一种结构新型的双频双极化共口径微带天线

介绍了一种结构新型的双频双极化共口径缝隙耦合微带天线,天线工作的中心频率分别为2.1GHz(L波段)和8.6GHz(X波段),在两个工作频率采用了底馈的馈电方式.用时域有限差分法分别对L波段和X波段双极化的微带辐射单元进行了模拟分析,制作了L波段的2×2元即X波段的8×8元阵天线,同时给出了测量结果.     

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。     

Design of a new dual-frequency and dual-polarization microstrip element

A new type of a dual-frequency and dual-linear-polarization multilayer stacked microstrip antenna element is presented. The feeding mechanism of the element is aperture coupling for one polarization and direct feeding for the orthogonal polarization. The microstrip element exhibits a wide band of operation, high isolation between ports, and high radiation efficiency for both polarizations compared to other types of elements. A parametric study was conducted using a commercial software based on a method of moments (MoM) algorithm and is presented. A prototype with dimensions based on the simulations was built and tested. The agreement between the measured and numerical results is good.     

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。     

Single-element rectangular microstrip antenna for dual-frequency operation

The letter describes a single-element rectangular microstrip antenna which can operate simultaneously for two different frequency bands.     

Slot-coupled meandered microstrip antenna for compactdual-frequency operation

By using a meandered rectangular patch and a slot-coupling feed. Compact dual-frequency operation of microstrip antennas is achieved. In this design, the two operating frequencies are mainly controlled by the patch dimensions and the insetting slit length; a large frequency ratio (>2.5) of the two operating frequencies can also be obtained. For fixed dual-frequency operation, an antenna size reduction as large as ~50% has also been obtained using the present proposed design as compared to the case using a regular rectangular patch     

Slot-loaded bow-tie microstrip antenna for dual-frequency operation

By loading a pair of narrow slots close to the radiating edges of a bow-tie microstrip antenna, dual-frequency operation can be obtained using a single probe feed. Various frequency ratios, within the range 2.0-3.0, of the two operating frequencies can be obtained by varying the flare angle of the bow-tie patch. Details of the antenna design and experimental results are presented and discussed     

Gap-coupled microstrip array antenna for wide-band operation

The theoretical and experimental investigations carried out on a gap-coupled microstrip array antenna reveal that there is a significant improvement in VSWR and bandwidth characteristics of the gap-coupled microstrip array antenna as compared with a conventional microstrip array antenna. The input impedance and the resonant frequency of the gap-coupled patch are found to depend heavily on the gap length as well as on the dielectric constant of the substrate material.     

Broadband microstrip antenna element and array

Foam-supported highly efficient microstrip antennas are described. Theoretical and experimental results show that bandwidths up to 15 percent can be obtained at the expense of an increase in the antenna height (to about 0.1 wavelength). The performance of an array of broadband elements fed by a microstrip corporate feed network is also described.     

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。     

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.     

Synthesis method of series-fed microstrip antenna arrays

A method for non-uniformly spaced series-fed rectangular microstrip array synthesis is given. By this approach the problem of patch array design turns out to be slot array synthesis. The resulting equivalent configuration gives the necessary parameters for the microstrip array geometry. Applications on Taylor, Bayliss and shaped-beam patterns show the validity of the method     

Single-feed circularly polarized microstrip ring antenna and arrays

An analysis is presented for a microstrip-feed proximity-coupled ring antenna and a four-element array. Interactions between the embedded microstrip feed and the radiating element(s) are rigorously included. Results demonstrate that circular polarization of both senses can be achieved with a ring antenna with proper design of two inner stubs located at angles of ±45° with respect to the feedline. Theory and experiment demonstrate an axial ratio 3-dB bandwidth of 1% and the voltage standing wave ratio (VSWR) <2 bandwidth of 6.1%. The axial ratio bandwidth is typical for a microstrip antenna with perturbations, while the VSWR bandwidth is larger than for the circular or rectangular patch with perturbations. A mutual coupling study between two elements shows that the axial ratio is less than 2 dB for interelement spacing greater than 0.55λ_eff, while the VSWR <2 for all spacings considered. A comparison between theory and experiment is provided for a 2×2 element array. The benefits of sequentially rotating the antenna elements in an array environment are presented. The axial ratio and VSWR bandwidths are both increased to 6.1% and 18% for a four-element array. A single-element antenna with two orthogonal feeds to provide both senses of polarization is demonstrated. The ring antenna is small (D/λ₀=0.325), the substrate thickness is thin (H/λ₀~0.035), and the microstrip feed produces a completely planar antenna system, which is compatible with microwave and millimeter integrated circuits (MICs), and monolithic microwave integrated circuits (MMICs)     

