具有陷波功能的超宽带缝隙天线的设计与研究

提出了一种具有陷波功能与分形调谐支节的新型超宽带缝隙天线.该天线的结构类似于一般的微带缝隙天线,通过采用分形调谐支节引入半波长谐振结构,使得该天线不仅具备了超宽带缝隙天线的优点,还具备灵活可调的陷波功能.通过计算、测量和尺度放大实验,充分考察了天线的频域特性.实验结果表明该天线的工作频带为2.66～10.76 GHz,在4.95～5.85 GHz频段上具有陷波功能,同时具有相对稳定的辐射方向性和近似的全向特性.该研究对设计小型超宽带天线具有一定的价值.     

Double MOS Loaded Circular Microstrip Antenna with Airgap for Mobile Communication

A novel model of a wide frequency range double MOS loaded circular microstrip patch antenna with airgap between ground plane and substrate is proposed. In this structure two metal oxide semiconductor (MOS) devices are loaded on the patch to enhance the operating frequency range of antenna. To investigate the antenna, different parameters such as resonance frequency, input impedance, frequency agility, VSWR, radiation pattern etc. are calculated and simulated. The resonant frequency of proposed 10 mm radius patch is upward shifted from 5.2 to 6.8 GHz using 1 mm airgap and by loading MOS, antenna can be tuned down to 1.27 GHz operating frequency, which leads to compactness and tunability of antenna. Proposed antenna can be tuned between 1.27 and 6.8 GHz frequency of operation which makes the antenna highly suitable for wide frequency range of mobile communication. The proposed double MOS loaded antenna possessed 82.94 % frequency agility. The antenna is worth for GPS, WLAN, UMTS, and WiMAX operations.     

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.     

基于天线测试系统的简易扩频设计及应用

基于通用天线近远场测试系统,给出了系统扩频设计和工程应用的思路,并分别对扩频系统的本振相参、上下变频的一致性进行了论述。实现了Ka频段以下的平面近场、远场天线测量系统的扩频与应用,并给出了8单元EHF频段阵列天线在不同测试系统下的天线测试方向图。测试结果表明,经扩频的测试系统方向图测量数据与毫米波天线测试系统直接测量的结果吻合,说明扩频系统能够满足毫米波天线方向图的测试需求,并具有较高的测试精度,且设计成本较低。同时还具有一定的通用型,对天线的毫米波扩展测试具有较好的工程应用价值。     

射频开关加载的Koch振子天线研究

将射频开关和Koch分形振子天线相结合,设计了一种可工作在多个频段的射频开关加载的Koch振子天线。通过控制射频开关的通断,可使所设计的天线工作在几个不同的频段。所设计的Koch振子天线与普通振子天线相比,其长度有较大幅度的减小。HFSS软件仿真表明所设计的天线在几个不同的频段都具有良好的性能。     

Frequency notched ultra-wideband microstrip slot antenna with fractal tuning stub

A frequency notched ultra-wideband (UWB) microstrip slot antenna with a fractal tuning stub is proposed. The antenna is similar to a conventional microstrip slot antenna, and by introducing a fractal tuning stub, frequency notched function is achieved. The antenna was studied experimentally regarding impedance bandwidth, radiation patterns and gain. The operation bandwidth of the antenna is from 2.66 to 10.76 GHz, in which a frequency notched band from 4.95 to 5.85 GHz was achieved, along with good radiation performance over the entire frequency range.     

一种双频左/右旋圆极化可重构环形缝隙微带天线

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。     

天线隔离度的频率依赖特性

明确地指出了在计算2个不同频系统的天线隔离度时,天线的功率效率和方向图是随频率变化的,一些情况下是需要使用天线在失配区特性的;详细地阐述了一种估算单频段垂直极化偶极子阵列结构的基站天线方向图参数随频率变化的方法;通过计算电磁学仿真对该方法进行了验证;实际测量实验也表明隔离度和天线频率特性是密切相关的。     

基于紧耦合结构的宽带基站天线设计

随着5G移动通信频段的公布,传统基站天线已不足以覆盖其工作频段。文章以紧耦合阵列天线理论为基础,提出了一种基于紧耦合结构的交叉偶极子宽带基站天线。该天线由两对正交的领结状偶极子天线构成,通过两对交叉偶极子之间的耦合效应,有效地展宽了天线的阻抗带宽。同时,通过在天线和金属反射板之间加载电阻型频率选择表面,吸收由反射板引入的谐振反射波,改善天线高频端辐射性能。仿真及测试结果表明:该天线在1.7-3.6 GHz 频率范围内,可以满足基站天线的设计指标,两端口驻波比均小于1.5,两端口之间隔离度大于55 dB,半功率波束宽度满足65°±5°范围,且整个频段内增益均大于8.5 dBi。     

Josephson admittance spectroscopy of log-periodic antenna at the submillimeter wavelength range

Application of Josephson admittance spectroscopy for the spectral analysis of a broad-band log-periodic antenna was demonstrated at the frequency range from 50 to 700 GHz. A real part of the antenna admittance was reconstructed as a function of the frequency, when the antenna was connected to a Josephson junction. Small-scale features were observed on this dependence. They demonstrated a periodicity in the logarithmic frequency scale and were related to the antenna resonances.     

