A compact triple-band H-shaped slot antenna fed by microstrip coupling is proposed. Four resonant modes are excited, including a monopole mode, a slot mode, and their higher-order modes, to cover GPS (1.575 GHz) and Wi-Fi (2.4-2.485 GHz and 5.15-5.85 GHz), respectively. Sensitivity study of the slot geometry upon the resonant modes have been conducted. The measured gains at these four resonant frequencies are 0.2 dBi, 3.5 dBi, 2.37 dBi, and 3.7 dBi, respectively, and the total efficiencies are -2.5 dB, -1.07 dB, -3.06 dB, and -2.7 dB, respectively. The size of this slot antenna is only 0.24λ0×0.034λ0, where λ0 is the free-space wavelength at 1.575 GHz, hence is suitable to install on notebook PC's and handheld devices.

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Compact Multi-Band H-Shaped Slot Antenna

A compact open-slot antenna for bandwidth enhancement is presented. Multiple resonances are generated by using an asymmetrical rectangular patch with the U-shaped open-slot structure. Two bevels are cut on the patch to improve the impedance matching. The proposed antenna provides a wide impedance bandwidth of 122% from 2.95 to 12.1 GHz with -10-dB return loss. It is shown that the impedance bandwidth can be enhanced from 28% to 122% by using different antenna types. Moreover, this slot antenna is with a small size of 24.5 × 24.5 × 1 mm3, while maintaining the ultrawideband (UWB) performance.

Compact Open-Slot Antenna With Bandwidth Enhancement

A compact design of a dual-band (2.4-2.485 GHz and 5.15-5.825 GHz) slot antenna is proposed for WLAN applications. To achieve compact and practical design, the proposed antenna is composed of narrow slots, and placed in the 10 times 10 mm2 corner region on a typical FR4 printed circuit board for WLAN personal-digital-assistance (PDA) phones. The detailed design considerations are described in this communication. Also, simulation and measurement regarding the reflection coefficient and radiation pattern are conducted. Good agreement between both results is obtained.

Compact Dual-Band Slot Antenna at the Corner of the Ground Plane

Since the release by the Federal Communications Commission (FCC) of a bandwidth of 7.5GHz (from 3.1GHz to 10.6GHz) for ultra wideband (UWB) wireless communications, UWB is rapidly advancing as a high data rate wireless communication technology. As is the case in conventional wireless communication systems, an antenna also plays a very crucial role in UWB systems. However, there are more challenges in designing a UWB antenna than a narrow band one. A suitable UWB antenna should be capable of operating over an ultra wide bandwidth as allocated by the FCC. At the same time, satisfactory radiation properties over the entire frequency range are also necessary. Another primary requirement of the UWB antenna is a good time domain performance, i.e. a good impulse response with minimal distortion. This thesis focuses on UWB antenna design and analysis. Studies have been undertaken covering the areas of UWB fundamentals and antenna theory. Extensive investigations were also carried out on two different types of UWB antennas. The first type of antenna studied in this thesis is circular disc monopole antenna. The vertical disc monopole originates from conventional straight wire monopole by replacing the wire element with a disc plate to enhance the operating bandwidth substantially. Based on the understanding of vertical disc monopole, two more compact versions featuring low-profile and compatibility to printed circuit board are proposed and studied. Both of them are printed circular disc monopoles, one fed by a micro-strip line, while the other fed by a co-planar waveguide (CPW). The second type of UWB antenna is elliptical/circular slot antenna, which can also be fed by either micro-strip line or CPW. The performances and characteristics of UWB disc monopole and elliptical/circular slot i antenna are investigated in both frequency domain and time domain. The design parameters for achieving optimal operation of the antennas are also analyzed extensively in order to understand the antenna operations. It has been demonstrated numerically and experimentally that both types of antennas are suitable for UWB applications.

