scholarly journals A Compact Frequency Reconfigurable Hybrid DRA for LTE/Wimax Applications

2017 ◽  
Vol 2017 ◽  
pp. 1-13 ◽  
Author(s):  
Sajid Aqeel ◽  
M. R. Kamarudin ◽  
Aftab Ahmad Khan ◽  
Jawad Saleem ◽  
Jamal Nasir ◽  
...  

A compact hybrid antenna structure with frequency reconfiguration capabilities is presented in this article. The proposed design employs a combination of a rectangular DR element and a coupling slot on the structure’s ground plane (GP). The slot shifts the fundamental DRA mode by introducing a slow wave effect and its resonant behavior helps to achieve an omnidirectional pattern at low frequencies. The slot is loaded with a series of PIN diode switches whose ON/OFF combinations alter the effective slot length. Slot loading with PIN diodes results in frequency reconfiguration of the proposed structure with a large tuning range of 76.2% (between 1.73 and 3.86 GHz). A parametric analysis was performed to investigate the effects of slot length, width, and position on the reflection coefficients of the proposed structure. A prototype of the proposed design was fabricated and results were measured. The measured results show a close agreement with the simulated ones. The proposed design is suitable for DCS 1800 MHz, PCS 1900 MHZ, UMTS, LTE 2500–2700 MHz, and Wimax 3.5 GHz.

2021 ◽  
Vol 13 (2) ◽  
pp. 33-44
Author(s):  
Yahieal Alnaiemy ◽  
Lajos Nagy

Our design for a novel UWB monopole antenna structure with reconfigurable band notch characteristics based on PIN diodes is presented in this paper. The proposed antenna is comprised of a modified circular patch and a partial ground plane. The band-notch characteristics are achieved by etching a slot on the partial ground plane and inserting three PIN diodes into the slots for adjusting the operating antenna bands. The reconfigurability is achieved by adding three PIN diodes to obtain eight states with UWB, dual and triple operating bands which can be obtained by changing the PIN state from ON to OFF, and vice versa. The proposed design shows a simple biasing process to switch the frequency bands with insignificant gain variation and low radiation efficiency reduction. The reconfigurability of the frequency is accomplished by adjusting the effective slot length through modifying the PIN diodes states at the desired operating bands. The desired operating frequency bands can be obtained by switching the diodes. A systematic parametric study based on a numerical analysis is invoked to verify and refine the proposed performance. The proposed antenna is fabricated on FR-4 substrate with dimensions of 50×60×1 mm3. The proposed antenna performance was tested experimentally and compared to the simulated results from CSTMW based on FIT. Experimental results were in concordance with simulated results. We found that the proposed antenna design had simple geometry and it was easy to control the frequency bands to suit the applications of WiMAX and WiFi systems.


Frequenz ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Karunesh Srivastava ◽  
Gaurav Varshney ◽  
Rajeev Singh

Abstract A compact tunable notch band ultra-wideband (UWB) antenna is implemented. The band notch characteristics have been obtained by placing a square-shaped metallic loop in the upper ground plane connected via PIN diode. The obtained notched frequency bandwidth can be altered by changing the states of the PIN diode. UWB response with narrow-band notch operation is observed when PIN diode is in ON state. When the PIN diode is in OFF state, the bandwidth of the obtained band notch widens by suppressing the first higher-order resonance and thus a narrow dual-band response is obtained. Moreover, the ratio of the frequency of first higher-order to the fundamental mode in the pass-band can be tuned with the different values as 1.584 and 2.20 in the ON and OFF state of the PIN diode, respectively. Furthermore, the antenna structure offers a compact geometry for the operation with the UWB response with band notch characteristics.


Sensors ◽  
2021 ◽  
Vol 21 (11) ◽  
pp. 3897
Author(s):  
Supakit Kawdungta ◽  
Akkarat Boonpoonga ◽  
Chuwong Phongcharoenpanich

