Printed folded flared monopole antenna

Applied is a folding procedure to the conductor of a wideband triangular/flared printed monopole to yield an electrically smaller radiator that does not significantly compromise the gain or the return loss bandwidth of the antenna. The technique is useful for applications where the volume for the radiator is constrained. A theoretical and experimental investigation of the antenna is given.     

A broad-banded folded monopole antenna

Electrically short folded monopole antennas with lumped mutual coupling between driven and folded sections are considered, showing that the input radiative impedance exhibits a resonance frequency depending upon the sign and magnitude of the coefficient of coupling. If extended to "n-folded" monopoles with separate lumped mutual couplings, the analysis shows the input radiative impedance will exhibitnstaggered resonance frequencies and bandwidth broadening.     

Multiband folded planar monopole antenna for mobile handset

This paper introduces a folded planar monopole antenna, which has a very low profile of about one twentieth of the wavelength of the lowest operating frequency. The effect is achieved by using a bended rectangular radiating patch and an inverted L-shape ground plane. The proposed antenna can be used in multiband operation, with omnidirectional radiation patterns for all operating bands. Its impedance bandwidth, determined by 10 dB return loss, covers almost all present wireless communication systems: Global System for Mobile Communication (GSM), Digital Communication System (DCS), Personal Communication System (PCS), Universal Mobile Communication System (UMTS), and Industrial Science Medical (ISM) band. This paper presents the design and experimental results of the proposed antenna. Moreover, the study also investigates the tuning effects of the geometry parameters on impedance matching.     

Planar meander sleeve monopole antenna for DVB-H/GSM mobile handsets

A novel planar meander sleeve monopole antenna for digital video broadcasting-hand held (DVB-H) and GSM mobile handsets is presented. By using the planar sleeve monopole type radiating element constructed with meander strips, the antenna provides a degree of miniaturisation while retaining a wide bandwidth covering the DVB-H and GSM-900 bands. A prototype is constructed and tested, which shows that an impedance bandwidth of 498 MHz (463-961 MHz) within 2.5:1 VSWR is achieved.     

A low-profile planar monopole antenna for multiband operation of mobile handsets

A novel planar monopole antenna is proposed. It has a very low profile (antenna height less than 0.04 times the operating wavelength in free space) and is capable of multiband operation. The proposed antenna has a planar rectangular radiating patch in which a folded slit is inserted at the patch's bottom edge. The folded slit separates the rectangular patch into two subpatches, one smaller inner subpatch encircled by the larger outer one. The proposed antenna is then operated with the inner subpatch resonating as a quarter-wavelength structure and the outer one resonating as both a quarter-wavelength and a half-wavelength structure. The proposed antenna, 12 mm high and 30 mm wide, has been constructed, and the obtained bandwidths cover the global system for mobile communication (890-960 MHz), digital communication system (1710-1880 MHz), personal communication system (1850-1990 MHz), and universal mobile telecommunication system (1920-2170 MHz) bands. Details of the proposed design and obtained experimental results are presented and discussed.     

Compact monopole antenna for GSM/DCS operation of mobile handsets

A novel dual-frequency monopole antenna, with a low profile and also with a small transverse size, is proposed. Firstly, by investigating and utilising a taper meander line antenna with a very large vertex angle, the antenna height is reduced to 15 mm. Secondly, by wrapping it in a box-like structure, the antenna transverse width is reduced to 12 mm. Thirdly, by introducing another geometrically complementary meander line branch, the second resonant mode is enhanced. Finally an antenna with dimensions of 15/spl times/12/spl times/7 mm is designed, and good impedance bandwidth performance for GSM (890-960 MHz) and DCS (1710-1880 MHz) bands is observed.     

Shorted, folded planar monopole antenna for dual-band mobile phone

A novel shorted, folded planar monopole antenna for application in GSM/DCS dual-band mobile phones is proposed. The antenna is easily fabricated from stamping a single metal plate, which is then folded onto a foam base of compact size 5/spl times/10/spl times/40 mm/sup 3/. In addition, the proposed antenna shows a very low profile of 5 mm protruded from the top edge of the system ground plane, making it very promising to be employed within the casing of a mobile phone as an internal antenna.     

Dual band folded monopole/loop antenna for terrestrialcommunication system

With the introduction of DCS1800 to meet the demands for a wider frequency spectrum for mobile communication systems, novel antenna structures capable of generating dual resonance are in demand. An antenna structure based on the geometry of a bent folded monopole antenna capable of dual resonance frequencies operation is discussed. This antenna is able to cover the GSM/DCS 1800 communication system bands     

