共查询到20条相似文献,搜索用时 125 毫秒
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提出了一种低剖面极化可重构超表面天线. 天线由三部分组成:3×4金属矩形贴片阵列组成的超表面覆层、缝隙耦合天线和直流偏置控制电路. 电路包括8个PIN二极管开关组成的四对开关(PIN1,PIN2,PIN3和PIN4)和直流偏置线,通过控制上述四对PIN开关的工作状态,天线可以在线极化、左旋圆极化和右旋圆极化三种极化状态之间转换. 对天线样机进行了加工并给出了实测反射系数、实际增益、轴比和归一化辐射方向图,结果表明:天线在不同工作状态下的共享工作频带为4~5.4 GHz,?10 dB阻抗带宽为29.8%;3 dB轴比带宽为8.3%,从4.6~5 GHz;各状态下的实测增益相差不大,其平均增益都大于5 dBi. 仿真结果与实测结果吻合良好. 相似文献
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提出了一种十字形缝隙加载的小型宽带及圆极化微带贴片天线的设计方法。该天线通过在方形贴片上加载一个大尺寸的十字形缝隙实现天线的尺寸缩减,介质基片采用由FR4和空气层组成的层叠结构,在缝隙中嵌入L型枝节,只需通过调整枝节上同轴线馈电点的位置来获得圆极化或宽带阻抗匹配。ANSYS HFSS仿真分析表明,天线的圆极化带宽(AR≤3 dB)为1.7%,阻抗带宽(VSWR≤2)为5.8%,天线在宽带范围内具有稳定的增益,峰值增益为7.8 dB,同时贴片面积缩减了52.3%。改变馈电点的位置可调节两个谐振频率使天线阻抗带宽达到9.4%,比传统的微带贴片天线阻抗带宽提高了114%。 相似文献
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具有二次Koch分形边界的圆极化微带天线 总被引:1,自引:0,他引:1
设计了一种单馈点圆极化微带天线。微带贴片采用二次Koch分形边界的贴片结构,通过底馈方法激励起两个相互正交的简并模实现圆极化;采用CSTMicrowaveStudio@软件进行了仿真,其结果表明,在微带贴片的对角线上适当位置用探针馈电,可以实现圆极化辐射。对具有介质损耗的天线进行了仿真,结果与理想介质的差异较大。设计了一个右旋圆极化微带天线,并进行了测试。该天线工作于1.575GHz;VSWR小于2的阻抗带宽为51MHz;轴比为4dB;增益为3.8dB;贴片尺寸为42.4mm×42.4mm,可以用作GPS天线。 相似文献
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一种双频左/右旋圆极化可重构环形缝隙微带天线 总被引:3,自引:3,他引:0
设计了一种频率比为1.9的双频左/右旋圆极化可重构环形缝隙微带天线,其在高频段和低频段分别工作于线极化和圆极化状态。在该天线中,环形缝隙和相互正交的四个缝隙臂将接地面分为五部分,缝隙臂上跨接两对PIN二极管开关和隔直电容。通过二极管开关的控制,天线在低频频率上可实现左/右旋圆极化的切换,在高频频率上则可保持其线极化性能不变。实验结果表明,天线在1.6 GHz的低频段上具有12.5%的3 dB轴比带宽,在3.06 GHz的高频段上其–10 dB阻抗绝对带宽为100 MHz,成线极化状态,辐射方向图近似不变。 相似文献
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文章根据不停车电子计费系统(ETC)的国家标准(GB/T 20851.1-2007)要求,设计出了一款采用圆形贴片的右旋圆极化微带贴片天线,并对其馈电结构进行了传输线等效模型的理论分析。该天线采用十字型缝隙口径耦合馈电方式,结构简单,可作为ETC系统的车载单元(OBU)天线使用。经实验证实,此种类型天线不但易于产生圆极化波,而且可以得到比较理想的阻抗带宽、圆极化带宽和增益等以满足设计要求。 相似文献
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通过对微带贴片天线单元的仿真与优化,得出了法向轴比小于3 dB的右旋圆极化微带贴片天线单元;用所得的天线单元组阵得到9元相控阵天线,仿真得到其S11参数小于–16 dB、增益大于13 dB和轴比小于3 dB。针对微带贴片相控阵天线的轴比特性,提出了降低轴比的几种布阵方法,得到0.2 dB的轴比,最后分析并总结了改善微带贴片相控阵天线轴比的一般方法。 相似文献
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A small reconfigurable patch antenna is proposed to achieve polarization diversity for digital multimedia broadcasting systems at 2.6 GHz. To obtain polarization diversity, a pair of on‐slit PIN diodes is inserted in each diagonal of a cross‐shaped patch. Thus, four PIN‐diodes on these slits are utilized to change the connection of the slits and thus achieve polarization. Bias circuits for the diodes are allocated in the cutting corner of the cross‐shaped patch to minimize the antenna size. The antenna produces left‐hand circular polarization, right‐hand circular polarization, or linear polarization, depending on the PIN‐diode status. Analysis of circular polarization operation is explicated. Measurements show a gain of about 1.5 dB, a cross polarization of about ?20 dB, and an axial ratio of about 2.5 dB. 相似文献
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A novel design of a microstrip patch antenna with switchable slots (PASS) is proposed to achieve circular polarization diversity. Two orthogonal slots are incorporated into the patch and two pin diodes are utilized to switch the slots on and off. By turning the diodes on or off, this antenna can radiate with either right hand circular polarization (RHCP) or left hand circular polarization (LHCP) using the same feeding probe. Experimental results validate this concept. This design demonstrates useful features for wireless communication applications and future planetary missions 相似文献
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A Novel Single-Feed Circular Microstrip Antenna With Reconfigurable Polarization Capability 总被引:2,自引:0,他引:2
Boyon Kim Bo Pan Nikolaou S. Young-Sik Kim Papapolymerou J. Tentzeris M.M. 《Antennas and Propagation, IEEE Transactions on》2008,56(3):630-638
A single-feed circular microstrip antenna with reconfigurable polarization capability is proposed. This antenna has a simple structure, which consists of a radiating circular patch, five switches (PIN diode), three matching stubs, and a 50 microstrip feed line. It can be switched between 4 different states: two states (low-frequency and high-frequency) for linear polarization (LP), one state for left hand circular polarization (LHCP) and one for right hand circular polarization (RHCP) by controlling the bias voltage of two PIN diodes. At the same time, three switchable matching stubs are used for matching every polarization state. Simulation results and experimental results show that the proposed antenna demonstrates a low cross polarization level, good impedance bandwidth, and a very good axial ratio in the circularly polarized states. 相似文献
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A novel reconfigurable microstrip patch antenna with frequency and polarization diversities is proposed. A U‐slot is incorporated into a square patch, and a PIN diode is utilized to switch the slot on and off, which realizes the frequency diversity characteristic. The polarization diversities among linear polarization (LP), right‐hand circular polarization (RHCP), and left‐hand circular polarization (LHCP) are also obtained by switching three PIN diodes on the slot and the truncating corners of a square patch on and off. The antenna design and experimental results are presented. 相似文献
