Method for measuring user-induced load on mobile terminal antenna

A method for measuring user-induced load on a triple-band GSM PIFA antenna is presented. The capacitance, total efficiency and matching of the antenna were measured in terms of the increased load of a phantom hand. Up to 10% tuning of the centre frequency occurred, with from 52 to 15% decreased total efficiency owing to the undesired hand grip. The comparable capacitance increased proportionally from 3.83 to 4.45 pF, allowing evaluation of the magnitude of the load.     

Single and double layer planar multiband PIFAs

A compact multiband planar inverted-F antenna (PIFA) suitable for distributed radio-over-fiber repeater networks is modified into a planar structure. It is shown that the planar antenna performance is not degraded with respect to the original PIFA and further, a two layer design is demonstrated to offer improved feed matching. The European bands for GSM, DCS-1800, DECT, UMTS, Bluetooth and HiperLAN2 are all covered. A model of the antenna is introduced as a first stage to developing an equivalent circuit.     

A Tunable Via-Patch Loaded PIFA With Size Reduction

A novel tunable planar inverted-F antenna (PIFA) is described. A via-patch is introduced under the main radiating element to create a capacitive coupling effect and lower the operating frequency. The antenna size is reduced by half when compared to the conventional PIFA. Incorporating with an L-shaped opening on the ground plane, the proposed via-patch loaded PIFA exhibits a 10-dB return-loss bandwidth of 8.91% for 2.4 GHz ISM band applications. In the proposed approach, the capacitive patch is connected to the ground through a via while a coaxial feed is directly connected to the radiating element. This is different from other capacitive-loading, size-reduction schemes in which the capacitive patch is connected to the coaxial feed, thus not able to provide frequency tuning. By simply replacing the via in our antenna with a screw and adjusting the height of the via-patch by turning the screw, a tuning range of 0.8 GHz from 2.5-3.3 GHz can be achieved. This makes the proposed PIFA a convenient tunable small antenna. Both simulation and measurement results are presented together with parametric studies on the via-patch and L-shaped opening ground plane     

New Design of Multi-Band PIFA Antenna with Reduced SAR for Mobile and Wireless Applications

Wireless Personal Communications - In this paper, a new multi-band PIFA antenna covering four frequency bands (GSM, Wifi/Bluetooth, 4G LTE and WIMAX) is presented. The proposed method in this work...     

一种新型三频段内置天线的设计

随着移动终端的小型、多样化的发展,如何设计一个多频段、小尺寸、低剖面的内置天线成为移动终端天线设计的难点。以双分支平面倒F型天线为基础,通过增加寄生的短路分支,利用不同的路径分支激发各自频段的方式,实现在VSWR<3.0内涵盖GSM900、DCS、PCS三个操作频段的一款新颖的内置天线。天线由2个短路柱、1个馈电柱和在天线辐射体上切割裂缝与缝隙构成,并利用仿真环境HFSS进行3D建模与电磁仿真,仿真结果满足三频段天线的性能要求。     

一种新型三频PIFA天线设计

针对天线的多频问题,提出一种新型的三频段平面倒F天线(PIFA天线),该结构采用在辐射贴片上开U形槽和∏形槽来实现。通过HFSS13.0对天线模型进行仿真分析,使得天线最终工作于GSM(890～960 MHz)、DCS(1 710～1 880 MHz)和ISM2 400 MHz(2 400～2 484 MHz)3个频段。仿真结果表明,3个频段的相对带宽分别为10%、6%和11%,能满足通信要求。此外,天线整体辐射性能良好,且结构简单。     

PIFA with PIL patch having bent feed line for GSM=DCS=UMTS=WiBro applications

A novel, low-profile internal planar inverted-F antenna (PIFA) with broadband characteristics is proposed for GSM/DCS/UMTS/WiBro applications. Broadband characteristics are achieved by inserting an inverted-L patch, and a bent feed line ensures good impedance matching. The optimum design parameters of the proposed antenna are decided by parametric analysis. Good omnidirectional patterns with reasonable gains are achieved at each frequency band of interest     

