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Abstract-A compact quad-band hybrid antenna for Compass/WiMAX/WLAN applications is proposed. The hybrid antenna is designed based on the method of combining a composite right/lefthanded transmission line (CRLH-TL) unit cell with a meandered monopole and wide multi-band characteristics are achieved by merging some of resonance frequencies of the CRLH-TL unit cell and meandered monopole together. Coplanar waveguide (CPW) is used as a parallel excitation for both the CRLH-TL unit cell and meandered monopole. A prototype of the proposed hybrid antenna has been constructed and experimentally studied. The measured results show that four distinct operating bandwidths with 10 dB return loss are about 30 MHz (1.25-1.28 GHz), 290 MHz (2.44-2.73 GHz), 650 MHz (3.17-3.82 GHz) and 1130 MHz (5.03-6.16 GHz), covering the Compass B3, 2.5/3.5/5.5 GHz WiMAX and 5.2/5.8 GHz WLAN bands. Furthermore, the antenna has a single-layer planar structure with a small volume of only 31 × 21 × 2 mm 3 . Acceptable radiation patterns and peak realized gains are obtained over the operating bands.

A compact coplanar waveguide (CPW)-fed printed monopole antenna comprising of two symmetrical C-shaped radiating elements, a parasitic E-shaped strip, and a truncated CPW ground for WLAN/WiMAX applications is proposed. By embedding a parasitic E-shaped strip inside the two symmetrical C-shaped radiating elements, four resonant frequencies and three operating bands are obtained. By etching two quarter-circles in the CPW ground, impedance matching condition of the third operating band is significantly improved. A prototype of the proposed antenna has been constructed and experimentally studied. The measured results show that three distinct operating bandwidths with 10 dB return loss are about 500 MHz (2.33-2.83 GHz), 700 MHz (3.27-3.97 GHz) and 2.37 GHz (4.3-6.67 GHz), covering all the 2.4/5.2/5.8 GHz WLAN and 2.5/3.5/5.5 GHz WiMAX bands. Furthermore, the antenna has a simple planar structure and a small volume of only 31 × 21 × 1.6 mm 3. Good radiation characteristics and acceptance peak realized gains are obtained over the operating bands.

In this paper, we present a compact stacked wideband Modified-PIFA with ferrite loaded, working at the upper part of the VHF and the lower part of the UHF band. The antenna consists of two layers stacked thin copper with slots as the radiation plates. a common shorting plates and a L-shaped ground with slots. In order to reduce the size of the antenna, ferrite is used as the substrate and various shapes of slots are used to improve the bandwidth and impedance matching of the proposed antenna. By carefully adjusting and optimizing the size of the patches and slots, the two layers radiation patches generate three resonance frequencies close to each other, expanding the bandwidth significantly. The overall optimized dimension of the compact stacked wideband Modified PIFA is 36mmx36mmx6mm and its ground plane size is 61mmx4SmmxSmm. The measurement results show it can work perfectly between 256MHz and 37SMHz, and the relative bandwidth is about 3S.49%.It has the potential to be used in the wireless audio system.