Global Positioning System Patch Antenna Research Articles

Development of performance‐improved global positioning system (GPS) patch antenna based on sol‐gel‐synthesized dual‐phase (Bi4Ti3O12)X – (CaCu3Ti4O12)1–X composites

As a first attempt, a series of composite materials of general formula (Bi4Ti3O12)X – (CaCu3Ti4O12)1–X (BTOX – CCTO1–X) (X = 0–1.0) is synthesized by a sol‐gel combustion method. The phase changes, including their formation and evolution during the gradual substitution of BTO into CCTO are analyzed from the X‐ray diffraction pattern. The Jana2006 refinement plotting method proves that formation of an ideal dual‐phase composite system with separate orthorhombic and cubic phases occurs. A surface morphological study revealed that the BTOX – CCTO1–X composites are composed of small CCTO grains embedded in large BTO grains and both coexisted with a bimodal distribution. The possible vibrational modes of interactions between the constituent phases are determined from Raman spectra. Our inexpensive, combustion method for BTO0.2 – CCTO0.8 gives a high dielectric constant (ε′ = 3232) at 100 Hz at room temperature. The nature behind these data is revealed that the BTO‐CCTO composite can be applicable for the fabrication of miniaturized global positioning system (GPS) patch antennas. The fabricated GPS patch antenna shows optimum results of small size (2.37 mm × 1.18 mm), return loss (‐14.419) and wide bandwidth (350 MHz) to be operated at 1.57 GHz.

Small global positioning system patch antennas with self-biased NiCo-ferrite films

Magneto-dielectric substrates with thin ferrite films show great potential in realizing small antennas with improved omni-directional performance than those realized on dielectric substrates.This article introduces self-biased NiCo-ferrite films as a practical means to tune a patch antenna by loading a commercially available dielectric substrate. Novel antenna designs with self-biased ferrite films were investigated, and these magnetic antennas have improved the axial ratio from 1.45 to 1.0 dB with respect to the central frequency ranging from 1.575 to 1.561 GHz in the simulations. Experimental global positioning system patch antennas with/without ferrite films were fabricated and tested. The measured results demonstrate that antennas with ferrite films can miniaturize the geometrical dimension by shifting down the resonance. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:1162–1165, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25909

High Dielectric Constant and Low‐Loss Microwave Dielectric Ceramics Using (Zn0.95M2+0.05)Ta2O6(M2+=Mn, Mg, and Ni) Solid Solutions

High dielectric constant and low‐loss ceramics in the (Zn0.95M2+0.05)Ta2O6(M2+=Mn, Mg, and Ni) ceramic family have been prepared by the conventional mixed‐oxide route and their crystal structures and microwave dielectric properties have been investigated. The forming of (Zn0.95M2+0.05)Ta2O6(M2+=Mn, Mg, and Ni) solid solutions was confirmed by the X‐ray diffraction patterns, high‐resolution transmission electron microscopic lattice images, the energy‐dispersive X‐ray analysis, and the measured lattice parameters. The dielectric properties exhibited a significant dependence on the sintering condition and crystal structure of the ceramics. A fine combination of microwave dielectric properties can be achieved in the (Zn0.95Mn0.05)Ta2O6ceramics sintered at 1325°C for 2 h with a dielectric constant of ∼38.56, aQ×fvalue of ∼92 700 GHz (wheref=7.64 GHz, is the resonant frequency), and a temperature coefficient of resonant frequency (τf) of ∼8.9 ppm/°C. It is proposed as a suitable candidate material for small‐sized global positioning system patch antennas.

Design of a Shape-Constrained Dual-Band Polygonal Monopole for Car Roof Mounting

This paper describes the design of a new compact dual-band roof antenna (which is capable of operating in both U.S. and European mobile telephone bands) for automotive applications. The flipper shape of the antenna and its dimensional constrains are chosen according to prevailing automotive market trends. The chosen basic geometry of the radiating element is a planar printed monopole structured as a vertical fan with two narrow strips folding toward the ground plane and etched on a low-cost, medium-permittivity thin substrate. The geometrical variations of the basic radiating structure are introduced afterward to constrain the antenna shape under the assigned profile and to allow easy integration of a small Global Positioning System patch antenna without affecting radiation and bandwidth performances. The integration of a matching network directly over the etched monopole trace allows a good input matching over the lower and upper operative bands to be obtained, slightly affecting the radiation efficiency of the whole antenna.