Circularly polarised microstrip antenna array using proximitycoupled feed

A 2×2 circularly polarised (CP) microstrip antenna array using a proximity coupled feed and sequential rotation is described. As compared with a previously presented single-element circularly polarised microstrip antenna with a cross-slot, the new array achieves a much wider impedance bandwidth of 11.18% and has an axial ratio bandwidth of 4.1%. The return loss, radiation patterns and axial ratio of the antenna array were measured and are presented     

Single feed wideband circular polarised patch antenna

Based on the air gap and stacked patch configuration, a new wideband circular polarised patch antenna is proposed. Significantly increased impedance and axial ratio bandwidths can be achieved without increasing implementation complexity compared with that of existing patch antennas.     

Circularly polarised conical beam radial line slot antenna

A radial line slot antenna radiating a circularly polarised conical beam is proposed. It is advantageous in the construction of a feeding structure comparing with conventional antennas. Guidelines for the design of the slot arrangement are presented. The experimental results, which are in good agreement with the design, demonstrate the conical beam radiation     

Circularly polarised reflectarray with linearly polarised feed

A design procedure for a circularly polarised (CP) reflectarray with linearly polarised feed is presented. It is validated by simulation and experiment results that exhibit the cross-polar level of -20 dB at the designed frequency, and -10 dB in 14% bandwidth. This type of CP reflectarray can be used as a good substitution for those with a CP feed.     

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     

Circularly polarised printed antenna with conical beam

A new circularly polarised printed antenna concept with conical beam is presented. The proposed concept describes a simple printed structure with an omnidirectional pattern and maximum gain of ~6 dBi at elevation angles between 30° and 60°, with features suitable for various commercial applications. The voltage standing wave ratio is <1.3 and the axial ratio is <2 dB in the 3% operational bandwidth around 4.6 GHz. The experimental results show good agreement with those obtained by simulation     

Circularly polarised equilateral-triangular microstrip antenna withtruncated tip

A novel circular polarisation (CP) design of a single-feed equilateral-triangular microstrip antenna with a truncated tip is proposed and experimentally studied. It is found that, when the side length of the truncated tip is ~0.09 times that of the triangular patch, circularly polarised radiation can be achieved by using a single probe feed. Details of the antenna design are described, and experimental results of the CP performance are presented and analysed     

Circularly polarised antenna with switchable polarisation sense

The authors present the design of a wideband circularly polarised antenna with switchable polarisation sense. The basic antenna is a circularly polarised aperture coupled patch antenna with a slot excitation located along the diagonal of a rectangular patch. A second slot is added along the other diagonal and beam-lead pin diodes are inserted in both slots to allow a dual sense operation for a compact structure in a 4% CP bandwidth     

Circularly polarised dielectric resonator antenna with metallicstrip

A new design of circularly polarised slot fed dielectric resonator antenna (DRA) is presented. The dissymmetry of the design enabling circular polarisation relies on a metallic strip printed on top of the resonator. Simulations are compared with measurements for a single antenna as well as a four DRA sequential rotation array     

Wideband single-fed circularly polarised patch antenna

A novel circularly polarised (CP), single-fed microstrip antenna is presented. The antenna consists of a stacked structure of almost square patches. The proposed design has a reduced antenna size compared to the conventional CP microstrip antenna at a given operating frequency. The impedance and axial ratio bandwidths are large and CP radiation quality is excellent over the entire upper hemisphere. The proposed antenna is suitable for global positioning system (GPS) applications.     

Circularly polarised microstrip antenna with a tuning stub

A simple circular polarisation (CP) design of microstrip antennas using a tuning stub is proposed and studied. It is also demonstrated that, by applying this CP design method to a circular microstrip patch with a cross slot having equal slot lengths, a compact circularly-polarised microstrip antenna can easily be implemented, with much more relaxed manufacturing tolerances as compared to the case of using a cross slot of unequal slot lengths. Details of the antenna designs are described, and experimental results are presented and discussed     

Circularly polarised printed antenna fed by coplanar waveguide

A new structure of the circularly polarised printed antenna fed by coplanar waveguide (CPW) is proposed. FDTD analysis predicts the radiation of the circularly polarised wave from the antenna. The validity of this analysis is established by comparing with experimental results     

Small circularly polarised folded patch antenna

A small circularly polarised (CP) patch antenna with dual T-shaped probe feeds is presented. The patch is folded like a cap to generate a CP wave as well as to reduce the size of the antenna. The proposed antenna is operated at the centre frequency of 2.28 GHz with circular polarisation. The impedance bandwidth (SWR<2) is 21.8% from 2 to 2.49 GHz and the axial ratio bandwidth (AR<3 dB) is 3.5%. The measured gain is around 7.5 dBi. The antenna shows a good CP performance with a symmetric radiation pattern. The total area of reduction is 54% in comparison with the conventional half-wave patch antenna.     

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。     

Circularly polarised planar antenna excited by coplanar waveguide feedline

A circular patch antenna fed by a coplanar waveguide (CPW) line is proposed to obtain circular polarisation (CP). The CP results from the combined excitation of the patch by an inclined slot (integrated in the CPW feedline) and the CPW feedline termination. The asymmetrical characteristics of the excitation involve the excitation of both the odd and the even modes in the CPW line.     

CPW feed circularly polarised microstrip antenna using asymmetric coupling slot

Design of a coplanar waveguide (CPW) feed square microstrip antenna with circular polarisation (CP) radiation is described. This CP design is achieved by using an asymmetric inductively coupling slot in the ground plane of the CPW feed line. Results show that the proposed antenna can have a CP bandwidth of 2.4%, whereas a simple inclined coupling slot case has 1.6% CP bandwidth at a fixed square patch size. Typical experimental results are presented and discussed     

Circularly polarised truncated-corner square patch microstriprectenna for wireless power transmission

A circularly polarised rectenna using a truncated-corner square-patch microstrip antenna has been developed for wireless power transmission at 5.8 GHz. The gain and axial ratio achieved were 8.5 dBi and 0.5 dB at 5.82 GHz respectively. A GaAs Schottky barrier diode was employed for microwave to DC conversion with a maximum conversion efficiency of 60%     

Microstrip patch array antenna

A microstrip array with mutual coupled rectangular patch radiators is described. By the avoidance of a corporate feeding network, advantages in the antenna performance and design are realisable. Experimental results are presented for both linearly and circularly polarised antennas which demonstrate the usefulness of this special antenna configuration.     

Low-cost monopulse antenna using bi-directionally-fed microstrip patch array

A new technique for realising a simple low-cost monopulse antenna using a symmetrical bi-directionally-fed microstrip patch array is described. The antenna is designed and demonstrated at Ka-band. Two squinted beams are radiated from a bi-directionally fed microstrip patch array, and a sum/difference pattern is synthesised using the in-phase and out-of-phase signals achieved using a hybrid ring coupler. The measured return loss is better than 10 dB at the sum and difference port, and the depth at broadside is more than 30 dB.