Antenna study and design for ultra wideband communication applications

This communication proposes a compact U-shaped slot antenna with a coupling feed for 4G handset applications. The antenna is composed of a simple open-end U-shaped slot and a feeding line with an antenna area of 58 mm × 12 mm. Two types of resonant modes are excited, including slot mode and monopole mode. Parametric studies on the slot geometry have been demonstrated. By controlling the related parameters, the bandwidth of this antenna can potentially cover the mobile bands of LTE Band 12 (698-742 MHz)/DCS (1710-1880 MHz)/PCS (1850-1990 MHz)/UMTS (1920-2170 MHz)/LTE Band 40 (2300-2400 MHz)/Band 41 (2496-2690 MHz)/Band 42 (3400-3600 MHz)/Band 43 (3600-3800 MHz). Good radiation characteristics, like gain and radiation efficiency are obtained over these operating bands. This antenna is suitable for the metal casing of handheld devices.

https://ir.nctu.edu.tw:443/bitstream/11536/23813/1/000331294800047.pdf

Compact Antenna With U-Shaped Open-End Slot Structure for Multi-Band Handset Applications

We propose a new design of a broadband printed triangular slot antenna. By introducing a small rectangular slot protruding from the triangular slot, a new resonant mode in the vicinity of the fundamental resonant mode of the triangular slot can be excited. Also, good impedance matching of both the fundamental and the new mode can be obtained, which leads to the antenna having a much enhanced operating frequency bandwidth. In addition, by adjusting the structure of the microstrip-line feed near the side perpendicular to the microstrip line, a very broadband operation can be obtained. In general, the obtained broadband bandwidth can be more than four times that of a conventional printed wide rectangular slot antenna (/spl sim/20%). In the proposed design, an impedance bandwidth of about 84% has been obtained. Antenna designs and typical experimental results of the proposed antenna are shown and discussed.

Broadband design of the printed triangular slot antenna

In recent years, wireless communications have progressed very rapidly. Wide-band antenna and multi-band antenna designs have become very important for wireless communications. Several promising monopole antennas for WLAN and WiMax applications have been reported recently. According to the WiMax protocol, there is three bands have been allocated for WiMax application: the lower band is 2.5-2.69 GHz, the middle band is 3.3-3.8 GHz, and the higher band covers from 5.25 GHz to 5.85 GHz. In practical use of WiMax applications, the lower band and the middle band are very close to each other, which lead to cause large effects of coupling and interference. To reduce the coupling and interference between the lower and middle bands, filters must be attached to the antenna to suppress the dispensable bands. However, the cost and the overall antenna size are increased due to the attached filters. In this paper, a CPW-fed printed monopole antenna for dual-band operation of 2.3-4.15 GHz and 4.93-5.83 GHz are proposed. Furthermore, by etching a pair of slits on the proposed monopole antenna, band rejection of frequency range from 2.93 GHz to 3.12 GHz can be achieved. Results show that, this novel design of CPW-fed monopole antenna is suitable for both WLAN and WiMax applications.

Novel design of printed monopole antenna for WLAN/WiMAX applications

In this article, a novel design of non-symmetric ground /spl lambda//4 open slot antenna with microstrip-line is proposed. Choosing the proper dimension of the rectangular conducting plate which connected to the open end of the 50-/spl Omega/ microstrip-line with printed on the opposite side of the FR4 substrate and open slot, one can obtain wide impedance bandwidth and miniaturized antenna area. The proposed antenna printed on FR4 and fed by 50-/spl Omega/ microstrip-line is investigated. The frequency range of the proposed antenna is about 2.2 /spl sim/ 6.1 GHz (94%), which can be applied to mobile wireless communication products on WLAN, Bluetooth and UWB.

Broadband design of the non-symmetric ground /spl lambda//4 open slot antenna with small size

In this paper, a novel dual-band rejected design for cross semi-elliptic monopole antenna is proposed and experimentally studied. The proposed antenna consists of a ultra-wideband cross semi-elliptic monopole antenna and the H-shaped slots, producing dual band-rejected characteristics and maintaining wideband performance and good omni-direction radiation. Therefore, this technique is suitable for creating multi-wideband antenna or for creating ultra-wideband (UWB) antenna with dual rejected-band. Details of the results for the proposed antenna are presented and discussed.

http://ieeexplore.ieee.org/iel5/4395409/4395410/04395657.pdf

A dual-band rejected cross semi-elliptic monopole antenna

The printed heart monopole antenna with bandwidth larger than 10 GHz has been proposed. In the case, the impedance bandwidth of about 137% has been obtained. The impedance bandwidth and peak gain obtained for the proposed antenna is better than the printed circular disc monopole antenna. And, the size of the proposed antenna is also smaller than the printed circular disc monopole antenna.

Wen-Shan Chen

Papers

Broadband design of the printed triangular slot antenna

Novel design of printed monopole antenna for WLAN/WiMAX applications

Broadband design of the non-symmetric ground /spl lambda//4 open slot antenna with small size

A dual-band rejected cross semi-elliptic monopole antenna

A study of the printed heart monopole antenna for IEEE 802.16a/UWB applications