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

2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Muhammad Inam Abbasi ◽  
Muhammad Yusof Ismail ◽  
Muhammad Ramlee Kamarudin ◽  
Qammer H. Abbasi
Keyword(s):  
Liquid Crystal ◽  
Frequency Tuning ◽  
Pin Diode ◽  
Scattering Parameter ◽  
Pin Diodes ◽  
Band Frequency ◽  
Dynamic Phase ◽  
Frequency Tunability ◽  
Phase Range ◽  
Reflectarray Antenna

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.

scholarly journals Development of a Pin Diode-Based Beam-Switching Single-Layer Reflectarray Antenna

2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Muhammad Inam Abbasi ◽  
Muhammad Yusof Ismail ◽  
Muhammad Ramlee Kamarudin
Keyword(s):  
Satellite Communication ◽  
Single Layer ◽  
Field Measurements ◽  
Scattering Parameter ◽  
Pin Diodes ◽  
Band Frequency ◽  
Frequency Tunability ◽  
Unit Cells ◽  
Phase Range ◽  
Beam Switching

This paper presents a practical demonstration for the design and development of a switchable planar reflectarray using PIN diodes in the X-band frequency range. Waveguide scattering parameter measurements for the unit cells and far-field measurements of the periodic reflectarrays have been carried out to verify the predicted results. Reflectarray unit cell measurements demonstrated a frequency tunability of 0.36 GHz with a dynamic phase range of 226°. On the other hand, the designed 6 × 6 periodic reflectarray has been shown to achieve beam switching from +6° to −6° with different switching states of PIN diodes. This type of beam switching can be used in satellite communication for specific region coverage.

scholarly journals Resonant Elements for Tunable Reflectarray Antenna Design

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
M. Y. Ismail ◽  
M. Inam
Keyword(s):  
Single Layer ◽  
Scattering Parameter ◽  
Accurate Analysis ◽  
Band Frequency ◽  
Rectangular Patch ◽  
Phase Errors ◽  
X Band ◽  
Phase Range ◽  
Finite Integral ◽  
Reflectarray Antenna

This paper presents an accurate analysis of different configurations of reflectarray resonant elements that can be used for the design of passive and tunable reflectarrays. Reflection loss and bandwidth performances of these reflectarray elements have been analyzed in the X-band frequency range with the Finite Integral Method technique, and the results have been verified by the waveguide scattering parameter measurements. The results demonstrate a reduction in the phase errors offering an increased static linear phase range of 225° which allows to improve the bandwidth performance of single layer reflectarray antenna. Moreover a maximum dynamic phase range of 320° and a volume reduction of 22.15% have been demonstrated for a 10 GHz reflectarray element based on the use of rectangular patch with an embedded circular slot.

Frequency reconfigurable dual-band MIMO antenna using pentagon slot resonator with improved bandwidth

2017 ◽  
Vol 10 (3) ◽  
pp. 383-389
Author(s):  
Deepali Borakhade ◽  
Sanjay Pokle
Keyword(s):  
Multiple Input Multiple Output ◽  
Dual Band ◽  
Pin Diode ◽  
Vehicular Communication ◽  
Pin Diodes ◽  
Band Frequency ◽  
Mimo Antenna ◽  
Slot Line ◽  
Multiple Input ◽  
Input Multiple Output

In this paper, multiple-input–multiple output (MIMO) antenna with dual-band frequency reconfiguration is presented. The proposed antenna consists of two symmetrical pentagon radiating elements. These radiating elements support bands of 1.5 GHz (GPS) and 2.4 GHz (Wi-Fi) frequency. The two PIN diodes are appropriately located on slot line in order to control the current flowing through the radiator. All simulated results are compared and confirmed with measured results. The antenna has VSWR ⩽1.8 and isolation of −28 dB. The advantage of this antenna is that bandwidth is increased by switching of PIN diode in the range from 80 MHz up to maximum 300 MHz. These characteristics demonstrate that proposed antenna is an attractive solution for a multimode application such as GPS, Wi-Fi routers, vehicular communication, etc. where wideband is required.

