Circularly polarised aperture coupled microstrip antenna

The orthogonal mode of an aperture coupled rectangular microstrip antenna can be coupled to the aperture-excited mode with coplanar microstrip lines to provide a compact circularly polarised element with a single aperture feed. An equivalent circuit model was developed for the analysis and design of this element, and a working version was used to demonstrate the concept. The features of this antenna are compared with several other circularly polarised microstrip antennas     

Analysis of an aperture coupled microstrip antenna

A microstrip patch antenna that is coupled to a microstripline by an aperture in the intervening ground plane is analyzed. Coupled integral equations are formulated by using the Green's functions for grounded dielectric slabs so that the analysis includes all coupling effects and the radiation and surface wave effects of both substrates. A Galerkin moment method solution of the coupled integral equations agrees quite well with measured data. Design data are contained in parameter studies, many of which are verified by experimental results.     

Transmission line analysis of nonlinear slot coupled microstrip antenna

The transmission line method is used for the analysis of microstrip antennas fed by several nonlinear slots with 'H' shapes or new geometries. This analysis allows the input impedance of nonlinear slot coupled microstrip antennas to be calculated for the four different structures.<>     

Flat lens antenna concept using aperture coupled microstrip patches

A planar lens antenna based on aperture coupled microstrip patch elements with stripline delay lines is described. Features of this design are discussed, and results for transmission coefficient magnitude against frequency are presented. The background for the development of this lens configuration is discussed in terms of a natural progression from frequency selective surfaces, and the inadequacies of simpler geometries are explained     

Wideband and high-gain one-patch microstrip antenna coupled withH-shaped aperture

The design, fabrication, and experimental implementation of the one-patch microstrip antenna coupled with an H-shaped aperture are presented. The presented antenna has a wide bandwidth, high gain, and low cross-polarisation levels with only one-patch. The measured bandwidth of this antenna is 56.2% for the voltage standing wave ratio ⩽2.0. The cross-polarisation level is below -18.2 dB at the E-plane and below -25.7 dB at the H-plane. The maximum gain at 2.05 GHz is 10.4 dBi and the 3 dB gain bandwidth with a centre frequency at 2.17 GHz is 24%     

新型带扇形馈源的宽带缝隙天线

介绍了一种新型的采用扇形微带馈源的宽带缝隙天线,给出了反射损失曲线和辐射方向图。该天线采用稍高的相对介电常数（εr=4．3）和薄基片（h=1．1mm）,获得了约106％的阻抗带宽（S11≤-10dB）,频率范围是1．65GHz～5．38GHz。采用电磁仿真软件Ansoft HFSS8．0^TM对几个天线尺寸的影响进行了仿真与讨论,并与文献[6]的结果相比较,验证了设计的有效性,同时也证明了结果的可靠性。     

Characterisation of aperture coupled microstrip patch antenna withthick ground plane

The feasibility of using a thick ground plane with an aperture coupled microstrip patch antenna while maintaining reasonable antenna performance is demonstrated using moment method and reciprocity analyses in the spectral domain. The thick ground plane, which may serve as a heatsink for active MMIC circuitry, or as a mechanical support for thin substrates, is particularly advantageous in millimetre wave phased array applications. It is found that the effect of ground plane thickness is to reduce the level of coupling from the feed line to the patch     

A planar broad-band flared microstrip slot antenna

Experimental results have been obtained on a planar multioctave bandwidth flared microstrip slot. When crossed, the element is capable of horizontal, vertical, or circular polarization. A design was fabricated and measurements were taken to define the performance. The input impedance and radiation characteristics are shown to have a broadband response when configured as a cavity-backed element.     

A dual polarized aperture coupled circular patch antenna using a C-shaped coupling slot

The design and development of a dual linearly polarized aperture coupled circular microstrip patch antenna at C-band are presented. The antenna uses a novel configuration of symmetric and asymmetric coupling slots. Variations in isolation between orthogonal feedlines and antenna axial ratio with the position of coupling slots are studied and broadband isolation and axial ratio are achieved. The prototype antenna yields 7.6 dBi peak gain, 70/spl deg/ 3-dB beam width, 25 dB cross-polarization levels and an isolation better than 28 dB between the two ports. With an external quadrature hybrid coupler connected to the two orthogonal feedlines, the antenna yields 3-dB axial ratio bandwidth of more than 30% at 5.8 GHz.     