In light of the growth in demand for multiband antennas for medical applications, this research proposes a MICS/ISM meander-line microstrip antenna encapsulated in an oblong-shaped pod for use in diagnoses of the gastrointestinal tract. The proposed antenna is operable in the Medical Implant Communication System (MICS) and the Industrial, Scientific and Medical (ISM) bands. The antenna structure consists of a meander-line radiating patch, a flipped-L defected ground plane, and a loading resistor for antenna miniaturization. The MICS/ISM microstrip antenna encapsulated in an oblong-shaped pod was simulated in various lossy-material environments. In addition, the specific absorption rate (SAR) was calculated and compared against the IEEE C95.1 standard. For verification, an antenna prototype was fabricated and experiments carried out in equivalent liquid mixtures, the dielectric constants of which resembled human tissue. The measured impedance bandwidths (|S11| ≤ −10 dB) for the MICS and ISM bands were 398–407 MHz and 2.41–2.48 GHz. The measured antenna gains were −38 dBi and −13 dBi, with a quasi-omnidirectional radiation pattern. The measured SAR was substantially below the maximum safety limits. As a result, the described MICS/ISM microstrip antenna encapsulated in an oblong-shaped pod can be used for real-time gastrointestinal tract diagnosis. The novelty of this work lies in the use of a meander-line microstrip, flipped-L defected ground plane, and loading resistor to miniaturize the antenna and realize the MICS and ISM bands.


Author(s):  
Asmaa Zugari ◽  
Wael Abd Ellatif Ali ◽  
Mohammad Ahmad Salamin ◽  
El Mokhtar Hamham

In this paper, a compact reconfigurable tri-band/quad-band monopole antenna is presented. To achieve the multi-band behavior, two right-angled triangles were etched in a conventional rectangular patch, and a partial ground plane is used. Moreover, the proposed multi-band antenna is printed on a low cost FR4 epoxy with compact dimensions of 0.23[Formula: see text], where [Formula: see text] is calculated at the lowest resonance frequency. To provide frequency agility, a metal strip which acts as PIN diode was embedded in the frame of the modified patch. The tri-band/quad-band antenna performance in terms of reflection coefficient, radiation patterns, peak gain and efficiency was studied. The measured results are consistent with the simulated results for both cases. The simple structure and the compact size of the proposed antenna could make it a good candidate for multi-band wireless applications.


2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Reza Karimian ◽  
Hamed Tadayon

A new microstrip slot antenna with parasitic elements has been presented in this paper. The proposed antenna is composed of a microstrip feed line, a ground plane on which some simple slots are etched, and parasitic elements. Simulation results show that the antenna structure allows for the independent adjustment of each frequency. A two-element array configuration of this antenna for MIMO application is investigated as well. For comparison between simulation and measurement result both single and array configurations have been fabricated. The measurement result exhibits good radiation performance in terms of return loss, low mutual coupling, and compactness.


2005 ◽  
Vol 41 (15) ◽  
pp. 855 ◽  
Author(s):  
A.B. Yu ◽  
A.Q. Liu ◽  
Q.X. Zhang

2013 ◽  
Vol 427-429 ◽  
pp. 1293-1296
Author(s):  
Yan Zhong Yu ◽  
Ji Zhen Ni ◽  
Xian Hui Li

A printed inverted-F antenna for RFID tag at 5.8 GHz is designed in this paper. The antenna structure consists of an inverted-F patch, a substrate layer, and a ground plane. To reduce costs, the FR4 is selected as the material of substrate layer, which is used commonly in PCB (Printed Circuit Board). Its relative permittivity is 4.4 and a loss tangent is 0.02. The inverted-F patch and ground plane are laid on/under the substrate layer respectively. The designed antenna is modeled, simulated and optimized by using HFSS (high frequency electromagnetic simulation software). Simulation results demonstrate that the printed inverted-F antenna can satisfy the requirements of RFID Tag applications.


2009 ◽  
Vol 421-422 ◽  
pp. 153-156
Author(s):  
K. Sudheendran ◽  
K.C. James Raju

Cubic pyrochlore bismuth zinc niobate thin films are known to exhibit voltage dependent dielectric properties. In this paper, we are demonstrating the fabrication and characterization of interdigital (IDC) and circular patch (CPC) capacitors using the pulsed laser deposited Bi1.5Zn1.0Nb1.5O7 (BZN) thin films on sapphire and platinised silicon substrates respectively. The IDCs fabricated are having 12 fingers of width 12 m each and separated by a gap of 8 m. The CPC are having circular patches with inner radius of 100 m and concentric ground plane with a radius of 300m. The electrical properties of these capacitors were characterized both at low frequencies and at microwave frequencies. The CPC varactors were having a tunability of 25% at 15 Volts. The calculated capacitance of the IDC varactor at 5.3 GHz with 0 V dc bias was 1.1 pF, which has got changed to 0.99 pF by the application of 30 Volts exhibiting a tunability of 10%.


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