Wideband rectangular slot antenna for personal wireless communication systems

Antenna designs are achieved for wideband operation by the use of a coplanar patch-slot antenna, fed by a coplanar waveguide. This design is easily tuned to operate at 2.45 and 5.75 GHz, with wide bandwidth for wireless systems. The operating frequency is controlled by modifying the patch dimensions. The return loss, input impedance, radiation pattern, directivity, gain, and efficiency of the proposed designs are computed and presented. A parametric study of the antenna is also introduced.     

CPW-fed circular slot antenna with slit back-patch for 2.4/5 GHz dual-band operation

A circular slot antenna fed by a coplanar waveguide (CPW) is proposed for dual-band operations. Dual frequency bands that cover the 2.4 GHz (2400-2484 MHz) and 5 GHz (5150-5825 MHz) bands were obtained by embedding a pair of slits in the circular back-patch that is printed on the backside of the substrate and concentric with the circular slot. This design resulted in broadside far-field patterns with low cross-polarisation levels in both frequency bands and a small antenna size of 40/spl times/40 mm with the ground plane regarded as part of the antenna structure.     

Analysis of L-shaped slot cut broadband rectangular microstrip antenna

Broadband microstrip antenna (MSA) is realised by cutting the slot at an appropriate position inside the patch. The bandwidth (BW) of the rectangular MSA (RMSA) has been increased by cutting an L-shaped slot inside the patch and it gives a BW of more than 550?MHz (>25%). The reported antenna has a peak gain of 9?dBi which reduces to less than 4?dBi towards the higher frequencies of BW. In this article, an analysis to study the broadband response of the L-shaped slot-cut RMSA is presented. Through the analysis, it was observed that the slot does not introduce any mode but modifies the orthogonal and higher-order TM₁₁ and TM₂₀ mode resonance frequencies of the patch and along with the TM₀₁ mode realises broader BW. Since TM₁₁ mode is dominant towards the higher frequencies of the BW, the cross-polarisation levels increases, which reduces the antenna gain to less than 4?dBi.     

57 GHz Gaussian beam antenna for wireless broadband communications

The radiation characteristics of a millimetre wave Gaussian beam antenna (GBA) have been investigated theoretically and experimentally. The antenna consists of a fused-quartz half-wavelength piano-convex Fabry-Perot resonator fed by pyramidal horn. Very low sidelobe levels (<-35 dB) and a fairly good efficiency (>50%) are obtained at 57.2 GHz. Such an antenna configuration is therefore suitable for wireless broadband communications     

Frequency notched wide slot antenna for UWB/2.4 GHz WLAN applications

A compact frequency notched microstrip slot antenna for ultra-wideband (UWB) /2.4 GHz-band wireless local area network (WLAN) applications is proposed. The antenna is similar to a conventional microstrip slot antenna; however, by introducing a cross wide slot and a meandered-slotted stub, both compact size and frequency notched function can be achieved. It has been studied both numerically and experi- mentally for its impedance bandwidth, surface current distribution, radiation patterns, and gain. As will be seen, an operation bandwidth of over 4.61 ranging from 2.39 to 11.25 GHz for return loss lower than having a frequency notched band ranging from 4.75 to 5.85 GHz has been achieved, and good radiation performance over the entire frequency range has also been achieved.     

Surface-mount dual-loop antenna for 2.4/5 GHz WLAN operation

A surface-mount dual-loop antenna suitable for dual-frequency WLAN operation is presented. For achieving dual-frequency operation with a compact size, the antenna comprises two loop strips of different sizes printed on a flexible printed circuit board, which is then bent and attached onto a foam base of compact size. The antenna shows an attractive feature of high antenna gain, about 4 and 5 dBi for frequencies across the 2.4 and 5 GHz WLAN bands, respectively.     

Compact dualband rectangular microstrip patch antenna for 2.4/5.12-GHz wireless applications

A dual-band antenna is proposed for WLAN and WiMAX frequency bands. Two resonance frequencies are found to be 2.45 and 5.125 GHz and ?10 dB bandwidth of lower and upper resonance frequencies are 4.13 and 8.82 % respectively. It is observed that frequency ratio is more sensitive with the dimensions of L-shaped slot. The frequency ratio of the antenna for a given dimension of L-slot is found to be 2.092 and gain of the antenna is 3.9 dBi for lower resonance whereas 6 dBi at upper resonance. The theoretical results are compared with the reported experimental result as well as simulated results obtained from IE3D simulation software which are in close agreement.     

Modified inverted-L monopole antenna for 2.4/5 GHz dual-band operations

A novel compact modified inverted-L monopole antenna for dual-band operation is proposed. The proposed antenna is designed to operate in 2.4 GHz (2400-2484 MHz) and 5 GHz (5150-5825 MHz) bands for WLAN applications in IEEE 802.11a/b and HIPERLAN/2 systems. The method to realise the desired dual-band operation is by introducing a meandered wire and a conducting triangular section to a conventional inverted-L monopole, which results in a small antenna size of 7/spl times/18 mm/sup 2/. Good impedance bandwidth performance is also observed.     

Compact CPW-fed monopole antenna for 5 GHz wireless application

A compact and simple coplanar waveguide (CPW)-fed monopole antenna for 5 GHz wireless communication is proposed. By properly adjusting the lengths of both the monopole strip and the inverted L-shaped ground, the designed antenna, with, including ground plane, only 9/spl times/9.5 mm/sup 2/, can operate at the desired 5.2 or 5.8 GHz band. The electromagnetic coupling effect between the radiating strip and the ground on excitation of the resonant mode has been studied. Prototypes of the proposed antenna have been constructed and experimentally studied. Measured results show a -10 dB impedance bandwidth and an average antenna gain of 400 MHz and >6 dBi, respectively.     

