scholarly journals A Frequency Agile Semicircular Slot Antenna For Cognitive Radio System

2016 ◽  
Vol 2016 ◽  
pp. 1-11 ◽  
Author(s):  
Rajeev Kumar ◽  
Ritu Vijay
Keyword(s):  
Frequency Tuning ◽  
Ground Plane ◽  
Wide Frequency Range ◽  
Slot Antenna ◽  
Frequency Range ◽  
Gain Bandwidth ◽  
Radio System ◽  
Slot Length ◽  
Tuning Ratio ◽  
Frequency Agile

A frequency agile antenna is proposed with its ground plane having a semicircular shaped slot which is capable of switching the frequency to different bands, one at a time, in the wide frequency range of 5.33 GHz to 9.90 GHz. To achieve frequency agility, switching of six RF PIN diodes which are placed along the slot length is done in various combinations. Frequency tuning ratio of about 1.85 : 1 can be achieved using this design. Results such as return losses, gain, bandwidth, and radiation patterns are presented in this paper.

MULTIBAND CPW-FED SLOT ANTENNA FOR WLAN/WIMAX APPLICATIONS

2015 ◽  
Vol 77 (10) ◽  
Author(s):  
Igbafe Orikumhi ◽  
Mohamad Rijal Hamid ◽  
Ali Nyangwarimam Obadiah
Keyword(s):  
Radiation Pattern ◽  
Return Loss ◽  
Coplanar Waveguide ◽  
Ground Plane ◽  
Slot Antenna ◽  
Frequency Range ◽  
Resonant Frequencies ◽  
Good Agreement

A square slot antenna fed by a coplanar waveguide (CPW) is presented in this paper. The design consist of two pairs of “F” shaped planar strips placed within a square slotted ground. The strips are used to excite multiple resonant frequencies, the strips are connected to the ground plane by means of ideal switches. The proposed antenna has achieved multiple resonant frequencies of 2.4/5.2/5.8 GHz for WLAN and 3.5/5.5 for WiMAX applications. The measured results shows a good agreement with the simulated results in terms of return loss, radiation pattern and gain. The proposed antenna is designed for the frequency range of 2 GHz to 7 GHz which makes it suitable for Bluetooth, WLAN and WiMAX applications. 

scholarly journals Design of Penta-Band Antenna for Concurrent Multiband Single Chain Radio Receiver

2020 ◽  
Vol 8 (5) ◽  
pp. 2587-2590
Keyword(s):  
Printed Circuit Board ◽  
Circuit Board ◽  
Slot Antenna ◽  
Radio Receiver ◽  
Frequency Range ◽  
Single Chain ◽  
Hexahedral Mesh ◽  
Printed Circuit ◽  
Radio Receivers ◽  
Frequency Agile

In this paper, penta-band antenna is presented for concurrent, multiband, and single chain radio receivers. The antenna is manufactured on a 50 × 100 mm FR4 printed circuit board, and is able to provide five concurrent, operating bands covering a frequency range from 2 to 6 GHz. The antenna bandwidth can be increased up to 280 MHz. Using hexahedral mesh the slot antenna design we can achieve more accurate concurrent bands. These five bands are having larger bandwidth than conventional antennas. Using CM-FARAD (Concurrent Multiband Frequency Agile Radio) architecture we design the antenna for achieving concurrent multiband and single chain radio receiver. Using five slots we achieve our five concurrent bands that operate over wide bands which operate at 2.4,3.0,3,7,4.5,5.6 GHz respectively.

scholarly journals BROADBAND MICROWAVE VIVALDI ANTENNA USING COPLANAR FEED LINE

2019 ◽  
pp. 13-19
Author(s):  
Alexander A. Golovkov ◽  
Polina V. Terenteva ◽  
Alexander G. Zhuravlev ◽  
Michail S. Shmyrin ◽  
Nikolay S. Stenyukov
Keyword(s):  
Antenna Arrays ◽  
Dielectric Substrate ◽  
High Gain ◽  
Wide Frequency Range ◽  
Field Structure ◽  
Slot Antenna ◽  
Manufacturing Cost ◽  
Frequency Range ◽  
Coplanar Line ◽  
Vivaldi Antennas

