Tri‐band rectangle‐loaded monopole antenna with inverted‐L slot for WLAN/WiMAX applications

Abstract

A novel coplanar waveguide-fed tri-band monopole antenna with a compact radiator (10 × 23 mm 2 ) for WLAN/WiMAX applications is presented. By etching properly an inverted-L slot on the straight strip loaded with a rectangular tuning patch and further adjusting the dimensions and positions of these structures, three distinct wide bands can be achieved. The measured and simulated results show that the proposed antenna has 10 dB impedance bandwidth of 470 MHz (2.38-2.85 GHz), 360 MHz (3.36-3.72 GHz) and 890 MHz (4.98-5.87 GHz) to cover all the 2.4/5.2/5.8 GHz WLAN bands and 2.5/3.5/5.5 GHz WiMAX bands. Also, the proposed antenna produces good dipole-like radiation pattern over the covering bands.Introduction: Currently, the wireless local area network (WLAN) and the worldwide interoperability for microwave access (WiMAX) have been widely used in mobile devices. To support the WLAN and WiMAX applications in the 2.4 (2.4-2.484 GHz)/5.2 (5.15-5.35 GHz)/5.8 (5.725-5.825 GHz) and 2.5 (2.5-2.69 GHz)/3.5 (3.4-3.69 GHz)/5.5 (5.25-5.85 GHz) bands, respectively, many multiband antennas have been reported. In [1], the antenna with a dual-layer metallic structure is presented for WLAN/WiMAX applications. In [2], three types of structures are used to achieve triple band to cover the WLAN/WiMAX bands. However, these proposed antennas are complicated in structure and the resulting bandwidth is not sufficient to cover the 2.5 GHz WiMAX band. To achieve sufficiently large bandwidth to cover all the 2.4/5.2/5.8 GHz WLAN and 2.5/3.5/5.5 GHz WiMAX bands, several antennas are proposed, including a microstrip-fed rectangular monopole antenna with a large parasitic patch on the back of the substrate [3], a coplanar waveguide (CPW)-fed antenna formed by a triangular monopole and a U-shaped monopole [4], and a CPW-fed monopole antenna with two bent slots [5]. Although the antennas in [3,4] can generate two wide bands to meet the whole WLAN/ WiMAX applications, the dual wideband might cause interference with other communication systems. Moreover, the oversize of the antenna [5] is somewhat large (40 × 40 mm 2 ).In this Letter, the mode method [6] is introduced to design a novel tri-band monopole antenna covering all the 2.4/5.2/5.8 GHz WLAN and 2.5/3.5/5.5 GHz WiMAX bands. The proposed antenna has a small size of 25 × 36 mm 2 , which is smaller than the antenna proposed in [5]. Meanwhile, compared with the antennas presented in [1,2], the proposed antenna is much simpler in structure. The antenna is designed and optimised by using the electromagnetic simulation tool ANSYS HFSS 13. Details of the antenna design and the simulated and measured results are presented and discussed.

Enhancement of gain with corrugated Y‐shaped patch antenna for triple‐band applications

“…A monopole CPW‐fed antenna is proposed in Ref. for WLAN/WiMAX applications for triple‐band. The triple‐band achieved by etching of inverted L‐slot on rectangular loaded strip line with adjusting structural dimensions and positions.…”

A high FoM monopole antenna with asymmetrical L‐slots for WiMAX and WLAN applications

“…With the rapid development of handheld devices, there is a great demand to design multiband antennas for WiMAX and WLAN applications . Specified spectrum for WiMAX is 2.5 GHz (2.5–2.69 GHz), 3.5/5.5 GHz (3.4–3.69, 5.25–5.85 GHz) and for WLAN it is 2.4 GHz (2.4–2.484 GHz), 5.2/5.8 GHz (5.15–5.35, 5.725–5.825) .…”

“…In Refs. and , a rectangle‐loaded monopole antenna with inverted‐L slot and an inverted‐L shaped radiating element with parasitic element in the ground plane has been used, respectively. In Ref.…”

A Compact Triangular Slot Array Multiband Antenna for Wireless Applications

“…Therefore, asymmetric CPW-fed antenna are used to improve the bandwidth [3]. Meanwhile, CPW-fed is the most popular feeding structures adopted in recent literatures [4][5][6]. In order to better achieve the multiband and miniaturization, many technologies have been studied, such as coupling feed technology [7][8][9], slot loaded technology [10][11], loading the matching network [12], and loading printed distributed inductance technology [13] and fractal technology [14].…”