This paper discusses the design and performance of a frequency reconfigurable antenna for Internet of Things (IoT) applications. The antenna is designed to operate on multiple frequency bands and be reconfigurable to adjust to different communication standards and environmental conditions. The antenna design consists of monopole with one PIN diode and 50Ωfeed line. By changing the states of the diode, the antenna can be reconfigured to operate in a dual-band mode and a wideband mode. The performance of the antenna was evaluated through simulation. The antenna demonstrated good impedance matching, acceptable gain, and stable radiation patterns across the different frequency bands. The antenna has compact dimensions of (26×19×1.6) mm3. It covers the frequency range 2.95 GHz -8.2 GHz, while the coverage of the dual- band mode is (2.7-3.8) GHz and (4.57-7.4) GHz. The peak gain is 1.57 dBi for the wideband mode with omnidirectional radiation pattern. On the other hand, the peak gain of the dual-band mode is 0.87 dBi at 3 GHz and 0.47 dBi at 6 GHz with an omnidirectional radiation pattern too.
In this paper, a new compact coplanar antenna used for Radio frequency identification (FID) applications is presented. This antenna is operated at the resonant frequency of 2.45 GHz. The proposed antenna is designed on an epoxy substrate material type (FR-4) with small size of (40 × 28) mm2 in which the dielectric thickness (h) of 1.6 mm, relative permittivity (er) of 4.3 and tangent loss of 0.025. In this design the return loss is less than −10 dB in the frequency interval (2.12 − 2.84) GHz and the minimum value of return loss is -32 dB at resonant frequency. The maximum gain of the proposed antenna is 1.22 dB and the maximum directivity obtained is 2.27 dB. The patch and the ground plane of the proposed antenna are in the same surface. The proposed antenna has a wide bandwidth and omnidirectional radiation pattern with small size. The overall size of the compact antenna is (40 × 28 × 1.635) mm3. The Computer Simulation Technology (CST) microwave studio software is used for simulation and gets layout design.
This paper presents a new design to obtain wide dual-band operation from a coplanar probe feed antenna loaded with two shorted walls. The lower band of proposed antenna has a 10 dB bandwidth of 611 MHz (24.18%) around the center frequency 2527MHz, and the upper band has a bandwidth of 1255 MHz (27.88%) around the center frequency 4501MHz. The obtained bandwidths cover WLANs operations on all bands. The bandwidth of the first operating frequency covers ISM band (2400- 2483.5) MHz, which is required by IEEE 802.11b, g and Bluetooth standards, and the bandwidth of the second operating frequency covers U-NII1 (5150-5350) MHz band, which is required by IEEE 802.11a and HiperLAN2 standards, and also covers U-NII2 (5470-5725) MHz and U-NII3/ISM (5725-5825) MHz bands, which are required by IEEE 802.11a standard. A three dimensional finite-difference time-domain (3-D FDTD) method is employed to analyze the proposed structure and find its performance. The simulated results are compared with the experimental results.