Wideband tri-plate monopole antenna

A novel wideband tri-plate monopole antenna comprising three folded rectangular plates spaced by 120/spl deg/ and connected together at the antenna's central axis is presented. The antenna occupies a small cross-sectional area of 10 mm in diameter and yet provides a large bandwidth of >10 GHz (about 2.7-12.9 GHz here). In addition, the antenna shows improved omnidirectional radiation patterns across the passband.     

宽带平面单极天线

提出了一种宽带平面单极天线,其辐射单元为底部具有斜切角的矩形铜片,馈电点偏离辐射单元的中心位置,斜切角和不对称馈电的应用有效地扩展了带宽.用Ansoft HFSS软件对天线尺寸、斜切角和馈电点位置等参数对天线特性的影响作了分析,给出了这些参数的最佳值,并根据这些最佳参数制作了天线样机.以电压驻波比小于3.5:1为标准,实测得到的天线带宽为70～3000 MHz.电压驻波比和方向图的测量结果与仿真结果吻合较好.     

Small dual L-shaped printed antenna

A novel shorted dual L-shaped printed antenna is presented. The antenna consists of two L-shaped shorted patches and a feed network with a 180/spl deg/ phase difference applied to each antenna probe, etched on a high dielectric substrate located beneath the ground plane. A 10 dB return loss bandwidth of 16.6% has been achieved. The measured cross-polarised fields are 15 dB below the co-polarised levels     

Wideband monopole antenna for DVB-T applications

A novel asymmetric fork-like monopole antenna for digital video broadcasting-terrestrial (DVB-T) signal reception for application in the UHF band is presented. The proposed antenna consists of two two-branch strip monopoles on a rectangular ground plane with a concave. The concavity in the ground pattern serves as an effective means for the gap between the radiating element and the ground plane for impedance matching. The influence of various parameters on antenna characteristics has been investigated. Results show a wide bandwidth of 461 MHz (451?912 MHz) or 70% of DVB-T centred frequency (655 MHz). The proposed antenna has omnidirectional radiation patterns in the yz-plane. Details of the proposed antenna design and experimental results of the constructed prototypes are presented.     

共面波导馈电的频率可重构印刷单极子天线

提出了一种间接改变天线辐射体长度的方法。该方法通过改变天线馈线中地导体的长度,间接地改变天线辐射体的长度,有效避免了有源开关对天线辐射性能的影响。为验证此方法,设计了一个共面波导馈电的频率可重构印刷单极子天线,该天线利用PIN二极管来改变馈电端地的长度。实验结果表明:控制开关的工作状态,可使天线的谐振频率发生明显的变化。相应的中心频率分别为1.9 GHz和2.3 GHz,相对阻抗带宽分别为20.8%和17.2%。     

Wideband stubby monopole antenna for mobile phone

A novel stubby monopole antenna fabricated using a single metal plate is presented. A prototype of the proposed antenna with a cross-sectional area of 10/spl times/10 mm and a length of 20 mm is implemented, and the antenna shows a wide operating bandwidth of about 10.9 GHz, making it easy to cover the UMTS band and the 2.4/5.2/5.8 GHz WLAN bands for mobile/WLAN dual-mode operation of a mobile phone.     

Wideband microstrip-fed monopole antenna having frequency band-notch function

A novel and compact ultra-wideband (UWB) microstrip-fed monopole antenna having frequency band notch function is presented. To increase the impedance bandwidth of an antenna, a narrow slit is used. By inserting a modified inverted U-slot on the proposed antenna, the frequency band notch characteristic is obtained. The designed antenna satisfies the voltage standing wave ratio requirement of less than 2.0 in the frequency band between 3 and 11 GHz while showing the band rejection performance in the frequency band of 5.0 to 5.9 GHz.     

Wideband monopole antenna for various mobile communication applications

A small, wideband microstrip-fed monopole antenna for mobile communication systems, is designed. The antenna has a wide bandwidth ranging from 1.65 to 10.6 GHz for S/sub     

Compact dual-band printed monopole antenna for WLAN application

A microstrip-fed dual-band antenna with omnidirectional radiation patterns in the azimuth plane is proposed. It can provide two separate impedance bandwidths of 0.25 GHz (2.3-2.55 GHz) and 0.85 GHz (5.1-5.95 GHz), so that it easily covers the required bandwidths for wireless local area network applications. The proposed antenna is composed of a rectangular monopole and a folded strip whose end is coupled to the monopole by a narrow gap. It occupies an area of only 6.5 times 14 mm when printed on an FR4 substrate with a thickness of 1.5 mm.     