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In this paper, a novel polarization and frequency reconfigurable microstrip patch antenna which can switch between vertical and horizontal linear polarizations, left hand and right hand circular polarizations at two WLAN frequencies is presented. The orthogonal linear polarizations are achieved by a square microstrip patch antenna fed by two ports on adjacent sides. By introducing corner truncated perturbation on opposite corners of right diagonal of a square patch, orthogonal circular polarizations are achieved. By controlling the bias voltage of two PIN diodes loaded at perturbed corners, a single structure can achieve quad polarization states. Furthermore, by superimposing a square ring slot into the corner truncated square patch and incorporating four PIN diodes into the square ring slot, quad polarization are achieved at dual frequencies. Simulated and measured results indicate that the antenna can achieve quad polarization at two WLAN bands (5.15–5.35 GHz) and (5.75–5.85 GHz). The proposed antenna is simple, has low profile and can be scaled easily for other frequencies. 相似文献
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In this paper, a novel single feed frequency and polarization reconfigurable microstrip patch antenna is presented. This antenna mainly comprises of a corner truncated square patch with a rectangular ring slot, eight PIN diodes and six conductive pads. Four PIN diodes are placed symmetrically in the rectangular ring slot to bridge the gap and to switch the frequency between WLAN bands resonating at 5.2G Hz and 5.8G Hz. Four PIN diodes connect the corner truncated square patch to parasitic triangular conductors. PIN diodes are used to switch the polarization between linear, right hand circular and left hand circular at each frequency. When compared to conventional patch, the proposed design provides a size reduction of 12% at 5.2G Hz, and 30% at 5.8G Hz. The simulated reflection coefficient and radiation patterns are presented and compared with the experimental data. This antenna finds applications for modern wireless communication system. 相似文献
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A Fabry‐Pérot cavity (FPC) antenna producing both high‐gain and circularly‐polarized (CP) behavior is proposed. To increase antenna gain and obtain CP characteristics, a superstrate composed of square patches with a pair of truncated corners is placed above the linearly polarized patch antenna with an approximately half‐wavelength distance from the ground plane at the operating frequency. The proposed antenna has the advantages of high gain, a simple design, and an excellent boresight axial ratio over the operating frequency bandwidth. Moreover, used in an FPC antenna, the proposed superstrate converts a linear polarization produced by a patch antenna into a circular polarization. In addition, the cavity antenna produces left‐hand circular‐polarization and right‐hand circular‐polarization when a patch antenna inside the cavity generates x‐direction and y‐direction polarization, respectively. The measured and simulated results verify the performance of the antenna. 相似文献
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A single probe-fed reconfigurable microstrip patch antenna with symmetric cross slots is proposed. By controlling four pin diodes on the patch slots, the proposed antenna has right hand circular polarisation, left hand circular polarisation or linear polarisation. 相似文献
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A reconfigurable microstrip antenna for switchable polarization 总被引:3,自引:0,他引:3
A novel reconfigurable microstrip antenna with switchable polarization sense is proposed. The proposed antenna has a simple structure, consisting of a corner-truncated square radiating patch, four small triangular conductors, and a microstrip line feed. Using independently biased PIN diodes on the patch, it can produce linear polarization, or left- or right-hand circular polarization according to bias voltages. From the measured results, low cross-polarization levels when operated in the linear state and good axial ratios in the circular state are observed. 相似文献
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BelhachatMessaouda BakirMohammed ZhuShouzheng LiuJingao 《电子科学学刊(英文版)》2004,21(5):421-425
A new design of reconfigurable single-feed circular patch microstrip antenna for dual-band circular polarization application is proposed. The dual-band functionality is realized through incorporating cross-slots of equal slot length in the circular patch and utilizing two PIN diodes to switch the slots on or off. A pairs of tuning stubs are used to tune the circular polarization performance. The design process is presented and good results were obtained. 相似文献