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.     

Small microstrip patch antenna

A novel small microstrip patch antenna is presented. The probe-fed circular microstrip patch incorporates a single shorting post which significantly reduces the overall size of the antenna. Experimental and theoretical impedance behaviour and radiation characteristics of the modified patch are given. Very good agreement between experiment and theory was achieved     

Broadband microstrip patch antenna

The characteristics of a rectangular microstrip antenna with an L-shaped probe are investigated. A foam layer with a thickness of around 10% of the wavelength is used as the supporting substrate. An impedance bandwidth of 35% and an average gain of 7.5 dBi can be achieved. The radiation pattern is stable across the passband     

Center-fed microstrip patch antenna

A novel feeding scheme for microstrip patch antennas is presented, which consists of a coaxial probe and shorting pin separated by a narrow slot centrally cut at the radiating patch. The impedance and radiation characteristics of a conventional probe-fed microstrip patch antenna and the proposed microstrip patch antenna are experimentally examined and compared. The effects of the slot length on the antenna operation are also discussed.     

Cylindrical-rectangular microstrip patch antenna for circularpolarization

The circular polarization condition for a rectangular microstrip patch antenna on a thin cylindrical substrate is investigated. The theoretical study is based on the modal-expansion theory, which is valid for the thin-substrate case. Numerical results for the aspect ratio of the cylindrical-rectangular patch, the optimal feed point for minimum voltage standing wave ratio and the 3-dB bandwidth for circularly polarized radiation are analyzed. Effects of the curvature on the circular polarization condition are also discussed     

Wideband dual-polarised microstrip patch antenna

A dual-polarised microstrip antenna capable of achieving a wide bandwidth, a high isolation, low cross-polarisation levels and low backward radiation levels is presented. The H-shaped coupling aperture is used. For wide bandwidth and easy integration with active circuits, it uses the aperture-coupled stacked microstrip square patches. Measured return loss exhibits a bandwidth of over 20.9%, and isolation is better than 36 dB over the bandwidth. Cross-polarisation levels and the front-to-back ratio are better than 22 and 21 dB, respectively     

Stacked H-shaped microstrip patch antenna

A small H-shaped microstrip patch antenna (MPA) with enhanced bandwidth is presented. The H-shaped antenna is first studied by a transmission line model and then is fully analyzed with a MoM code. A stacked patch configuration is proposed to increase the narrow bandwidth, radiation efficiency and directivity. The stacked H-shaped MPA is studied using Chu's fundamental limit for electrically small antennas.     

Triple-stacked microstrip patch antenna for multiband system

A triple-stacked microstrip patch antenna is presented for a multiband system comprising cellular phone, global positioning system and personal communication services. It consists of three microstrip patches, and there is a slot on the middle patch to couple the first patch to the third patch. The measured results are in agreement with the simulated results at the frequencies of interest.     

Compact dualband rectangular microstrip patch antenna for 2.4/5.12-GHz wireless applications

A dual-band antenna is proposed for WLAN and WiMAX frequency bands. Two resonance frequencies are found to be 2.45 and 5.125 GHz and ?10 dB bandwidth of lower and upper resonance frequencies are 4.13 and 8.82 % respectively. It is observed that frequency ratio is more sensitive with the dimensions of L-shaped slot. The frequency ratio of the antenna for a given dimension of L-slot is found to be 2.092 and gain of the antenna is 3.9 dBi for lower resonance whereas 6 dBi at upper resonance. The theoretical results are compared with the reported experimental result as well as simulated results obtained from IE3D simulation software which are in close agreement.     

一种新型星载SAR宽带双极化微带天线研究

提出了一种新型宽带双极化微带天线：天线单元采用层叠结构,下层为正方形辐射贴片,上层为圆形寄生帖片。同时给出了常见的正方形寄生贴片的结构参数,计算结果表明：采用圆形寄生贴片的新型天线与一般的正方形寄生贴片天线相比,在带宽、隔离度和交叉极化电平等性能上均具有优势,尤其是交叉极化特性,优于正方形寄生贴片结构-5dB左右,具有重要的工程应用价值。     

Dual band tunable microstrip patch antenna

A simple design for a dual-band microstrip antenna operating at 3 GHz is presented. The dual band operation is obtained when the antenna is loaded with a cross-line shorted with a ground plane at one end. The frequency separation is found to be sensitive to the position of the cross-line     

Wideband V-slotted diamond-shaped microstrip patch antenna

A new wideband microstrip antenna with V-slotted diamond-shaped patch on a single-layer foam dielectric and probe feed is presented. The broadband design is achieved by the excitation of resonance frequencies of the diamond patch and V-slot. An impedance bandwidth as high as 50% is achieved, where the antenna gain is stable and its variation is within 1 dB.     

