多层微带贴片天线单元和阵列设计

该文通过结合经验公式和全波分析法,设计了一种电容补偿双层贴片、四层介质的微带贴片天线单元,该单元天线在频率为995～1125MHz的范围内,在驻波比SWR1.5的情况下,相对阻抗带宽达到12.26％的工程要求。此外,该文给出由该单元天线组成的216天线阵以及天线阵的驻波比的实测结果,最后给出天线阵的各单元排列方式和单元之间的互耦特性曲线的实测结果。     

Broadband proximity fed ring microstrip antenna arrays

Various gap-coupled array configurations of ring microstrip antennas and rectangular slot cut ring microstrip antennas with proximity fed slot cut ring microstrip antenna for larger bandwidth and gain are proposed. The rectangular slot in ring patch reduces its orthogonal TM₀₁ and TM₀₂ mode resonance frequencies and along with TM₁₀ modes of fed and parasitic ring patches, yields broadband response. The gap-coupled configuration with ring patch and slot cut ring patch yields bandwidth of nearly 430 MHz with broadside radiation pattern and peak gain of more than 9 dBi. By gap-coupling ring patches along all the edges of proximity fed pair of slot cut ring patch, a 3 × 3 ring microstrip antenna array is realized. It yields bandwidth of more than 460 MHz with peak gain of more than 10 dBi. To further improve upon the bandwidth, a 3 × 3 array of ring patches in which rectangular slot is first cut on the edges of ring patch which are gap-coupled along x-axis and further cut inside the patches which are gap-coupled along x and diagonal axes, is proposed. Both of these configurations yield bandwidth of more than 500 MHz (>45%) with a peak gain of around 10 dBi.     

A combined full-wave CG-FFT method for rigorous analysis of largemicrostrip antenna arrays

An accurate and efficient technique is presented for the analysis of large microstrip antenna arrays. The technique consists of an amalgamation of a spatially discrete scheme, consisting of the CG-FFT method and the complex discrete image (CDI) technique. The unique feature of this approach is the use of the spatially discrete CG-FFT for analyzing microstrip structures. The aliasing and truncation errors are thoroughly eliminated in this approach. In addition, the grad-div operators are transformed from singular Green's functions to differentiable expansion and testing functions by using Galerkin's procedure, thereby improving the accuracy and the rate of convergence. To show the accuracy and efficiency of this technique, a number of microstrip arrays, including a large microstrip reflectarray, have been studied. It is found that the simulations carried out using this technique are in very good agreement with measurements     

FDTD中微带线激励源设置的新方法

ＦＤＴＤ已广泛应用于微带问题的计算中,本文提出了一种新的微带线馈电激励设置方式,同以往的激励设置方法不同,它不仅能计算Ｇａｕｓｓｉａｎ脉冲激励也能计算正弦波激励,计算过程中,源平面无需切换成吸收边界,场区的划分使反射场自然从总场区分离出来。     

MoM快速全波分析微带天线阵

微带天线及其阵列有着十分广泛的应用,对它们的精确分析也越来越引起人们的重视.首先采用混合位积分方程的MoM在空域建立全波分析模型,然后采用离散复镜像求解空域格林函数,从而提高了计算效率.三角形网格剖分计算目标也使得本文方法更适合分析复杂结构.同时,又将自适应的有理逼近和MoM结合,用于分析微带天线的宽频带特性和单站RCS,计算效率进一步提高.几个典型实例的数值结果表明了本文方法的有效性.     

A compact high gain microstrip antenna for wireless applications

In this article, we describe a novel type of defective ground surface (DGS) microstrip antenna that achieves higher gain, multi resonant frequency with compact size. The proposed antenna consists of a hexagonal shaped patch with small volume. Six triangular slots have been cut on the ground plane, just below the six corners of the hexagonal radiating patch. Antenna is circularly polarized one and it has the measured peak gain of 7.2 dBi. The antenna shows multi frequency behavior and more than 57% compactness compare to the conventional hexagonal patch antenna. The simulated results are confirmed experimentally. The proposed antenna is simple in structure compared with the regular stacked or coplanar parasitic patch antennas. It is highly suitable for wireless communications.     