低功耗2.4GHz无线通信系统的设计与实现

低功耗、微型化是当前无线通信产品尤其是便携产品的迫切要求。本文提出了一种工作在2.4GHz ISM频段的无线传输系统的设计方案。该方案主要采用Nordic公司最新推出的射频芯片nRF24E1,设计并实现了一种近距离、低功耗的无线通信收/发系统。     

Printed compact dual band antenna for 2.4 and 5 GHz ISM band applications

A printed compact dipole antenna for dual ISM band (2.44 and 5 GHz) is presented. The proposed antenna fed by using a 50 /spl Omega/ coaxial line occupies a volume of 15/spl times/40/spl times/1 mm/sup 3/ (FR-4, permittivity 4.6). The impedance bandwidth for 10 dB return loss is about 400 MHz (from 2170 to 2570 MHz) at 2.4 GHz band and over 2300 MHz (from 4690 to beyond 7000 MHz) at 5 GHz band. The measured radiation gains range from 1.20 to 1.41 dBi at 2.4 GHz band and from 2.25 to 3.44 dBi at 5 GHz band, respectively.     

Compact wideband antenna for 2.4 GHz WLAN applications

A novel compact wideband antenna for wireless local area network (WLAN) applications in the 2.4 GHz band is presented. The proposed low profile antenna of dimensions 15/spl times/14.5/spl times/1.6 mm offers 18.6% bandwidth and an average gain of /spl sim/5 dBi. The antenna can be excited directly using a 50 /spl Omega/ coaxial probe.     

Narrow flat-plate antenna for 2.4 GHz WLAN operation

A novel flat-plate antenna, obtained by cutting an inverted-L slit in a narrow metal plate or by stamping from a metal sheet, for wireless local area network (WLAN) operation in the 2.4 GHz band (2400-2484 MHz) is presented. The antenna has a simple structure and is easily fed by using a 50 /spl Omega/ coaxial feed line. A prototype of the proposed antenna with a narrow width of 3 mm is constructed and studied.     

HiperLAN2: broadband wireless communications at 5 GHz

Solutions for high data rates and local coverage have been developed over a couple of years in the area of wireless local area networking. The quality of service, security, mobility, and high throughput are key components that drive the standards for broadband wireless multimedia communications presently being developed in Europe as well as in the United States and Japan for the 5 GHz band. These technologies are well suited to complement third-generation cellular networks. HiperLAN type 2 (HiperLAN2) is one of these systems, which is being specified by the ETSI project BRAN. The core parts of the specification were finalized at the end of 1999. Almost total harmonization has been achieved between the standardization bodies in Europe and Japan (ETSI and ARIB, respectively). HiperLAN2 will provide data rates up to 54 Mb/s, and is intended for local communications in indoor and outdoor environments. An overview of the HiperLAN2 standard is presented together with exemplary link and system performance results     

Sheetlike Waveguide for 2.4 GHz and 5 GHz Bands

We present a useful design for a free access mat which supports two frequency bands of 2.4 GHz and 5 GHz. The free access mat is a sheet‐shaped waveguide which consists of a tightly coupled double‐layered microstrip resonator array. It provides easy access for devices in short‐range wireless communications. Interference is a common problem with conventional applications which use free space transmission. Our proposed wireless access system uses a subsidiary waveguide, the free access mat. Wireless devices are proximately coupled to the free access mat through which the coupled electromagnetic (EM) wave transmits. The arrival domain of the EM wave of an application is therefore limited to an area close to the free access mat. Wireless devices can be coupled to the free access mat at an arbitrary position without contact. We previously presented a free access mat for a single frequency band. This paper presents a free access mat for the two frequency bands of 2.4 GHz and 5 GHz. The free access mat uses a ring patch resonator array which is easily excited by typical antennas and is resistant to interference. These characteristics are demonstrated by numerical simulation and confirmed by experiment.     

一种小型宽频带缝隙天线的设计

设计一种结构新颖紧凑的小型宽频带(带宽10 GHz)微带天线。以24 mm×23 mm×1.6 mm的FR4为基底,在基底接地面中心位置设计一个正六边形和一个对称的十字交叉型贴片组成的缝隙来增大工作带宽,基底另一侧是一条微带线。用电磁仿真软件Ansoft HFSS对该天线进行模型仿真和结构优化,并进行加工和测试。结果显示该天线工作频段覆盖3.6～13.6 GHz,阻抗带宽为116%,辐射特性良好,给出了反射损失曲线和辐射方向图,测试结果与仿真结果基本相同,为宽频带无线通信的研究提供了一定的参考。     

Wide-band high-efficiency printed loop antenna design for wireless communication systems

A new wide-band high-efficiency coplanar waveguide-fed printed loop antenna is presented for wireless communication systems in this paper. By adjusting geometrical parameters, the proposed antenna can easily achieve a wide bandwidth. To optimize the antenna performances, a parametric study was conducted with the aid of a commercial software, and based on the optimized geometry, a prototype was designed, fabricated, and tested. The simulated and measured results confirmed that the proposed antenna can operate at (1.68-2.68 GHz) band and at (1.46-2.6 GHz) band with bandwidth of 1 and 1.14 GHz, respectively. Moreover, the antenna has a nearly omnidirectional radiation pattern with a reasonable gain and high efficiency. Due to the above characteristics, the proposed antenna is very suitable for applications in PCS and IMT2000 systems.     

Printed antenna with folded non-uniform meander line for 2.4/5 GHz WLAN bands

A low profile dual-band antenna for WLAN applications is proposed. It has the folded non-uniform meander line with the impedance bandwidth of 140 MHz at the 2.4 GHz band and 1500 MHz near 5 GHz with VSWR below 2, and an omnidirectional radiation pattern is obtained.