Nowadays Vivaldi antennas are used as directional emitters with matching and balancing device at the input. As a rule, these devices cause additional losses in case of broadband operation. Besides, the use of the device leads to radiator pattern distortions, especially when operating in a wide frequency range. Stringent operating requirements (wide operating temperature, high humidity, salt fog, vibration, etc.), make the choice of proper chip very complicated. The aim of the study is to develop a slot antenna with a 50-ohm port at the input, which would be easy to manufacture and operate, while maintaining high gain in a wide frequency range. As is known, the field structure in the coplanar line is close to the field structure in the slit field close to it. As is known, the field structure in the coplanar line is similar to the field structure in the slot line. Using mathematics for such fields, means of electrodynamic modeling and numerical calculation, a system is developed that consists of two Vivaldi antennas fed by one coplanar line. Thus, the emitter has a close to a circular pattern and low losses in the structure of feeding, matching and balancing, the functions of which are performed by the coplanar line. The results are given for the frequency range of 1-6 GHz. The device as a whole is a dielectric substrate with radiating structure made as double-sided metallization. Finline-based emitters are acceptable to use for operation in higher frequencies. Antenna has low manufacturing cost and it is easy to repeat. Currently the authors are continuing work on the study of the use of such elements as part of antenna arrays.

scholarly journals Design of Tunable Monopole Arm Planar Spiral Antenna for Cognitive Radio

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Rahul Yadav
Keyword(s):  
Cognitive Radio ◽  
Frequency Tuning ◽  
Impedance Matching ◽  
Ground Plane ◽  
Excitation Frequency ◽  
Antenna Design ◽  
Frequency Range ◽  
Spiral Antenna ◽  
Front End ◽  
Quarter Wavelength

This paper presents a spiral antenna design operating in the frequency range of 1–15 GHz having both selective notch bands and wideband response. The main feed arm of spiral antenna is configured as rectangular monopole of width quarter wavelength to achieve impedance matching with standard 50 Ω excitation. Frequency tuning in the design is achieved by placing varactor diode at an appropriate position along the spiral arms and in the ground plane. The design offers a peak gain of 3.4 dB (simulated) and 3 dB (measured). The unique frequency response of antenna makes its suitable to be used for front-end system of cognitive radio for sensing the spectrum in various modes.

scholarly journals Источник терагерцевого излучения в открытое пространство на основе распределенного джозефсоновского перехода

2020 ◽  
Vol 62 (9) ◽  
pp. 1379
Author(s):  
Н.В. Кинев ◽  
К.И. Рудаков ◽  
Л.В. Филиппенко ◽  
В.П. Кошелец ◽  
А.М. Барышев
Keyword(s):  
Open Space ◽  
Frequency Tuning ◽  
Full Range ◽  
Spectral Characteristics ◽  
High Sensitivity ◽  
Slot Antenna ◽  
Frequency Range ◽  
Single Chip ◽  
Russian Science ◽  
Continuous Frequency

A source of terahertz (THz) frequency range based on a long Josephson junction is proposed and studied experimentally. The emission is transmitted to open space using a slot antenna located on a single chip with the oscillator and matched to collecting lens. We fabricated and studied several designs of the emitter developed for frequency ranges of 250 – 410 GHz, 330 – 530 GHz and 390 – 700 GHz with continuous frequency tuning. The spectral characteristics of output emission are studied using a THz spectrometer based on the superconducting receiver with spectral resolution of about 0.1 MHz. The antenna characteristics in full range of operation are studied using a cooled silicon bolometer with high sensitivity. Experimental results match to numerical simulations. The research was supported by the Russian Science Foundation (Project No. 17-79-20343). The fabrication of samples was carried out using the Unique Science Unit (USU #352529), developed within the framework of the state task.

A compact dual band-notched SWB antenna with high bandwidth dimension ratio

2020 ◽  
pp. 1-7
Author(s):  
Aliakbar Dastranj ◽  
Ghazaleh Lari ◽  
Mosayeb Bornapour
Keyword(s):  
Time Domain ◽  
Coplanar Waveguide ◽  
Ground Plane ◽  
Wide Frequency Range ◽  
Dual Band ◽  
Potential Candidate ◽  
Frequency Range ◽  
High Bandwidth ◽  
Dimension Ratio ◽  
Swb Applications

Abstract In this research, a compact dual band-notched (DBN) super-wideband (SWB) coplanar waveguide-fed antenna with high bandwidth (BW) dimension ratio of 7427.4 has been presented. The proposed antenna covers a very wide frequency range from 2.8 to 40 GHz (BW ratio of 14.28:1) with |S11|<−10 dB. The overall antenna size is 20 × 14 × 1.6 mm3 which consists of an FR4 substrate with a dielectric constant of 4.4, a shovel-shaped radiating patch and the symmetric stair-shaped ground plane. The DBN characteristics are achieved by employing a pair of C-shaped and circular slots on its shovel-shaped radiating patch to reject the interferences caused by two WiMAX (3.7–4.7 GHz) and WLAN (5.7–6.4 GHz) bands. The notched frequency bands can be controlled by changing the radii of slots. The SWB property of the antenna is obtained by using a symmetric stair-shaped ground plane and also a shovel-shaped radiating patch. The measured results of the fabricated prototype in frequency-and time-domain are also presented and compared with the numerical results. The results indicate that the antenna has good performance over the entire operating BW (173.8%) which makes it very potential candidate for modern SWB applications.