Reconfigurable dual-band circularly polarized microstrip patch antenna for wireless applications

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.     

Efficient analysis of electromagnetic radiation from microstrip antenna using volume-surface current contunuity method

The Volume-Surface Current Continuity Method (VSCCM) is presented to analyze electromagnetic radiation from microstrip antenna. The microstrip antenna is discretized into small triangular patches on conducting surface and tetrahedral volume cells in dielectric region. The Method of Moments (MoM) is applied to solve the integral equation. An equation contains the restriction relation between the volume and surface current coefficient is derived from the current continuity equation at those parts where the conducting surface is in contact with the dielectric material. A simple equivalent strip model is introduced in the treatment of the feeding probe in VSCCM. The VSCCM can reduce the unknowns required to be solved in MoM, as well as the condition number of the matrix equation. Numerical results are given to validate the accuracy and efficiency of this method.     

Frequency-tunable open-ring microstrip antenna with optimally-positioned varactors for radiated-power in situ measurements

This paper presents a novel frequency-tunable open-ring microstrip antenna for radiated-power measurements in a real environment. In order to elevate the probing up to a few tens of meters, the antenna must have light-weight, narrow-bandwidth, and broad side-beam characteristics. An open-ring microstrip antenna is a good candidate for satisfying these requirements. Varactors are attached to tune the operation frequency, but the conventional position, which is in the vicinity of the ring-opening, shows a much lower gain and poor cross-polarization level. This paper proposes a superior position for the varactors, which is the upper-edge of the left and right sides of the ring. The reflection coefficient (S₁₁) in the simulation and experiment demonstrated that the resonant frequency can be increased by increasing the supply voltage. The proposed tunable antenna can be utilized in the probing apparatus to measure the radiated power.     

用于星载SAR的双频双极化天线

该文设计了共用一个物理孔径的双频双极化的微带天线。天线采用了可折叠的充气式聚酯薄膜介质结构，有较小的介电常数，较大的相对带宽。天线采用孔径耦合馈电方式，对L波段和S波段的馈电线路可各自优化。讨论了此天线的交叉极化特性和阻抗区配，计算了天线的各个参数和天线用于星载SAR时的系统性能指标。     

A decorrelating detector for use with antenna arrays

This paper addresses the problem of synchronous CDMA communications when, due to bandwidth limitations, signature waveforms have relatively large correlations. A receiver which uses the multiple received signals available from an antenna array is proposed and its performance analyzed. This receiver may be interpreted as a multichannel extension of the decorrelating detector and therefore shares its immunity to near-far effects. The receiver uses the discrimination afforded by the antenna array to effectively reduce the correlation between users' transmitted signals thereby avoiding the reduction in performance which occurs in the single channel decorrelator when signature correlations become significant.This work was supported by the National Science Foundation under Grant MIP-9202081. This paper was presented in part at the International Conference on Communications, ICC'94, New Orleans, Louisiana.     

Shorting pin loaded dual-band compact rectangular microstrip antenna

Theoretical and experimental investigations carried out on shorted microstrip patch antenna for dual band operation. The investigations were carried out by varying the shorting-pin position from the edge to the centre of the patch; such an antenna provides a frequency tunability range from 0.88?GHz to 1.08?GHz for first resonance and from 2.20?GHz to 2.59?GHz for second resonance. A frequency ratio of about 2.91 to 2.2 for the two operating frequencies is observed. When the shorting-pin position is close to centre or at the centre of the patch, a single resonant frequency is observed. It is also observed that the resonant frequency of the antenna heavily depends upon the thickness of the substrate, dielectric constant of the substrate and radius of the shorting-pin.     

Higher order mode excitation for high gain microstrip patch antenna

Higher order mode excitation in the microstrip patch has been achieved to alleviate the low gain problem associated with this particular class of antennas. This higher order mode excitation is achieved by geometric modification of the radiating patch. The designed antenna structure is simple in nature, provides easy fabrication and manufacturing while exhibiting high gain characteristic. The proposed antenna has a measured gain of 10.21 dBi at the operating frequency of 16 GHz. The half power beam width is approximately 36° and 34° in the H- and E- planes respectively. The antenna can be used in the different applications related to the Ku band.     

