Abstract-A multiband internal antenna is introduced. The antenna consists of a driven meander-line element and two parasitic elements. The design is particularly unique since it supports the third generation mobile phone handsets where multiband operation is greatly desired. The proposed antenna operates effectively in the AMPS 800 (824-894 MHz), GSM 900 (880-960 MHz), and GSM 1900 (1850-1990 MHz) bands within 2.5:1 (voltage standing wave ratio (VSWR). Detail design criteria with respect to geometrical parameter variation are given. Experimental data (VSWR and pattern) obtained from a laboratory prototype are also presented.

A CPW-fed inductively coupled bow-tie slot antenna is introduced. The bandwidth reduction for an inductively coupled straight-dipole slot is overcome by utilizing a bow-tie slot. Antennas operating at 2.45 and 5.5 GHz are proposed that have 10 dB return loss bandwidths of 12% and 17%, respectively. Prototype antenna elements and a two-element series-fed array were fabricated and tested to validate performance.

suitable to describe the singular behavior of the spatial GF. In its turn in the improved version the analytical part derived in the explicit form provides with this behavior. It can be easily derived from Fig. 2 that the numerical part (dash-point line) of the improved GF gives a considerably smaller contribution in the vicinity of the origin than the analytical one. This numerical part can be calculated with guaranteed accuracy. The real part of the plotted GF is not singular at the origin and its values calculated with and without the analytical extraction coincide. V. CONCLUSIONIn this paper, a rigorous way to extract the singularity of the spatial GFs for a sheet electric current over a dielectric coated cylinder is proposed. The spatial GFs are required to analyze cylindrical microstrip antennas. Up to now the direct rigorous numerical calculation of the spatial GFs using the IFT in practice was not possible because of the hidden singularity. The singular part of the spatial GFs is derived in an analytical form. The remaining part of the spatial GFs is calculated numerically with guaranteed accuracy. The proposed spatial GFs can be effectively used in the moment method formulation for cylindrical microstrip antennas. Thus, our approach allows extending the concept of the mixed-potential formulation, which proved its efficiency for planar structures, to cylindrical structures. REFERENCES

Abstract-A dual-band R-shaped planar inverted-F antenna is proposed for vehicular application. Utilization of this unique geometry dual-frequency operation is achieved with a single feed. The proposed antenna operates in the 225-and 450-MHz bands. Input impedance and return loss data as function of various antenna parameters are presented, which show that parameters can be adjusted in order to obtain optimum tuning. Radiation pattern data for the antenna mounted on the roof of two types of vehicles are given. The pattern in the low-frequency band is essentially omnidirectional while that in the high-frequency band is directional and normal to the antenna surface. With proper scaling, this antenna may be suitable for dual-band GSM 900/1800-MHz phone applications.

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