Tunable Reflectarray Resonant Elements Based on Non-Linear Liquid Crystal Materials

2013 ◽  
Vol 746 ◽  
pp. 357-362 ◽  
Author(s):  
M.Y. Ismail ◽  
M. Hashim Dahri
Keyword(s):  
Liquid Crystal ◽  
Phase Distribution ◽  
Dielectric Anisotropy ◽  
Method Of Moment ◽  
Dynamic Phase ◽  
Non Linear ◽  
Phase Range ◽  
Ring Elements ◽  
Mechanical Movement ◽  
Liquid Crystal Materials

The operation of the radar technology is based on the mechanical movement of the antenna. To overcome the flaw of the mechanical movement an electronically tunable reflectarray antenna based on non-linear properties of Liquid Crystal materials has been introduced. This paper presents a detailed analysis of the tunability performance of different X-band reflectarray resonant elements printed on 1 mm thick grounded Liquid Crystal materials. Dynamic phase range and frequency tunabilty of rectangular, dipole and ring elements have been investigated by using CST computer model. Non-linear material properties have been used to develop an algorithm based on Method of Moment, for dynamic phase distribution of three resonant elements. It has been shown that the ring element offers a maximum dynamic phase range of 248° as compared to dipole and rectangular elements which offer 238° and 160° respectively. Moreover a maximum frequency tunabilty of 796 MHz, 784 MHz and 716 MHz can be achieved for rectangular, dipole and ring elements respectively with a dielectric anisotropy of 0.45. Waveguide simulator measurements of passive reflectarray unit cells demonstrate that rectangular element is observed to offer a minimum reflection loss of 1.6 dB as compared to dipole and ring elements which offer 3.3 dB and 3.6 dB respectively.

A compact omnidirectional to directional frequency reconfigurable antenna for wireless sensor network applications

2021 ◽  
pp. 1-12
Author(s):  
Melvin Chamakalayil Jose ◽  
Radha Sankararajan ◽  
Balakrishnapillai Suseela Sreeja ◽  
Mohammed Gulam Nabi Alsath ◽  
Pratap Kumar
Keyword(s):  
Wireless Sensor Network ◽  
Sensor Network ◽  
Radiation Pattern ◽  
Antenna System ◽  
Wireless Sensor ◽  
Dual Band ◽  
Design Parameters ◽  
Pin Diodes ◽  
Band Frequency ◽  
Directional Radiation

Abstract In the proposed research paper, a novel compact, ultra-wideband electronically switchable dual-band omnidirectional to directional radiation pattern microstrip planar printed rectangular monopole antenna (PRMA) has been presented. The proposed antenna system has an optimum size of 0.26 λ0 × 0.28 λ0. A combination of radiators, reflectors, and two symmetrical grounds does place on the same layer of the rectangular microstrip PRMA. The frequency agility and the radiation pattern from omnidirectional to directional are achieved using two SMD PIN diodes (SMP1340-04LF). The directional radiation patterns with 180° phase shifts are achieved at the C-band frequency spectrum. The parametric study of the proposed antenna system was performed for different design parameters, and the antenna characteristics were analyzed. An antenna prototype is fabricated using the printed circuit board etching method by using RMI UV laser etching and cutting tools. The measurements of the proposed antenna are conducted in an anechoic chamber to validate the simulations. There are three states of operations due to two SMD PIN diodes being used in switching circuits. In state-I, the proposed antenna radiates at 6.185 GHz (5.275–6.6 75 GHz) in the Ф = 270° direction with a gain of 2.1 dBi, whereas in state-II, it radiates at 5.715 GHz (5.05–6.8 GHz) in the Ф = 90° direction with a gain of 2.1 dBi. In state-III, the antenna exhibits the X-band frequency with center frequency at 9.93 GHz (8.845–10.49 GHz), and the omnidirectional pattern offers a gain of 4.1 dBi. The features of the proposed antenna are suitable for high-speed wireless sensor network communication in industries such as chemical reactors in oil and gas and pharmaceuticals. It is also well suited for IoT and 5G-sub-6-GHz applications.