scholarly journals Square Slot Antenna for Wide Circularly Polarized Bandwidth and Axial Ratio Beamwidth

2021 ◽  
Vol 17 (1) ◽  
pp. 1-11
Author(s):  
Vijay Sharma ◽  
Tejpal Jhajharia
Keyword(s):  
Circular Polarization ◽  
Coplanar Waveguide ◽  
Ground Plane ◽  
Axial Ratio ◽  
Polarization Characteristic ◽  
Slot Antenna ◽  
Impedance Bandwidth ◽  
Frequency Range ◽  
Antenna Structure ◽  
The Right

Abstract The article proposes design investigation and experimental results of a coplanar waveguide (CPW) fed square slot antenna that gives wideband circular polarization. This circular polarization characteristic is achieved by embedding a square shape stub to left bottom corner and an L-shaped strip to the right upper corner of the slot. A high impedance bandwidth of 87.8 % (3.6–9.0 GHz), a wide axial ratio bandwidth of 73.05 % (4.2–9.0 GHz) and wide 3-dB axial ratio beamwidth of 90° in the entire frequency range of interest are achieved with this antenna structure. To improve the 3-dB axial ratio bandwidth, three slots (two horizontal and one vertical) are scratched at the exterior periphery of the ground plane. These perturbation assemblies are accountable to excite orthogonal modes and help increase an axial ratio bandwidth. The designed antenna displays the constant and steady radiation patterns in the complete frequency range of concern. The overall dimension of the presented compact antenna is 0.24λ × 0.24λ × 0.01λ.

scholarly journals A compact slot antenna with improved bandwidth and gain for wireless applications

2018 ◽  
Vol 7 (4) ◽  
pp. 2370
Author(s):  
Aadya Pant ◽  
Swapna Ch ◽  
Manish Bharat
Keyword(s):  
Ground Plane ◽  
Dielectric Substrate ◽  
Slot Antenna ◽  
Frequency Range ◽  
Entire Frequency Range ◽  
Rectangular Slot ◽  
Wireless Applications ◽  
Feed Line ◽  
Bottom Side ◽  
Good Agreement

A wide-slot antenna is investigated to achieve a bandwidth of about 162%. The ground plane includes a rectangular slot with dual SRR and two semicircular defects in the bottom side of the rectangular slot. A fork like feed-line with two parasitic stubs to increase the bandwidth is used to feed the slot. 37*37*0.8 mm3 is the size of the proposed antenna and the dielectric substrate used is FR4. The measured bandwidth ranges from 1.8-17.5 GHz which is approximately 162%. Significant improvement in gain for the frequency range of 1.8-6.1 GHz is observed. The proposed antenna has radiation patterns that are stable and omnidirectional in both E and H planes in all the six frequency points for entire frequency range. The simulated and measured results are in good agreement.  

scholarly journals Low Phase Noise and Wide-Range Class-C VCO Using Auto-Adaptive Bias Technique

Electronics ◽  
2020 ◽  
Vol 9 (8) ◽  
pp. 1290
Author(s):  
Jeong-Yun Lee ◽  
Gwang Sub Kim ◽  
Goo-Han Ko ◽  
Kwang-Il Oh ◽  
Jae Gyeong Park ◽  
...  
Keyword(s):  
Phase Noise ◽  
Tuning Range ◽  
Frequency Tuning ◽  
Wide Frequency Range ◽  
Cmos Process ◽  
Voltage Controlled Oscillator ◽  
Frequency Range ◽  
Wide Range ◽  
Class C ◽  
Low Phase Noise

This paper proposes a new structure of 24-GHz class-C voltage-controlled oscillator (VCO) using an auto-adaptive bias technique. The VCO in this paper uses a digitally controlled circuit to eliminate the possibility of start-up failure that a class-C structure can have and has low phase noise and a wide frequency range. To expand the frequency tuning range, a 3-bit cap-bank is used and a triple-coupled transformer is used as the core inductor. The proposed class-C VCO implements a 65-nm RF CMOS process. It has a phase noise performance of −105 dBc/Hz or less at 1-MHz offset frequency and the output frequency range is from 22.8 GHz to 27.3 GHz, which consumes 8.3–10.6 mW of power. The figure-of-merit with tuning range (FoMT) of this design reached 191.1 dBc/Hz.

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