Design of aperture coupled microstrip antenna array fed bydielectric image line

A novel design for a linear array of microstrip antennas, aperture coupled to a dielectric image line has been developed. The design is based on a simplified theory to determine the impedances of the antennas at their apertures, and in turn, the coupling to each antenna from the image line. The theory developed is verified using an eight-element linear array and the experiment results are very good     

A twin slot antenna on a layered substrate coupled to a microstrip feed line

A method is described for calculating the input impedance as seen by the detector for a twin slot antenna structure. This technique is then used to analyze several twin slot antenna configurations, leading to improved performance.     

双极化微带缝隙天线单元研究

研究了一种S波段双极化十字缝隙天线单元,利用电磁仿真软件仿真分析了缝隙宽度对驻波和交叉极化性能的影响。仿真结果表明,天线的驻波和方向图特性较好,增大缝宽展宽驻波带宽但没有明显提高天线的交叉极化电平。测试结果与仿真结果基本吻合。     

C-shaped slot loaded reconfigurable microstrip antenna

A new electronically reconfigurable dual frequency microstrip patch antenna with highly simplified varactor tuning circuitry is presented. The proposed design allows relatively independent selection of the two operating frequencies. Tuning ranges of 7.1 and 4.1% are realised for the two resonant frequencies without the use of any matching circuits.     

Analysis of a slot microstrip antenna

The slot microstrip antenna is used as a folded slot dipole symmetrically fed across a gap by means of a strip line. A theoretical model equivalent to several lossy transmission lines had been described previously to explain the bandwidth and the radiation admittance. The theory is improved when coupling between the two equivalent radiating lines of every slot is taken into account, and explains a fourth resonance near the third one, which had been measured on several models. Theoretical results and experiments are in good agreement. They are radiation admittance in a wide frequency band, current distribution along each slot and radiation patterns.     

Investigation of wide-band microstrip slot antenna

This paper presents the simulation and experimental investigations of a printed microstrip slot antenna. It is a quarter wavelength monopole slot cut in the finite ground plane edge, and fed electromagnetically by a microstrip transmission line. It provides a wide impedance bandwidth adjustable by variation of its parameters, such as the relative permittivity and thickness of the substrate, width, and location of the slot in the ground plane, and feed and ground plane dimensions. The ground plane is small, 50 mm/spl times/80 mm, and is about the size of a typical PC wireless card. At the center frequency of 3.00 GHz, its width of 50 mm is about /spl lambda//2 and influences the slot impedance and bandwidth significantly. An impedance bandwidth (S/sub 11/=-10 dB) of up to about 60% is achieved by individually optimizing its parameters. The simulation results are confirmed experimentally. A dual complementary slot antenna configuration is also investigated for the polarization diversity.     

一种H型缝隙和L型探针耦合双极化微带天线的设计

设计了一种宽带、低交叉极化、高隔离度的双极化微带天线结构,采用L型探针耦合和H型缝隙耦合两种方式相结合,结构简单.天线设计频率为2.4 GHz,两端口-10 dB阻抗带宽达到26.7%和30%,隔离度在整个带宽内低于-32 dB、交叉极化电平在60°方位角内低于-24 dB、在主瓣内低于-32 dB,理论仿真和实验测试结果吻合较好.     

Small dual-frequency microstrip antenna with cross slot

A new design of single-feed, reduced-size dual-frequency rectangular microstrip antenna with a cross slot of equal length is presented. The frequency ratio of the two operating frequencies is mainly determined by the aspect ratio of the rectangular patch, and the reduction in the two operating frequencies is achieved by cutting a cross slot in the microstrip patch. Details of the experimental results for such a design are presented and discussed     

An aperture coupled microstrip antenna with a proximity feed on a perpendicular substrate

A new feeding configuration for microstrip antennas is described, where separate substrates are used for the radiating patch element and the microstrip feedline. The substrates are joined perpendicular to each other, and the patch is excited through an aperture in the antenna substrate ground plane by proximity coupling to the microstrip feedline, This design thus has a number of advantages over other feeding configurations, particularly when used in an integrated phased array application. These features, as well as the measured results from two experimental models, are described.     

Single-feed dual-frequency rectangular microstrip antenna withsquare slot

By cutting a square slot at the centre of a rectangular microstrip patch, both compactness and dual-frequency operation can be achieved. Several designs have been implemented. From the experimental results obtained, the required antenna size using the proposed design method can be reduced by ~17% compared to that of the conventional design method using a simple patch without the slot. Typical experimental results are presented and discussed     

Broadband triangular microstrip antenna with U-shaped slot

The broadband design of a triangular microstrip antenna with a U-shaped slot is demonstrated. With a foam substrate of thickness ~0.08 λ₀, a slotted triangular microstrip antenna with an operating bandwidth of ~18% is obtained, which is ~1.8 times that of a corresponding simple triangular patch antenna. Details of the antenna design and experimental results are presented