A monopole antenna loaded with a modified folded dipole

A traveling-wave distribution of current can be produced on a linear antenna by inserting a resistance of suitable magnitude one-quarter wavelength from its end. In this study the resistor is replaced with a modified folded dipole which has a radiation resistance approximately equal to that of the matching resistor. Thus the input section has a traveling wave distribution up to the inserted antenna, as before, but now the power that was previously dissipated in the resistor is also radiated. Input impedance, current distribution, and radiation patterns of this antenna are computed, and input impedance and radiation patterns are also measured. Horizontally polarized patterns are similar to those of a horizontal dipole over a ground plane, and vertically polarized patterns in a plane orthogonal to the folded element are similar to those of a monopole over a ground plane. Coverage is also obtained in the zenith direction in the plane of the folded element, as long as it is not an integral number of half wavelengths above the ground plane. The peaks and nulls can be controlled by adjusting the monopole height accordingly and it is possible to achieve near hemispherical coverage     

Dual-frequency planar antenna for handsets

Cellular telephone handsets are now being designed to have dual-mode capabilities. In particular, GSM and DCS1800 modes are used in Europe. And PCS and AMPS modes are used in the USA. A novel planar dualband internal antenna for handsets which operates in the ~0.9 and 1.8 GHz bands is proposed. The dualband antenna has almost the same size as a conventional internal antenna operating in the 0.9 GHz band. Good dual-band operation was obtained for frequency ratios in the range 1.3-2.7     

Small broadband disc-loaded monopole antenna with probe feed and folded stripline

A small broadband disc-loaded monopole antenna with a probe feed and folded stripline is presented. The antenna is composed of a rectangular disc with multiple shorting pins and a probe feed with a folded stripline that are coupled electromagnetically. The dimensions of the proposed antenna are 12/spl times/12/spl times/10 mm, and it has a measured impedance bandwidth of 700 MHz for VSWR <2 with a centre frequency at 2.54 GHz, which is approximately 27.5% of a fractional bandwidth.     

Broadband multilayer ceramic chip antenna for handsets

A novel broadband and small multilayer ceramic chip antenna has been designed and investigated. The proposed antenna has a small size of 14×2.4×1 mm³. A wide bandwidth of 33% (VSWR<2.0) has been obtained, and the measured antenna gain has an average value of ~1.2 dBi. These characteristics make the proposed antenna applicable to future mobile handsets     

一种用于手持移动终端的九频段平面印制天线

提出了一种应用于手持移动终端的九频段平面印制天线,该天线结构紧凑,尺寸为20 mm×28 mm×0.8 mm.利用弯折单极子、寄生地枝和耦合分枝激励起了五个谐振模式,并通过三个调节片和位于馈电点附近的阶梯形过渡结构改善了各个谐振模式的阻抗匹配,从而拓展了天线的工作带宽通过分析该天线关键参数对带宽性能的影响,对关键参数进行了优化,得到了满足性能要求的天线结构.天线样品的实测-6 dB阻抗带宽为700～1 008 MHz和1 692～2 984 MHz,覆盖了LTE700/2300/2500,GSM850/900,DCS/PCS/UMTS和2.4-GHz WLAN频段;工作频带内具有良好的辐射性能     

Printed antenna suitable for mobile communication handsets

A printed antenna consisting of an annular ring coupled to a shorted patch is presented. The size of the antenna is compatible with typical mobile communications handset terminals and its impedance bandwidth satisfies the requirements for such systems as broadband personal communications systems (PCS)     

MF AM folded monopole characteristics

Folded monopole antennas have been used for many years in medium frequency amplitude modulation broadcast applications. These antennas offer a grounded radiating structure with a height approximating a quarter wavelength. Folded monopoles have been studied exhaustively during a previous effort in an attempt to characterize the input impedance and directivity characteristics as a function of monopole height. As a result it was observed that several impedance regions can be achieved as a function of antenna height and cage diameter: Some of these regions permit a bandwidth operation sufficiently broad to support a high fidelity response for analog or digital transmissions. This type of antenna can be useful at different heights including a self matching region at the standard 50 ohms impedance. By choosing the appropriate antenna physical dimensions, antenna tuners can be avoided and thus it increases efficiency. Measurements have been made on a full scale 72 meter tower with a 6 wire cage in order to validate the calculated antenna input impedance and directivity. The cage and supporting mast make up the equivalent of a transmission line. For this reason different standard triangular towers were analyzed in order to determine their effect on the input impedance. Tower effective radius is determined taking into account the tower width and the tower leg diameter. At the same time, a minimum antenna height with maximum efficiency has been analyzed to solve the hard problem for installations at places where antenna height is a challenge for the designer.     

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.     

Small internal ceramic chip antenna for IMT-2000 handsets

A small internal ceramic chip antenna for IMT-2000 handsets is investigated experimentally and numerically. It has a bandwidth of about 14%, measured gain of 1.3 dBi, and an omnidirectional radiation pattern similar to that of a monopole antenna. These features make the proposed antenna suitable for handset applications.     

Optoelectronically reconfigurable monopole antenna

A monopole antenna is reconfigured for 200 or 375 MHz bands by optoelectronically switching two segments together. Light levels of much less than 1 mW significantly change the antenna pattern and gain.<>     

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.