一种具有陷波特性的改进型Vivaldi 超宽带天线

为了提高常规Vivaldi 天线低频段前向辐射增益,避免超宽带天线对某些已有频段的影响,提出了一 种覆盖1. 2 ~14 GHz 的具有陷波特性的高增益超宽带端射天线。该天线通过在辐射贴片两侧加载Y 形缝隙,有利 于天线表面电流向槽线汇聚,使天线的辐射特性明显提高。低频部分(1. 2 ~7. 5 GHz)的增益比原始天线提高最多2 dB,通过使用CSRR 结构,实现了对WLAN 应用频段(5. 125 ~5. 825 GHz)的隔离,使该天线具有陷波特性。最终,对 天线实物进行加工和测试,进一步验证了设计的可靠性。     

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.     

平面火山烟雾形天线的脉冲辐射特性

设计了一种火山烟雾形平面印刷超宽带天线.研究显示其阻抗带宽低频端可达0.8GHz,在加载电阻回路后带宽低频端可扩展至0.5GHz,在1ns宽的高斯微分脉冲激励下,双锥天线作为发射天线,比较了加载电阻和未加载电阻天线的接收波形,由结果可知,加载天线可以进一步减小脉冲信号波形失真。     

A Gunn-Diode Active Leaky-Wave Frequency Scanning Antenna

A frequency tunable active leaky-wave scanning antenna using Gunn-diode voltage control oscillator (VCO) as source is developed. The frequency tuning controlled by changing either the varactor diode dc bias or the Gunn diode dc bias is demonstrated. The measured scanning angle of active antenna is close to 15 degree as the Gunn VCO frequency tuned from 12.58GHz to 12.98GHz. To excite the first higher order mode of the microstrip leaky-wave antenna is fed asymmetrically. The dominant mode excitation has been successfully suppressed by adding a sequence of covered wire in the middle line of the microstrip leaky wave antenna. This is a prototype of frequency scanning antenna using two terminal device, which can be easily scaled up to millimeter wave frequency region.     

A Reconfigurable Stacked Microstrip Patch Antenna for Satellite and Terrestrial Links

A reconfigurable stacked microstrip patch antenna is proposed. The antenna operates at an upper frequency f_u with a broadside pattern, 7.5-dBi right-hand circularly polarized gain, and 15.8% bandwidth. At a lower frequency f_l, the antenna operates as a planar inverted-F antenna (7.3% bandwidth and 3.9-dBi peak gain) with the main beam directed close to the horizon. Switching between the two regimes of operation is achieved using p-i-n diodes. Antenna operation in the upper frequency band is suitable for low-earth-orbit or medium-earth-orbit satellite communications, and in the lower frequency band, the antenna is useful for terrestrial land-mobile or other wireless applications     

一款面向5G微基站的双频双极化电磁偶极子天线的设计与分析

小型化是进行5G微基站天线设计的重要考虑因素,文中设计了一款适用于5G微基站的电磁偶极子天线. 天线由一对正交放置的单极化电磁偶极子、一对交叉放置的渐变式Γ形馈电线、一个圆形寄生贴片和一块正方形反射板组成,工作频段为2.50~3.62 GHz和4.8~5.0 GHz,能够覆盖工信部规定的5G的全部中频段. 在工作频带内,天线的输入回波损耗小于?10 dB;端口隔离度在低频段小于?25 dB,在高频段小于?42 dB;仿真平均增益在高、低频部分分别为5.57 dBi和9.84 dBi. 该天线能够实现双频段和双极化,可以作为小型化微基站天线设计的参考,同时为5G天线的商用化提供参考.     

Magnetically tunable ferrite resonator antenna

An experimental investigation of a novel ferrite resonator antenna has been carried out. The ferrite antenna was subjected to a static magnetic bias field, applied in directions parallel and perpendicular to the antenna length. The effects on the resonance frequency of the antenna when subjected to this bias were investigated. A maximum frequency shift of 8% above (parallel bias) or 8% below (perpendicular bias) the unbiased resonance frequency was achieved     

短路针加载三角形微带贴片天线的研究

短路针加载微带贴片天线具有较低的谐振频率,特别适用于低频便携式通信设备(如手机)中.与短路针加载矩形和圆形贴片天线相比,短路针加载三角形贴片天线具有更低的谐振频率.本文基于腔模理论,利用未加载三角形贴片天线的静态模,提出了短路针加载三角形贴片天线的理论分析方法,给出了天线谐振频率、输入阻抗及反射损耗的计算公式.数值计算与实测结果相吻合,表明这种分析方法是有效的.     

基于阻尼振荡法的甚低频天线阻抗测量

为了准确测量甚低频发射天线在实际工作环境和工作频点上的输入阻抗,本文提出了一种基于RLC阻尼振荡法的阻抗测量方法,并推导了天线阻抗、电容、电感和电阻的测量公式;该测量方法可通过提高测量电压来提高测量信噪比和测量精度;测量系统谐振于被测天线的工作频点或其附近,使甚低频发射天线输入阻抗的测量值更接近天线在实际工况下的真实值.试验表明,本文提出的测量方法简单可行,具有较高的精度和稳定性,可实现甚低频发射天线输入阻抗的现场测量.     

含有寄生单元的倒F天线分析与设计

提出了在普通倒F天线的两侧和底部同时添加寄生单元的改进倒F天线,该天线与普通的倒F天线相比有更宽的带宽.设计了一个工作于中心频率1.2GHz的改进倒F天线.对该天线的电气特性进行了仿真计算,并对天线主要结构参数对谐振频点和阻抗带宽的影响进行了详细分析.该天线相对带宽达到了33%(VSWR<2),约为普通倒F天线阻抗带宽的4倍,有效地展宽了传统倒F天线的工作带宽,在宽带通信系统中有较好的应用前景.