Design and Analysis of Reconfigurable Antenna for Wide Band Applications

The relevance of reconfiguration in a dynamic environment is to improve an antenna’s performance by allowing it to transition between multiple frequencies. In this paper, we designed a reconfigurable patch antenna and fed it by strip line feeding by placing 2 slots to obtain different resonant frequencies. The feature of reconfigurability is attained by using Pin Diodes. In our design, we take a 2 pin diode. The proposed Antenna can operate on different frequencies i.e. 2.88GHz, 5.5GHz, 10.8GHz and 11.1GHz with the efficiency of 90% and more at different conditions of the diodes. This analysis is done by using HFSS Software.

RECONFIGURABLE MONOPOLE ANTENNA DESIGN BASED ON FRACTAL STRUCTURE FOR 5G APPLICATIONS

a reconfigurable antenna design for 5G applications is presented. It is based on monopole antenna and fractal structure. The design structure is consisted of (monopole) feedline, ground plane, L-shape reflector, fractal structure and PIN diodes. The antenna is printed on (25×29×1.6 mm3) FR-4 substrate of εr=4.3 and tanδ =0.001. The antenna shows a resonant frequency at 4.1 GHz with S11=-11.4 dB and Omni-direction pattern of 1.21 dB gain. The L-shaped reflector is used to maintain the radiation pattern in a specific direction. Moreover, the proposed fractal structure is found to operate as a circuit to give another resonant frequency and enhance the antenna performance. Where it is used to give more manipulation in the antenna performance including: frequency resonance and radiation patterns. The PIN-diodes are used to give many cases for more current manipulation. moreover, the authors used RF (50 SMA port) between monopole antenna and right side of ground plane to optimize directing radiation pattern and to eliminate the problems of interference between AC and DC current that produced from using PIN diode. This manipulation leads to change the resonant frequency and radiation pattern to the desired direction.So all parts are printed on a single side of FR4 substrate

Reconfigurable bandstop filter using active frequency selective surface, design and fabrication

In this paper a novel FSS array is proposed, that provides dynamic band-gap in C-band. Inside the band-gap, the FSS acts as a bandstop filter. Outside the band-gap the amplitude of the reflected wave from the FSS array decreases. Therefore, the outside band is very useful in radar cross section (RCS) reduction. In this paper, at first a new FSS unit cell is designed, then in order to achieve the maximum bandwidth (1.2 GHz), dimensions of the cell are optimized. In the next step, the FSS cell is equipped with PIN diodes. Turning the diodes ON or OFF, shifts the resonant frequency of the band-gap electronically. When diodes are OFF, the resonant frequency and −10 dB bandwidth of the FSS are 5.23 and 0.9 GHz respectively. When the diodes turn ON, the resonant frequency shifts to 4.75 GHz over a bandwidth of about 1 GHz. While the band-gap is shifted dynamically, the bandwidth is kept wide, which is the novelty of this paper. In order to validate the design process, an array of active cells consisting of 128 pin diodes was designed, fabricated and then tested. Finally, the simulation and measurement results are compared with each other and a good agreement is observed between them.

A Simple Monopole Antenna with a Switchable Beam for 5G Millimeter-Wave Communication Systems

A simple and compact antenna with a switchable beam for millimeter-wave communication is proposed in this paper. The antenna has a planar structure, and the design evolution is discussed. The beam switching functionality was achieved by incorporating two PIN diodes in the ground plane of the antenna. By switching ON either of the PIN diodes, the inverted L-shaped stub becomes connected to the ground plane and behaves as a cavity, which causes the dispersion of the radiation pattern. Therefore, a wide-angle (±18∘) beam-switching property can be achieved using a simple and low-cost technique, without the necessity to implement additional conventional circuits. The proposed antenna is characterized by a good performance in terms of return loss, bandwidth, measured gain up to 7.95 dB, and radiation efficiency up to 84%, making it a proper candidate for IoT technology and millimeter-wave 5G devices.

Reconfigurable Reflectarray Antenna: A Comparison between Design Using PIN Diodes and Liquid Crystals

This work presents the design and analysis of active reflectarray antennas with slot embedded patch element configurations within an X -band frequency range. Two active reflectarray design technologies have been proposed by digital frequency switching using PIN diodes and analogue frequency tuning using liquid crystal-based substrates. A waveguide simulator has been used to perform scattering parameter measurements in order to practically compare the performance of reflectarray designed based on the two active design technologies. PIN diode-based active reflectarray unit cell design is shown to offer a frequency tunability of 0.36 GHz with a dynamic phase range of 226°. On the other hand, liquid crystal-based design provided slightly lower frequency tunability of 0.20 GHz with a dynamic phase range of 124°. Moreover, the higher reflection loss and slow frequency tuning are demonstrated to be the disadvantages of liquid crystal-based designs as compared to PIN diode-based active reflectarray designs.