desirable trade-off between bandwidth adequacy and resonating at the desired frequencies.