scholarly journals C-Band and X-Band Switchable Frequency-Selective Surface

Electronics ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 476
Author(s):  
Umer Farooq ◽  
Adnan Iftikhar ◽  
Muhammad Farhan Shafique ◽  
Muhammad Saeed Khan ◽  
Adnan Fida ◽  
...  
Keyword(s):  
Bottom Layer ◽  
Frequency Selective Surface ◽  
Transverse Magnetic ◽  
Unit Element ◽  
Angular Stability ◽  
Band Spectrum ◽  
Pin Diode ◽  
Pin Diodes ◽  
X Band ◽  
Frequency Selective

This paper presents a highly compact frequency-selective surface (FSS) that has the potential to switch between the X-band (8 GHz–12 GHz) and C-band (4 GHz–8 GHz) for RF shielding applications. The proposed FSS is composed of a square conducting loop with inward-extended arms loaded with curved extensions. The symmetric geometry allows the RF shield to perform equally for transverse electric (TE), transverse magnetic (TM), and 45° polarizations. The unit cell has a dimension of 0.176 λ0 and has excellent angular stability up to 60°. The resonance mechanism was investigated using equivalent circuit models of the shield. The design of the unit element allowed incorporation of PIN diodes between adjacent elements for switching to a lower C-band spectrum at 6.6 GHz. The biasing network is on the bottom layer of the substrate to avoid effects on the shielding performance. A PIN diode configuration for the switching operation was also proposed. In simulations, the PIN diode model was incorporated to observe the switchable operation. Two prototypes were fabricated, and the switchable operation was demonstrated by etching copper strips on one fabricated prototype between adjacent unit cells (in lieu of PIN diodes) as a proof of the design prototypes. Comparisons among the results confirmed that the design offers high angular stability and excellent performance in both bands.

Breath air measurement using wide-band frequency tuning IR laser photo-acoustic spectroscopy

2016 ◽  
Author(s):  
Yury V. Kistenev ◽  
Alexey V. Borisov ◽  
Dmitry A. Kuzmin ◽  
Anna A. Bulanova ◽  
Andrey A. Boyko ◽  
...  
Keyword(s):  
Frequency Tuning ◽  
Wide Band ◽  
Band Frequency ◽  
Ir Laser ◽  
Acoustic Spectroscopy ◽  
Photo Acoustic Spectroscopy

Reconfigurable Frequency Textile Antenna with Circular Polarization Using Slotted Technique

2015 ◽  
Vol 781 ◽  
pp. 81-84 ◽  
Author(s):  
Shakhirul Mat Salleh ◽  
Muzammil Jusoh ◽  
Abdul Hafiizh Ismail ◽  
Muhammad Ramlee Kamarudin ◽  
Mohamad Imran Ahmad ◽  
...  
Keyword(s):  
Circular Polarization ◽  
Axial Ratio ◽  
Dual Band ◽  
Operating Frequency ◽  
Pin Diode ◽  
Switching Element ◽  
Band Frequency ◽  
Microstrip Patch ◽  
Textile Antenna

This paper presents a reconfigurable frequency microstrip patch textile antenna using slotted technique. The switchable frequency is achieved by implementing three PIN diode switches at the slotted ground of the antenna. It is discovered that the switching element is capable to configure the frequency at six different states of operating frequencies between 1.575 GHz until 2.45 GHz. With certain switches configuration, the antenna is proficient to produce a dual-band frequency of band 1; 1.575 GHz and 2.45 GHz and band 2; 1.588 GHz and 2.36 GHz. Besides, the antenna has successfully perform an axial ratio of less than <3 dB at the GPS operating frequency of 1.575 GHz. A shieldit super is used for the antenna radiator and felt fabric as the antenna substrate. The design and simulated result shows that the presented antenna is potential to be implemented in GPS and Wi-Fi applications.

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