一种双U形槽加载的新型三频平面倒F天线

提出一种新型的三频平面倒F天线结构。通过在矩形贴片上开双U形槽,非常容易获得三频特性,而且可以很方便地实现对三个谐振频率的单独调节。文中设计了一个工作在GSM/DCS/ISM三个频段的平面倒F天线,采用基于矩量法的IE3D软件进行建模、仿真和分析,实测结果与仿真结果相当吻合。此外,由于这种天线只用一个同轴探针馈电,尺寸小并且结构简单,因而容易设计、制作和调节。     

Design and Performance Investigation of a Dual-Element PIFA Array at 2.5 GHz for MIMO Terminal

A study is described of a modified planar inverted-F antenna (PIFA) operating in 2.5 GHz band on a printed circuit board (PCB) of a mobile phone handset. The antenna dimension is reduced substantially with a miniature ground plane and capacitive loading. While inheriting the attractive features of PIFAs, such as low profile, easy fabrication and low cost, the proposed antenna exhibits low coupling to the PCB. A dual-element PIFA array is implemented on a mobile handset PCB and the diversity performance of the dual-element PIFA array is evaluated in both simulation and measurement.     

Frequency-reconfigurable two-port antenna for mobile phone operating over multiple service bands

A frequency-reconfigurable antenna for a mobile phone with small volume is proposed. The proposed antenna consists of a planar inverted F-antenna (PIFA) with volume of 4times36times5timesmm³ and a monopole antenna embedded in the same space. The two antennas are excited by two separate feeds with a common ground plane. A switch is used in the PIFA for frequency-reconfigurable operation. The PIFA can cover either LTE (698-806-MHz) or GSM900 (880-960-MHz) depending on the state of the switch. The monopole antenna can cover either PCS1900 (1.85-1.99-GHz) and m-WiMAX (3.4-3.8-GHz) or WLAN 802.11a (5.15-5.35-GHz) depending on the state of the switch. The antenna gain is in the range of -1.99-0.61-dBi over 700-MHz-2-GHz bands and 2.39-4.62-dBi over the bands higher than 3-GHz. The proposed antenna is shown to have good radiation characteristics.     

Frequency notched printed slot antenna with parasitic open-circuit stub

A new frequency notched ultra-wideband microstrip slot antenna with a parasitic tuning stub is proposed. The antenna is similar in configuration to a conventional microstrip slot antenna; by introducing a parasitic open-circuit tuning stub, flexible frequency notched function is achieved. Several properties of the antenna, such as frequency notched function, antenna transfer function and gain, have been investigated. As is reported, the operation bandwidth of the antenna is 2.91-11.16 GHz, in which a frequency notched band of 5.10-5.85 GHz has been achieved. Furthermore, good ultra-wideband linear transmission performance over the entire operation frequency range has also been achieved.     

Dual-resonant π-shape with double L-strips PIFA for implantable biotelemetry

A compact -shape with a double L-strips planar inverted-F antenna (PIFA) is proposed for implantable biotelemetry in the Medical Implant Communication Services band (MICS band). The antenna occupies a volume of only 643 mm³ (22.5 22.5 1.27 mm), operating frequency at 402 MHz. Utilising the -shape with the double L-strips PIFA structure can excite dual-resonate frequencies that control the dual-resonant frequency at 375 and 427 MHz to obtain the broad bandwidth of 80 MHz (362 442 MHz) at return loss of 10 dB. To demonstrate the performance of the implantable antenna more efficiently, the simulating skin fluids are also developed by varying alcohol concentration with salts. Thus, provided is a miniature, broadband implantable PIFA for biotelemetry with medical devices.     

