Design of Miniature UWB-Based Antenna by Employing a Tri-Sectional SIR Feeder

A novel ultra-wideband(UWB)-based microstrip antenna is presented in this work by using a slotted patch resonator,a tri-sectional stepped impedance resonator(SIR)feeder,as well as a reduced ground plane.The whole structure was realized on an FR4 substrate.The impact of incorporating several cases of ground planes on the input reflection has been thoroughly investigated under the same tri-sectional SIR feeder and by employing a slotted patch radiator.Since the complete ground plane presents an inadequate frequency response,by reducing the ground plane,the induced UWB responses are apparent while the antenna exhibits higher impedance bandwidth.The impact of both the uniform impedance resonator(UIR)as well as the SIR feeder on the input reflection has also been examined by following the same adopted reduced ground technique and using a slotted patch radiator.As a result,the UIR feeder exhibits a dual-band frequency response,when a wide notched band is incorporated in the range from 4.5–6.5 GHz.The dual-band response of the bi-sectional SIR feeder is still apparent with a narrower notched band in the frequency range from 4–5 GHz.As far as the tri-sectional SIR feeder is concerned,the UWB response is discernible without recording the existence of a notched band.Additionally,the antenna displays a higher impedance bandwidth compared with the previously reported steps.Our proposed antenna configuration is designed with highly compact dimensions and an overall size of 14×27.2 mm2.Moreover,it operates under the impedance bandwidth of 2.86–10.31 GHz that can be leveraged for numerous applications where wireless systems are used.Our approach presents several advantages compared with the other reported UWB-based antennas in the literature,whereas the measured S11 pattern is in good agreement with the simulated one.

A 2.4 GHz Switched Beam Antenna for Indoor Applications Using Angle of Arrival Estimation

This study introduces a new design of planar antenna array for ISM band applications at 2.4 GHz. This prototype is switched beam antenna, namely planar antenna with four meandered slotted triangular elements (PAFMSTE), which is proposed for wireless indoor applications. The Base Station (BS) equipped with this planar antenna is preferred to be at the center position on the room ceiling to cover all sectors of the room. It is designed to use four directional triangular elements arranged to form a square planar antenna array. The PAFMSTE is used to obtain optimal directivity in four directions in azimuth plane with 3 dB beamwidth of 90°at a specific orientation of 30°in elevation plane. Switched parasitic technique is used to enable PAFMSTE to steer a directional beam through four locations by using four PIN diodes switches. The High Frequency Structure Simulator (HFSS) is used as an efficient simulation tool to optimize the performance of the PAFMSTE antenna. The fabrication and measurements of the PAFMSTE antenna are introduced. The proposed antenna enable radio positioning via Angle of Arrival (AOA) information collected from nearby devices. Then, the Cramér-Rao Bound (CRB) is presented for AOA estimation using identically and equally spaced antenna elements. The CRB depends on the directivity, where the maximum values of CRB are 1.35 × 10-3 and 8 × 10-3 at HPBW of 60° and 90°, respectively.