Broadband semicircle-fed flower-shaped microstrip patch antenna

A new wideband flower-shaped microstrip antenna patch, semicircle-fed, is investigated. The broadband characteristic is achieved by introducing flower petals at the four sides of a rectangular patch. The proposed antenna is able to achieve an impedance bandwidth of 63% for VSWR less than 2. Using the same excitation mechanism, a comparison between the proposed antenna, a similar-size rectangular-shaped patch antenna and a diamond-shaped patch antenna is given.     

Liquid crystal tunable microstrip patch antenna

A microstrip patch antenna operating in the 5 GHz range and tuned by liquid crystal (LC) is described. The simulated tuning range is 8% while the measurements showed a range of 4%. Losses in the commercially available LC material at these frequencies give rise to antenna efficiencies ranging from 35?40% at best and falling to around 20% when the LC is in the unbiased state.     

Simple tunable dual-band microstrip patch antenna

A novel technique for designing a tunable dual-band microstrip patch antenna is proposed. Dual-band operation is easily achieved by loading a microstrip patch antenna with one varactor diode placed on a small gap between a square patch and a parasitic strip. It is observed from the measured result that the proposed antenna shows a wide tuning range at the two resonant frequencies.     

一种新型V型槽圆极化微带贴片天线

提出了一种基于非对称V型槽加载的探针馈电圆极化单层钻石形微带贴片天线。通过调节V型槽的槽宽、槽长、开槽倾角及馈电点位置可实现微带贴片天线的圆极化辐射。研究了V型槽尺寸对微带贴片天线性能的影响。结果表明:介质厚度为0.051λ_0(λ_0为中心工作波长)时,天线的阻抗带宽大于9%(VSWR≤2),圆极化带宽为3%(AR≤3),最大增益可达6.29 d Bi,最小轴比小于0.5 d B。     

Compact dual-band dual-polarisation microstrip patch antenna

A novel compact, conformal, dual-band, dual-polarisation antenna is presented. This antenna is capable of generating two distinct frequencies with different polarisation and radiation pattern characteristics: a monopolar mode for terrestrial cellular communication and a circularly polarised, upward oriented pattern for satellite mobile communication. Bandwidths of 2 and 4%, respectively, have been obtained in the two modes     

Miniaturised microstrip antenna for MMIC applications

A novel miniaturised quarter wavelength, H-shaped antenna which will find applications in monolithic microwave integrated circuit (MMIC) design is presented. The antenna occupies approximately one tenth of the substrate area of a half wavelength patch antenna. The effect on the resonance frequency, bandwidth and gain of the antenna are reported     

Design of a compact broadband microstrip patch antenna with probe feeding for wireless applications

In this paper the design and development of a compact broadband probe-fed Microstrip patch antenna for bandwidth improvement and antenna size reduction in a single design is proposed. The well-known technique of effective substrate thickness increment is performed to improve the impedance bandwidth, whereas for size reduction the electrical length of the conducting patch has been increased. A compact probe-fed inverted U-shaped microstrip patch antenna with a W-shaped ground plane has been designed and the experimental results are presented.     

Electronically steerable Yagi-Uda microstrip patch antenna array

This paper describes a dual-frequency circularly polarized electronically steerable microstrip patch antenna array suitable for land-mobile communications. Based on a four-element Yagi-Uda (1928) patch antenna, the four antennas forming the array are located radially from a single square reflector patch on a double-sided printed circuit board. The main lobe of the array covers the elevation angles from 20 to 70° with a peak gain of 8.4 dBi at 1.54 GHz and 11.7 dBi at 1.62 GHz. Full azimuthal coverage is possible by electronically switching between the four elements