一种基于PIFA结构多频段手机天线的设计

设计了一款基于PIFA结构的手机天线,以多支节和增加寄生单元方式实现天线的小型化和多频段要求。采用HFSS13.0高频电磁仿真软件对天线进行仿真优化,最终得到天线的尺寸为33 mm×13 mm×8 mm,同时天线在多个频点处谐振。仿真结果表明,谐振点位置S11≤-10 dB,天线和馈线匹配良好,天线带宽足够同时覆盖GSM850、DCS1800、PCS1900、LTE2300/2500、ISM/Bluetooth、WLAN(2.4GHz)工作频段。对设计天线进行了加工和实测,实测与仿真结果吻合良好,验证了本设计的可靠性。     

Single-feed dual-band planar inverted-F antenna with U-shaped slot

The development of small integrated antennas plays a significant role in the progress of rapidly expanding wireless communication applications. This paper describes a novel dual-band planar inverted-F antenna (PIFA) for wireless local area network applications. The proposed PIFA uses single feed only. A novel top-plate geometry, a U-shaped slot, is discussed. An example is given for this novel slot shape for frequency bands of 2.4 and 5.2 GHz. Simulation based upon the method of moments (MoM) is used to model the performance of the antenna. Comparisons with results measured on fabricated antenna structures are provided for simulations validation.     

一种U型开槽的平面倒置F型双频微带天线

提出一种新型U型开槽的平面倒置F型双频微带天线(PIFA)，该天线利用单馈点同轴线馈电，辐射贴片尾端折叠的设计方式，其结构实现了微带天线在无线通信中小型化双频段工作的要求。利用著名的ANSOFF公司的仿真软件HFSS8．0(High Frequency Structure Simulator)进行仿真设计和优化，最终仿真设计了一副适用于GSM900MHz／DCS1800MHz通信系统的微带天线。     

Antenna Effective Aperture Measurement With Backscattering Modulation

A scattering measurement method for antenna characterization is described. The antenna backscattering is modulated by an oscillator circuit. The modulation begins, when a known RF power is transferred to the oscillator circuit from the antenna. This enables the measurement of the effective aperture of the antenna, from which the antenna bandwidth and radiation pattern are obtained. A theory for antenna aperture measurement is developed using a simple circuit model for the antenna-oscillator system. A dipole and a PIFA with a reactive input impedance at the application frequency were measured. The antenna aperture was measured to an accuracy of 9%, and the measurements complied with simulated and measured references. The method provides simple and accurate bandwidth and radiation pattern measurements with the reactive load the antenna is designed to work with.     

Compact internal multiband antenna for mobile phone and WLAN standards

A novel internal planar inverted-F antenna (PIFA) suitable for handset terminals is presented. The structure combines shorted parasitic patches, capacitive loads and slots to achieve multiband operation. This compact antenna operates in the GSM, DCS, PCS, UMTS, HIPERLAN/2 and IEEE 802.11a bands within 2.5:1 voltage standing wave ratio (VSWR) and with good efficiency.     

一种小型的手机平面倒F天线

设计了一个可工作在GSM850/DCS1800/PCS1900这3个频段的小型加载寄生单元平面倒F天线。天线在820～903 MHz,1.69～2.12 GHz频率范围内的回波损耗可达到-5 dB以下,在850 MHz,1800 MHz,1 900 MHz频率处天线最大增益的测量值分别为3.08 dB,4.41 dB,3.40 dB,满足移动终端在GSM850/DCS1800/PCS1900这3个频段的使用要求。该天线尺寸小、重量轻,适用于移动通信终端。     

频率可调内置天线在手机中的应用

为手机天线设计了一种新颖的频率可调电路,这种设计考虑到影响手机天线设计的几个因素,例如电子开关的偏置的局限和非线性失真.设计和测试了一款能够在850MHz/1800MHz和900MHz/1900MHz之间切换的四频手机天线.天线装配在一块与手机PCB物理尺寸相当的一块印制电路上.调节的电路包括低通滤波器、隔直电容和一只Pin Diode开关.最终设计的天线在两个频带内具有较高的辐射效率和较低的非线性失真.     

基于微蜂窝基站应用的小型化多频段内置天线

一种应用于微蜂窝基站的覆盖5个频段的新型多频段小型化内置天线被提出。该天线的体积为26×16×25mm3,可以工作于以下无线通信系统:GSM850/GSM900/DCS/PCS/UMTS。将该天线与微蜂窝基站模型安装在一起之后的测试结果和仿真结果都已给出并予以讨论。