Planar monopole folded into a compact structure for very‐low‐profile multiband mobile‐phone antenna

Abstract

A planar monopole consisting of three branch strips and folded into a rectangular‐box‐like compact structure for very‐low‐profile GSM/DCS/PCS multiband mobile‐phone antennas is presented. The three branch strips are designed to operate as quarter‐wavelength structures at 900, 1800, and 1900 MHz, respectively, and the obtained impedance bandwidths cover the required bandwidths of the GSM band (890–960 MHz), the DCS band (1710–1880 MHz), and the PCS band (1850–1990 MHz). The proposed antenna has a compact size of 6.5 mm in height, 6 mm in width, and 25 mm in length, and can be mounted on top of a mobile phone with a small distance of 3 mm to the ground plane, resulting in a very low profile of 9.5 mm (less than 3% of the wavelength at 900 MHz) from ground for the proposed antenna in practical applications. © 2002 Wiley Periodicals, Inc. Microwave Opt Technol Lett 33: 22–25, 2002; DOI 10.1002/mop.10219

Very‐low‐profile bent planar monopole antenna for GSM/DCS dual‐band mobile phone

“…In this Letter a novel dual-band monopole design with an even lower profile than that shown in [2,3] is presented. The planar monopole is first printed on a thin FR4 substrate and then bent into a three-dimensional structure having two equal and perpendicular sections.…”

“…Recently, it has been demonstrated that, by folding the planar monopole into a three-dimensional structure [2,3], reduced antenna height can be obtained, which is very attractive for mobile phone applications. The design reported in [2] showed a folded planar monopole antenna having a wide bandwidth of about 900 MHz, which covers the DCS, PCS, UMTS, and WLAN bands for mobile phone applications.…”

“…This antenna has a low profile of 13 mm (less than 8% of the wavelength of the lowest operating frequency) from the ground plane for practical applications. In [3], a very-low-profile design of a planar monopole folded into a rectangular-box-like compact structure for GSM/DCS/PCS multiband mobile phones has been shown. The total antenna height from the ground plane is only about 9.5 mm (about 2.9% of the wavelength at 900 MHz).…”

Multiband and Wideband Antennas for Mobile Communication Systems

“…The antenna can be tuned to operate either in GSM 850, 900 and 1900 bands or GSM 850, 900 and 1800 bands by providing VSWR≤2.5 within the given frequency bands. In another realized antenna (Teng & Wong, 2002), a structure consisting of three meandered lines and wrapped into a compact rectangular box is presented for GSM 900, 1800 and 1900 frequency bands. The proposed antenna covers the required bandwidths of GSM 900, 1800 and 1900 by having VSWR less than 2.5 and gain ranging from 1.4 to 3.6 dBi.…”

Planar multiband antenna for 3G/4G advanced wireless services

“…However, they often present a narrow bandwidth [13] because of the small distance between the ground plane and the radiating patch. Monopole antennas also received a great interest for an efficient integration of the radiating component in small portable devices, but additional branch structures are usually necessary to yield a multiband behavior [14,15]. Alternative techniques have been also proposed to obtain multiple resonances with a single monopole antenna.…”