Dual‐band ferrite chip antenna for global positioning system and bluetooth applications

Abstract

Figure 6 shows the measured radiation patterns including the co-polarization and cross-polarization in the H-plane (x-z plane) and E-plane (y-z plane). It can be seen that the radiation patterns in x-z plane are nearly omnidirectional for the three frequencies. CONCLUSIONSIn this article, a compact planar triangular monopole antenna is proposed that exhibits multioctave bandwidth performance and easily satisfies the requirements for UWB applications. The measured results show that the impedance bandwidth of the proposed antenna is significantly improved with the inclusion of square notches on the radiating patch, a narrow rectangular parasitic element located above the patch, and using a truncated ground-plane containing side slits. The measured results show good radiation patterns within the UWB frequency range. of the composite were in the range of 1.92-2.12 and 7.33-7.45, respectively, from 1.575 to 2.45 GHz. Magnetic and dielectric loss tan d of Co 2 Z-glass composite was <3.5% in the 1.5-3.0 GHz range. The 3D average gain and bandwidth of the 40h-shake-milled and sintered Co 2 Zglass composite antenna were À1.27 dB and 355 MHz at 1.575 GHz, À4.08 dB and 270 MHz at 2.45 GHz, respectively. Simulated Sparameter spectrum is in good agreement with experimental results. Key words: dual band antenna; ferrite chip antenna; GPS; bluetooth; hexaferrite INTRODUCTIONDual-band chip antenna was developed to work on both Global Positioning System (GPS; 1.575 GHz) and Bluetooth (BT; 2.45 GHz) for wireless handset. To miniaturize the dual band antenna to 100 mm 3 of the antenna volume, a radiator was embedded between two dielectric slabs. However, this embedded dielectric antenna shows low gain (GPS À2.6 dB, BT À2.4 dB) and narrow bandwidth (GPS 90 MHz, BT 130 MHz) [1]. However, the use of ferrite allows for achieving higher gain and broader bandwidth than the embedded dielectric antenna. Nonembedded radiator structure of ferrite antenna leads to better performance, while having the same volume of the embedded dielectric antenna. This is because the ferrite possesses both permeability and permittivity.Recently, the low loss Ba 3 Co 2 Fe 24 O 41 (Co 2 Z) has been developed [2,3] to miniaturize the VHF ferrite antenna [4]. To meet the GPS-BT dual-band frequencies, both magnetic and dielectric losses of the Co 2 Z are needed to be low enough up to 2.45 GHz of the BT frequency. Therefore, the Co 2 Z-glass composite was developed for use in the dual-band antenna. In this article, the dynamic properties of the developed low loss Co 2 Zglass composite and performance of the dual-band Co 2 Z-glass composite chip antenna are reported. EXPERIMENTALThe Co 2 Z-glass composite was used to fabricate the antenna substrate. The Co 2 Z powder was prepared by the one-step mixing and calcination process [3]. Borosilicate glass powder was mixed with 40h-shake-milled Co 2 Z powder. The ring shaped green bodies of the mixed powder were prepared by pressing with a steel mold and followed by sintering at 950 C for 1 h for dynamic magnetic characte...

Magnetocrystalline Properties of Sr_1.4Ba_1.6Co₂Fe₂₄O₄₁

“…A particular characteristic of Co2Z is its low coercivity and high Curie temperature (410 °C) [8]. Furthermore, its high magnetic permeability of 300 MHz to 3 GHz [9] and high frequency magnetic resonance of up to 5 GHz [7] makes Co2Z particularly attractive for broadband Bluetooth [11] and Dual-Band global positioning chip antennas [11], in the form of composite and multi-layer chip inductors (MLCI) [12].…”