Design of a low‐cost broadband loaded dipole antenna for VHF/UHF frequency range

2019 ◽  
Vol 13 (12) ◽  
pp. 1983-1988 ◽  
Author(s):  
Mohammad Bod ◽  
Mehdi Ahmadi‐Boroujeni ◽  
Karim Mohammadpour‐Aghdam
2018 ◽  
Vol 7 (1) ◽  
pp. 73-78
Author(s):  
S. Patil ◽  
P. Petkov ◽  
B. Bonev

Every electronics equipment must deal with EMC test. The testing laboratory of electronics equipment for radiation emission must have accurate calibrated antennas. The field strength of total radiated radio frequency is average of all incident signals at given point, this incident spinals originates from various directions. In order to measure three components of all electric field vectors, a tripole antenna is most beneficial over conventional antenna because of it responds to signal coming from multi directions. This paper presents novel three axis wide band calculable rod-dipole antenna with hybrid balun for the range of 900MHz to 3.2GHz frequencies, the proposed antenna is small in size and good electrical characteristics, the Important parameters measured and verified with designed values. Return loss S11 more than -10dB within the frequency range 900MHz to 3.2GHz. The result of this articles are evident that, efficient construction of antenna with low cost, light weight module applicable for EMC pre-compliance test at open field site.


2018 ◽  
Vol 7 (2.7) ◽  
pp. 952
Author(s):  
V Teju ◽  
P V. P. S Nikhil ◽  
A Pranusha ◽  
Ch Divya ◽  
G Bhanuprakash

This paper proposes single element of micro-stripe antenna having wider bandwidth and also its arrays which are implemented for wire-less applications. In contemplation of wide frequency range of operation, antenna is fed with integrated balun. The single element antenna works under frequency range of 34GHz to 46GHz where reflection loss is less than -10dB and the obtained gain is 2.1 dBi. The linear 8-element array of antenna has been implemented and to obtain low mutual coupling between the elements of antenna a rectangular stub has been implemented. By enforcing the array methodology the not only the overall gain of the antenna has increased but also results in wider scanning angle.  


2021 ◽  
Vol 21 (4) ◽  
pp. 291-298
Author(s):  
Chandana SaiRam ◽  
Damera Vakula ◽  
Mada Chakravarthy

In this paper, a novel compact broadband antenna at UHF frequencies is presented with canonical shapes. Hemispherical, conical and cylindrical shapes have all been considered for antenna configuration. The designed antenna provides an instantaneous frequency range from 370 to 5,000 MHz with omnidirectional characteristics. The antenna was simulated in CST Microwave Studio, fabricated and evaluated; the results are presented. The simulated and measurement results are in good agreement. The antenna has voltage standing wave ratio (VSWR) ≤ 1.9:1 in 400–570 MHz, 2,530–3,740 MHz and 4,180–4,620 MHz; it has VSWR ≤ 3:1 over the operating frequency range 370–5,000 MHz and the measured gain varies from -0.6 to 4.5 dBi over the frequency band. The concept of canonical-shaped antenna elements and the incorporation of triple sleeves resulted in a reduction of the length of the antenna by 62% compared to the length of a half-wave dipole antenna designed at the lowest frequency. The antenna can be used for trans-receiving applications in wireless communication.


Author(s):  
Mesud Kahriman ◽  
Ozlem Coskun ◽  
Esin Yavuz

In recent years humans are more exposed to human-made fields than natural fields with developing technologies. Especially, widespread of wireless communication technologies in all areas of daily life and getting closer to sensitive organs like brain caused an increase in possible risks and worries about human health. In the study, a temperature measurement card has been designed and produced with the aim of observing the temperature rise at the phantom model generated by EM energy source. To that end, we present a study on the temperature rise of small dipole antenna (2450 MHz) that operate close to a user’s head (1, 4 and 7 cm). We found good correspondence between the temperature rise values evaluated in the phantom heads. According to the results of measure, expected temperature rise in the tissue exposed to RF energy may varies to the distance between radiated source and tissue.