Wideband CPW-fed monopole antenna with parasitic elements and slots

A novel compact and wideband coplanar waveguide(CPW)-fed monopole antenna is proposed. To increase the impedance bandwidth, two parasitic elements and three slots are added, which structures are optimised by a parametric analysis. The antenna operates over 3.1 to 11 GHz for the return loss of less than -10 dB. Radiation patterns also show very well omnidirectional performance of the proposed antenna.     

一种改进型折叠条带带陷UWB印刷单极子天线

为满足短距离无线通信系统的要求,设计并实现了一种改进型的超宽带印刷单极子天线,通过在U型辐射臂上对称加载了两个折叠条带,使天线具备了带陷功能,利用HFSS软件详细分析了折叠条带和缝隙的尺寸变化对天线陷波特性的影响。实际制作了天线的实物,测试结果和仿真结果基本吻合。该天线的阻抗带宽可以覆盖3.04~10.95 GHz,阻带范围约为4.95~5.97 GHz,绝对带宽为7.88 GHz,完全具备超宽带性能。在整个工作频段内近似具有全向性,增益曲线平坦,天线的尺寸仅为31 mm×35 mm,结构紧凑,加工方便且容易集成。     

Compact printed ultra-wideband monopole antenna with dual band-notch characteristic

A compact ultra-wideband microstrip-fed planar antenna with dual band-notch characteristic is presented. Two notched frequency bands are achieved by embedding an E-slot in the radiation patch and a U-slot defected ground structure in the feeding line. Moreover, the two notched bands can be controlled by adjusting the length of the corresponding slot. Experimental results show that the proposed antenna, with compact size of 35 x 14 mm, has an impedance bandwidth of 2.87-10.91 GHz for a voltage standing-wave ratio less than 2, except two frequency notched bands of 3.49-4.12 and 5.66-6.43 GHz.     

Single layer printed monopole antenna for dual ISM-band operation

The ability of a single layer strip fed printed monopole, which has a serial-slot and an end-stepped feed-strip, to operate at dual Industrial, Scientific, and Medical-band (2.4 and 5.8 GHz bands) is demonstrated. This antenna combines omni-directional and broad bandwidth in an easy to fabricate structure. Experimental results indicate that the VSWR 2:1 bandwidths achieved were 8.2% and 18.2% at 2.45 GHz and 5.5 GHz. Effects of varying the serial-slot dimensions and the ground-plane size on the antenna performance are also described.     

Compact printed ultra-wideband monopole antenna with dual band-notched characteristics

A compact printed ultra-wideband (UWB) monopole antenna with dual band-notched characteristics is presented. One complementary split-ring resonator (CSRR) is etched inside the patch of the monopole antenna to achieve dual notch frequency bands. A practical example for a UWB antenna (working from 2.90 to 12 GHz) is demonstrated, with one notch frequency band at 3.40-3.48 GHz and the other at 5.40-5.98 GHz. In addition, the effect of the dimensions of the CSRR on the dual notch frequency bands is also analysed.     

Microstrip-fed dual-U-shaped printed monopole antenna for dual-band wireless communication applications

A microstrip-fed dual-U-shaped printed monopole antenna design for wireless communication applications in the 2.4 and 5.8 GHz bands is presented. This antenna combines omnidirectional, high gain and broad bandwidth in an easy to fabricate structure. Experimental results of the constructed prototype are presented.     

Compact printed monopole antenna with 24:1 impedance bandwidth

A compact tapered CPW-fed hollowed elliptical printed monopole antenna with extremely wide bandwidth is proposed. The results demonstrate that this antenna achieves a measured impedance bandwidth from 0.44 to 10.6 GHz (24.1:1) for VSWR les 2, and exhibits a nearly omnidirectional radiation pattern, while its area is only about 0.18 times 0.13lambda_l, where lambda_l is the wavelength of the lowest operating frequency.