Internal antenna with modified monopole type for DVB-H applications

An internal modified monopole antenna for DVB-H band is presented. By extending the feeding line of the modified monopole and locating it over a ground plane, a wideband input impedance of 328 MHz within 6:1 VSWR is achieved. The proposed antenna has an approximately omnidirectional radiation pattern and yields greater than -3 dBi antenna gain covering DVB-H band. These features are suitable for DVB-H applications     

基于Co2-Z铁氧体材料的DVB-H折叠手机天线

采用传统的固相反应法制得了一种低损耗的Z型铁氧体材料（Sr1Ba2-xBixCo2＋xFe24O41,其中x=0,0.15）,基于此材料设计得到一近似全方向辐射模式,在470～702MHz频段平均增益大于-3dB,且在此频段的辐射效率为33.5%～67.3%的小型化天线,该天线完全满足DVB-H（数字视频广播手持终端传输技术）的应用。     

面向车载鲨鱼鳍的宽频MIMO天线设计

为了解决车载通信天线工作频带窄、尺寸大等缺点,文中提出了一款应用于车载鲨鱼鳍外壳的新型小型化、宽带MIMO天线。为了实现天线的宽带特性,充分利用了印制单极子天线易于引入多谐振的特点,首先通过合理的尺寸设计,将单极子天线谐振频率设计至工作频段中;然后,使用缝隙加载技术,增加天线谐振模式数量并改善天线阻抗匹配特性,拓宽了天线带宽并实现了天线的小型化。为了验证天线实际性能,将天线安装于鲨鱼鳍外壳中进行了测试。结果表明,该天线可以覆盖824～5 000 MHz的频段范围,驻波比均小于3,增益最低1.9 d Bi、最高6.2 d B,效率均高于49.5%、最高达89.2%。该天线可满足车载通信系统对天线的宽带化和小型化要求。     

Multiband integrated wideband antenna for bluetooth/WLAN applications

The paper presents an O-shape multiband monopole antenna design (Antenna-I) with different patch orientations; 90-degree (Antenna-II) and 180-degree (Antenna-III). The proposed Antenna-I is a multiband integrated wideband monopole antenna with two integrated bands supporting modern wireless services such as Bluetooth and Wireless Local Area Network (WLAN) in addition to wideband covering upper Ultra-wideband (UWB) frequencies. The first band ranges from 2.05 to 3.05 GHz and second band from 3.65 to 3.92 GHz in the −10 dB impedance bandwidth range. The wideband covers upper frequencies (5.24–10.75 GHz) in the range of Ultra-wideband. Antenna-II resonates at 2.38 GHz (2.11–2.90 GHz) covering Bluetooth band and upper UWB region 5.18–10.86 GHz. The proposed Antenna-III covers 1.96–2.33 GHz and 3.74–10.46 GHz frequency bands. The antenna gain at integrated band is around 2.8 dBi and varies from 4 dBi to 8.03 dBi in the UWB region. The measured fidelity factor is 0.89 for face to face and 0.82 for side by side. Measured results are presented to validate the antenna performances.     

Design of an Ultra‐Wideband Antenna Using a Ring Resonator with a Notch Function

This paper describes an ultra‐wideband (UWB) antenna that uses a ring resonator concept. The proposed antenna can operate in the entire UWB, and the IEEE 802.11a frequency band can be rejected by inserting a notch stub into the ring resonator. The experiment results indicate that the measured impedance bandwidth of the proposed antenna is 17.5 GHz (2.5 GHz to at least 20 GHz). The proposed UWB antenna has omnidirectional radiation patterns with a gain variation of 3 dBi (1 dBi to 4 dBi).     

Earpiece cord antenna for DVB-H reception in wireless terminals

A modified earpiece cord is proposed and evaluated as a wideband antenna for DVB-H reception. By winding the cord into a high-impedance RF choke at one-quarter wavelength distance from the handset connection, a stable wideband input impedance is achieved. Using two-chip components for impedance matching, the complete UHF band can be covered with >35% antenna efficiency. Measured and simulated results are presented with good agreement.     

Low profile wideband antenna with shaped beams for indoor DVB-H applications

A novel low profile wideband antenna for digital video broadcastinghandheld (DVB-H) indoor applications is presented. The antenna can operate in two modes (circular patch antenna mode and microstrip mode), which leads to down-tilted beams when the antenna is mounted on a wall. An antenna prototype with a height of 46 mm has been constructed and tested. The simulated and measured results show that the antenna has VSWRs less than 2.0:1 and shaped radiation beams in the DVB-H band (470?706 MHz).     

Ultra-wideband planar elliptical ring antenna

An elliptical ring antenna fed by a coplanar waveguide line for ultra-wideband applications is presented. The wideband performance is achieved by extending the length of the elliptical ring's major axis. The elliptical ring antenna has a 2:1 VSWR (return loss <10 dB) from 4.6 to 10.3 GHz and has an average gain of 4.48 dBi. The antenna radiation patterns show a stable variation within its operation band. The parameters determining the antenna wideband characteristic are discussed and the measured performance is presented.     