Aperture coupled microstrip antenna element design

Aperture coupling is investigated as a feed mechanism for microstrip antenna elements. Using modal field expansion, and assuming that coupling is via a magnetic current in the aperture, calculated data on the antenna parameters are obtained. Several samples are manufactured, tested and practical design curves generated at 5.0 and 10 GHz. Good agreement between theory and experiment is obtained. These new results extend the validity of the analysis at high frequencies and will be useful for design and applications involving this type of antenna.<>     

Dual slot-coupled microstrip antenna for dual frequency operation

A new dual slot-coupled circular antenna for dual frequency or dual polarisation operation is proposed. By optimising the placement of the two slots, high isolation between two ports is achieved. Experimentally, an isolation of more than 35 dB is obtained at L-band.<>     

Compact microstrip antenna with dual-frequency operation

The characteristics of a single-feed dual-frequency compact microstrip antenna with a shorting pin are studied experimentally. Besides the compactness of the antenna, this dual-frequency design can provide a high frequency ratio of >3.0 between the two operating frequencies. Typical experimental results of the proposed antenna are presented and discussed     

A study on wideband gap-coupled microstrip antenna arrays

A method for increasing the bandwidth of microstrip antenna arrays by using gap-coupled patches is described. The input impedance properties of gap-coupled patches are analyzed by the use of the spectral dyadic Green's function for a grounded dielectric slab and the moment method. The dependence of different parameters such as s, L and ϵr on the impedance characteristics is investigated. In considering the effect of feed network, the impedance bandwidth for a VSWR<2 of two-element gap-coupled patch array is as large as 2.5 times that of an ordinary array. The radiation patterns over this bandwidth are measured and discussed. All the microstrip antenna arrays are fabricated on a substrate with ϵr=2.86, h=1.5 mm. A comparison of theoretical and experimental results for both input impedance and radiation patterns are given     

Bandwidth limitations of log-periodic microstrip patch antenna arrays

Results are presented for the frequency dependence of the propagation constant of uniform microstrip patch arrays that allow the bandwidth limitations of log-periodic patch arrays to be deduced. It is found that direct coupling of the patch to the feed line limits the log-periodic bandwidth to about a 2:1 frequency range. However, the introduction of series reactance into the equivalent circuit such as by the use of overlaid patches indicate that log-periodic action over a very wide bandwidth is possible which will then be limited by the uniform substrate and production tolerances.     

Aperture coupled to stripline antenna element for integrated antenna arrays

A new stripline-fed aperture coupled antenna element is proposed. An additional slot in a ground plane allows achievement of efficient electromagnetic coupling with the radiating element and good return loss of the antenna fed by a stripline. The described radiating elements can be easily integrated with a feeding network designed in the most commonly used stripline technique when a large antenna array is to be developed.     

一种新型Ku频段宽带高增益双极化微带天线阵列

介绍了一种新型的Ku频段宽带高增益双极化微带贴片单元及96元阵列的设计。设计中单元采用层叠贴片天线结构,提高了单元的带宽和增益,两个极化端口采用分层馈电,其中水平极化端口采用共面馈电,垂直极化端口采用探针背馈。在馈电网络的设计中引入反向馈电技术,降低了交叉极化。仿真与实测结果表明：该阵列增益达到了26 dBi,口径效率约为51%,交叉极化电平小于-30 dB,水平极化端口相对阻抗带宽达11.3%,垂直极化端口相对阻抗带宽达13.7%,两端口隔离度高于40 dB.