Helix Inspired 28 GHz Broadband Antenna with End-Fire Radiation Pattern

This paper presents the design and characterization of a via free planar single turn helix for 28 GHz broadband applications.The proposed antenna is designed using ROGERS RO4003 material,having a simple structure and end-fire radiation pattern.The antenna comprises of a compact dimension of 1.36λ_(0)×0.9λ_(0) with a thickness of 0.0189λ_(0)(whereλ_(0) is the free-space wavelength at the central frequency of 28 GHz).Parametric study has been carried out to investigate the impact of key design parameters and to achieve an optimum design.Results show a good agreement between the simulated and measured results.A single turn helical inspired antenna covers−10 dB impedance bandwidth of 26.25-30.14 GHz having a peak gain of 5.83 dB and radiation efficiency up to 85%.Moreover,linear array configurations with 2 and 4 elements have been analyzed for applications with higher gain and space constraints.Presented array configurations are suitable for applications having space constraints in one dimension.Results show that peak gain up to 8.2 dB and 11.1 dB can be achieved with 2 and 4 elements,respectively.Due to its simple planar and via free structure,this antenna is suitable for 5G communications and for sensing,imaging,IoT and tracking applications at 28 GHz band spectrum.

A Frequency Selective Surface Loaded UWB Antenna for High Gain Applications

This paper presents the design of wideband and high gainFrequency Selective Surface(FSS)loaded antenna for ultra-wideband(UWB)wireless applications requiring high-gain.The antenna consists of a monopole and an FSS reflector.Initially,a conventional rectangular monopole antenna is modified using slot and stub to achieve wide operational bandwidth and size reduction.This modified antenna shows 50%miniaturization compared to a primary rectangular monopole,having a wide impedance bandwidth of 3.6-11.8 GHz.Afterward,an FSS is constructed by the combination of circular and square ring structures.The FSS array consisting of 8×8-unit cells are integrated with the antenna as a reflector to enhance the performance of the proposed miniaturized UWB antenna.The loading of FSS results in an improvement of at least 4 dBi gain in the entire operational bandwidth.Moreover,the antenna’s bandwidth is also increased at the lower frequency band due to the presence of the FSS.A prototype of the antenna is fabricated and tested to verify the simulation results.The simulation and measurement results show that the antenna offers a wideband-10 dB impedance bandwidth ranging from 2.55-13GHz with a stable peak gain of 8.6 dBi and retains the radiation pattern stability.