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.     

Analysis and design of wide band Microstrip-line-fed antenna with defected ground structure for Ku band applications

A wide band Microstrip antenna is proposed for Ku band applications with defected ground structure. A circular shape defect is integrated in the ground plane. A novel equivalent circuit model is proposed for Microstrip patch antenna with defected ground structure. Accurate design equations are presented for the wideband Microstrip antenna and theoretical analysis is done for the proposed structure. The proposed antenna has an impedance bandwidth of 56.67% ranging from 9.8 GHz to 17.55 GHz, which covers Ku-band and partially X-band. The antenna shows good radiation characteristics within the entire band, and has a gain ranging from 5 dBi to 12.08 dBi. Minimum isolation between co-polar and cross-polarization level of 20 dB and 15 dB is achieved in H-plane and E-plane respectively. The simulation of the proposed antenna is done on HFSS v.14, and measured results of fabricated antenna are in good agreement with the theoretical and simulated results.     

Wideband Planar Folded Dipole Antenna With Self-balanced Impedance Property

A planar folded dipole antenna that exhibits wideband characteristics is proposed. The antenna has simple planar construction without a ground plane and is easy to be assembled. Parameter values are adjusted in order to obtain wideband properties and compactness by using an electromagnetic simulator based on the method of moments. An experimental result centered at 1.7 GHz for 50 impedance matching shows that the antenna has bandwidth over 55% . The gains of the antenna are almost constant (2 dBi) in this frequency band and the radiation patterns are very similar to those of a normal dipole antenna. It is also shown that the antenna has a self-balanced impedance property in this frequency band.     

Cylindrical ring dielectric loaded horizontally polarized omnidirectional antenna for wideband radiation

A wideband horizontally polarized omnidirectional antenna with a cylindrical ring dielectric (CRD) loaded is proposed. Compared with the conventional alford-structure loop antenna (ASLA), the impedance and radiation pattern bandwidths are broadened by loading a CRD to the ASLA with two wing sections. The designed antenna is fabricated and measured, and good performance has been obtained. The measured reflection coefficient is less than −10 dB over the frequency band 1.63–2.8 GHz, i.e., 52.8%, which can cover 2G/3G/LTE band totally. The gain variation in all directions of horizontal plane is less than 1.4 dB in the whole band. The maximum gain is 1.56dBi throughout the operating band and it appears at 1.66 GHz. It is worth noting that the gain is around 1dBi and almost constant from 1.9 GHz to 2.7 GHz. Besides, the designed antenna has a compact size of 0.55λ × 0.55λ × 0.057λ, λ is for the lowest frequency of the operating band.     

宽带低交叉极化超材料漏波天线的设计

基于基片集成波导结构提出了一种新型双层电磁超材料单元，并验证了其左手特性。将超材料单元应用于漏波天线的设计，所设计的天线由15个双层电磁超材料单元组成。将设计好的天线进行加工测试，测试与仿真结果吻合较好，表明漏波天线的工作频带为7.20~12.70GHz，在工作频带内可实现从后向-78°到前向+80°的连续主波束扫描，天线在工作频带内的测试增益均大于10dBi，峰值增益为15.2dBi，3dB增益带宽达到50.2%。此外，该漏波天线具有很低的交叉极化电平，交叉极化始终比主极化低至少30dB。相比于新近文献报道的同类型超材料漏波天线，所设计的天线具有更加优越的电气性能。     

Passive parasitic UWB antenna capable of switched beam‐forming in the WLAN frequency band using an optimal reactance load algorithm

We propose a switched beam‐forming antenna that satisfies not only ultra‐wideband characteristics but also beam‐forming in the WLAN frequency band using an ultra‐wideband antenna and passive parasitic elements applying a broadband optimal reactance load algorithm. We design a power and phase estimation function and an error correction function by re‐analyzing and normalizing all the components of the parasitic array using control system engineering. The proposed antenna is compared with an antenna with a pin diode and reactance load value, respectively. The pin diode is located between the passive parasitic elements and ground plane. An antenna beam can be formed in eight directions according to the pin diode ON (reflector)/OFF (director) state. The antenna with a reactance load value achieves a better VSWR and gain than the antenna with a pin diode. We confirm that a beam is formed in eight directions owing to the RF switch operation, and the measured peak gain is 7 dBi at 2.45 GHz and 10 dBi at 5.8 GHz.     