A dual-band multiple-input multiple-output microstrip antenna with metamaterial structure for LTE and WLAN applications

A method to enhance the gain of microstrip dual-band multiple-input multiple-output (MIMO) antenna using partially reflective surface (PRS) layer is introduced and investigated in this paper. The proposed antenna consists of two FR4 substrates. The lower substrate has two radiating patches with parasitic elements that are supplied independently and create the MIMO property of the antenna. The upper substrate which is known as superstrate is arrays of PRS unit cells. The PRS layer printed on either side of a dielectric substrate and causes the antenna gain to increase in both frequency bands. The proposed antenna is appropriate for LTE (2.4–3.1 GHz) and WLAN (5.1–5.8 GHz) applications. The measured values of S₁₁ and S₂₂ parameters of the antenna are less than −10 dB and its FBR and gain are 12.5 dB and 5dBi, respectively. The average half power beam-width (HPBW) is roughly 108^○.     

角馈微带天线的全波分析

利用积分方程法对角馈型微带天线进行了分析,对其中的奇异振荡函数积分,给出了有效的数值积分方法。数值实验证明了该方法的有效性。同时,给出了角馈微带天线的输入阻抗特性,方向图特性和带宽特性。     

STUDY ON THE WIDE-BAND AND HIGH-GAIN MICROSTRIP ANTENNA ELEMENT

A novel three layers microstrip antenna element that has the advantages of wideband and high-gain is proposed. The eigenvalue equation and the frequency characteristic formulas of the input Voltage Stand Wave Ratio ( VSWR ) are obtained by using the spectral domain method and equivalent circuit method, respectively. With the aid of the numerical results, a C-band microstrip antenna element with bandwidth of 16% (VSWR<1.5) or 25% (VSWR<2) and gain of 10.2-11.3 dB is developed, which are much larger than the bandwidth of 5-6% and the gain of 6-7 dB of the common microstrip antenna element.     

A broadband aperture-coupled stacked microstrip antenna with both patches notched and offset

This paper proposes a new approach to further improving the bandwidth of a typical aperture-coupled stacked microstrip antenna by cutting triangular notches in the radiating sides of both radiating patches together with offsetting both patches. An antenna applying this new approach is designed, fabricated, and tested. The experimental antenna could achieve a measured impedance bandwidth of about 37.5% for the Voltage Standing Wave Ratio （VSWR） 〈 2 in X-band.     

串联邻近耦合馈电微带天线阵列的设计

针对高增益、高效率的微带天线需求,将邻近耦合馈电引入串馈微带阵列,提出两种串联谐振微带天线阵列设计。首先研制出1??16元低副瓣串联天线阵列,工作频率35 GHz,测试得到增益为17.3 dBi,带宽4.3%,副瓣电平-17.6 dB。在上述馈电方式中引入U型谐振器及馈电缝隙,提出一种串联邻近耦合馈电的双频正交极化天线阵列,中心频率分别为4.5 GHz和5.0 GHz,两个频带内带宽分别为5.0%和7.8%,隔离良好,中心频率处增益为7.6 dBi和8.2 dBi。这种馈电方式便于组成高效率的大阵列,同时具有良好带宽,在实现多功能共口径阵列中具有独特优势。     

A novel single feed frequency and polarization reconfigurable microstrip patch antenna

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.     

Analysis of Modified Square Sierpinski Gasket fractal microstrip antenna for Wireless communications

In this paper, the slot loaded microstrip antenna has been developed with Sierpinski gasket technique. The proposed Modified Square Sierpinski Gasket (MSSG) fractal antenna involves a square patch utilizing Sierpinski gasket (triangular) structure. Four triangular slots are loaded at each iteration. The structure is then simulated using commercially available Ansoft HFSS simulator. The multi-band operation has been achieved by the proposed antenna at 15.915 GHz, 20.045 GHz, 23.077 GHz, 27.77 GHz frequencies with −20 dB, −25 dB, −22 dB, −28 dB return loss respectively which works well for Ku (12–18 GHz) and K (18–27 GHz) band. The consistent result is obtained after simulation and the validity of fabricated design is checked by the measured result. The designed antenna is an attractive candidate for applications like wireless multi-band communication systems.