Electronics ◽  
2018 ◽  
Vol 7 (10) ◽  
pp. 236 ◽  
Author(s):  
Wonseok Choe ◽  
Jinho Jeong

A waveguide-to-microstrip transition is an essential component for packaging integrated circuits (ICs) in rectangular waveguides, especially at millimeter-wave and terahertz (THz) frequencies. At THz frequencies, the on-chip transitions, which are monolithically integrated in ICs are preferred to off-chip transitions, as the former can eliminate the wire-bonding process, which can cause severe impedance mismatch and additional insertion loss of the transitions. Therefore, on-chip transitions can allow the production of low cost and repeatable THz modules. However, on-chip transitions show limited performance in insertion loss and bandwidth, more seriously, this is an in-band resonance issue. These problems are mainly caused by the substrate used in the THz ICs, such as an indium phosphide (InP), which exhibits a high dielectric constant, high dielectric loss, and high thickness, compared with the size of THz waveguides. In this work, we propose a broadband THz on-chip transition using a dipole antenna with an integrated balun in the InP substrate. The transition is designed using three-dimensional electromagnetic (EM) simulations based on the equivalent circuit model. We show that in-band resonances can be induced within the InP substrate and also prove that backside vias can effectively eliminate these resonances. Measurement of the fabricated on-chip transition in 250 nm InP heterojunction bipolar transistor (HBT) technology, shows wideband impedance match and low insertion loss at H-band frequencies (220–320 GHz), without in-band resonances, due to the properly placed backside vias.


Frequenz ◽  
2019 ◽  
Vol 73 (11-12) ◽  
pp. 355-366
Author(s):  
Martin Frank ◽  
Benedict Scheiner ◽  
Fabian Lurz ◽  
Robert Weigel ◽  
Alexander Koelpin

Abstract This paper presents the design and characterization of linearly polarized low-cost transmitarray antennas with ± 70° azimuth beamforming range in V-band in order to add beam steering functionality to existing radar front ends. The transmitarray antennas are composed of 13 × 13 planar unit-cells. The unit-cells consist of two layers of RO4350B laminate and provide a one bit phase resolution. The desired unit-cell behavior has been validated by simulations and measurements. Eight transmitarrays with different phase distributions have been designed and fabricated to realize different beam steering angles in azimuth. The experimental characterization of the radiation patterns shows the desired performance in the frequency range from 59 GHz to 63 GHz. Additionally, steering angle combinations in azimuth and elevation up to 40° have been realized and successfully demonstrate by measuring the 2D radiation pattern.


Author(s):  
Zhuochen Wang ◽  
Sibo Li ◽  
Ruibin Liu ◽  
Xuecang Geng ◽  
Xiaoning Jiang

Ultrasound imaging with high resolution and large field of depth has been increasingly adopted in medical diagnosis, surgery guidance and treatment assessment because of its relatively low cost, non-invasive and capability of real-time imaging. There is always a tradeoff between the resolution and depth of field in ultrasound imaging. Conventional ultrasound works at a particular frequency, with −6 dB fractional bandwidth of < 100%, limiting the resolution or field of depth in many ultrasound imaging cases. In this paper, a bi-frequency co-linear array covering a frequency range of 5 MHz-20 MHz was investigated to meet the requirements of resolution and depth of field for a broad range of ultrasound imaging applications. As a demonstration, a 31-element bi-frequency co-linear array was designed and fabricated, followed by element characterization and real time sectorial scan (S-scan) phantom imaging using a Verasonics system.


2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Botao Feng ◽  
Weijun Hong ◽  
Shufang Li ◽  
Wenxing An ◽  
Sixing Yin

A novel dual-wideband double-layer magnetoelectric dipole unidirectional antenna with a modified horned reflector for 2G/3G/LTE applications is proposed. Firstly, a double-layer electric dipole structure is presented to provide a dualwideband, whose folded lower layer mainly serves the lower frequency band while the inclined upper layer works for the upper frequency band. In addition, to reduce the size of the antenna and improve impedance matching, a new feeding structure designed with inverted U-shaped and tapered line is introduced. Finally, a modified horn-shaped reflector, instead of a ground plane, is employed to achieve stable and high gains. The antenna prototype can achieve a bandwidth of 24.4% (790 MHz–1010 MHz) with a stable gain of 7.2 ± 0.6 dBi for the lower band, and a bandwidth of 67.3% (1.38 GHz–2.78 GHz) with a gain of 7.5 ± 0.8 dBi for the upper band covering all the frequency bands for 2G/3G/LTE systems. To the best of our knowledge, it is the first double-layer magnetoelectric dipole antenna proposed. Compared with the existing ME dipole antennas, the proposed antenna, which is completely made of copper, can be easily fabricated at low cost and thus is practicable for 2G/3G/LTE applications.


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