Ultra Wideband Co-planer Microstrip Patch Antenna for Wireless Applications

In this paper, a comparative study of co-planar gap coupled rectangular and elliptical microstrip patch antenna is presented. It is analyzed by using circuit theory concept. The proposed antennas show ultra wideband operations which depend on dimensions of the patches, gap between them as well as air gap thickness. It is observed that the performance of gap coupled elliptical patch antenna is better than that of rectangular patch antenna while the area of rectangular and elliptical patches is same. The bandwidth of proposed rectangular patch antenna is found to be 50.7 % with average gain of 6.5 dBi while for elliptical patch antenna the bandwidth and gain further improves up to 57.6 % and 9.5 dBi respectively. The theoretical results are in good agreement with the simulated results obtained from IE3D simulation software.     

CSRR Loaded Tunable L-Strip Fed Circular Microstrip Antenna

A tunable L-strip fed circular microstrip antenna on thick substrate with CSRR in the ground plane has been analysed and investigated. The antenna is analysed using cavity model and circuit theoretic approach for initial design and then simulated on IE3D simulation software. The antenna is made tunable with PIN diode which makes it to work in different configurations. Two diodes were used to implement a double annular slot, one annular slot and one split slot and CSRR in the ground plane. While other configurations of diodes provide bandwidth and radiation pattern diversity, CSRR provides size reduction of upto 13.31 % along with high gain directivity and radiation efficiency. A maximum gain of 8 dBi, directivity 8.3 dBi has been achieved in the respective band of operations. The antenna exhibits wideband along with multiband characteristic.     

Compact Circularly Polarized Antenna with a Capacitive Feed for GPS/GLONASS Applications

This letter presents a novel compact circularly polarized patch antenna for Global Positioning System/Global Navigation Satellite System (GPS/GLONASS) applications. The proposed antenna is composed of a simple square radiating patch fed by a capacitive dual‐feeder to increase the impedance bandwidth and a lumped element hybrid coupler to achieve the broadband characteristic of the axial ratio (AR). The realized antenna dimensions are 28 mm × 28 mm × 4 mm, which is the most compact size among the dual‐band GPS/GLONASS antennas reported to date. The measured results demonstrate that the proposed antenna has a gain of 2.5 dBi to 4.2 dBi and an AR of 0.41 dB to 1.51 dB over the GPS/GLONASS L1 band (1.575 GHz to 1.61 GHz).     

基于超表面的宽带超低剖面折叠透射阵

该文提出了基于超表面的宽带超低剖面折叠透射阵天线设计方法。该天线由两种超表面阵列和一个作为馈源的开口波导构成。其中,下层超表面能够将馈源发射的线极化入射波转换为交叉极化反射波,上层超表面能够实现特定线极化波的全反射和另一种线极化波的全透射。通过合理设计,该天线能够将辐射电磁波来回反射3次并在较宽频带内实现增益提升,同时其剖面高度能够降至传统透射阵的1/4。天线实测和仿真结果吻合良好,表明3 dB增益带宽达到19.6%(9.2～11.2 GHz),且9.6 GHz处峰值增益达21 dBi,峰值口径效率为30%。该文设计方法为实现宽带低剖面阵列天线设计提供了新思路。     

Dual-Band Antenna Array with Reduced Mutual-Coupling for Wearable Wireless Communication Applications

In this paper, dual-band wearable microstrip patch antenna printed on FR4-substrate is designed and fabricated for wearable wireless communications. A star-shaped monopole Ω antenna connected to 50 Ω transmission line, backed by partial ground plane is used. The antenna dimensions are optimized for wideband radiation characteristics. Different types of dielectric substrates are investigated for wideband wearable applications. The proposed antenna printed on jeans textile substrate introduces an impedance matching bandwidth of 7.3 GHz with maximum gain of 5 dBi. The effect of mutual coupling between two parallel patches, two opposite patches and two orthogonal patches on their radiation characteristics are investigated. High isolation is achieved for two orthogonal patches placed away from each other by 0.3λ with a rectangular strip etched between them and cutting in the ground plane. The isolation is below ? 29 dB within the frequency band. The structure achieves impedance matching bandwidth of 1.8 GHz in 1st-band and 4.8 GHz in 2nd-band with maximum gains of 8.5 dBi and 5.3 dBi, respectively. A prototype element is fabricated, measured and the radiation characteristics coincide with the simulated results. The structure is simple, light-weight, and is suitable for WAN applications in the frequency band from 2 GHz to 7 GHz. The effect of human body tissue on the radiation characteristics of the antenna array is investigated. 

     

Four-Element Cylindrical Dielectric Resonator Antenna for Wideband Monopole-Like Radiation

A new four-element cylindrical dielectric resonator (CDR) array is proposed as a wideband low profile monopole-like antenna. Unlike previous investigations, the present antenna is easy to design and excite as it employs the dominant$ HEM_11delta$mode in each CDR. Ansoft's HFSS based design data and experimental results are presented. As much as 29% matching bandwidth$( S_11≪-10 dB)$with monopole-like radiation pattern over the entire band has been achieved with 4 dBi peak gain from a prototype occupying a very compact space measuring$0.6lambda_0$by 0.1$lambda_0$approximately.