scholarly journals Broadband metasurfaces loaded with non-Foster elements

2021 ◽  
Vol 2015 (1) ◽  
pp. 012061
Author(s):  
Nikita Kalmykov ◽  
Bair Buiantuev ◽  
Dmitry Kholodnyak
Keyword(s):  
Frequency Band ◽  
Conversion Error ◽  
Magnetic Conductor ◽  
Bandwidth Extension ◽  
Artificial Magnetic Conductor ◽  
Low Profile ◽  
Low Profile Antennas ◽  
Unit Cells ◽  
Operational Frequency ◽  
Impedance Converter

Abstract Metasurfaces have been widely used to design low-profile antennas, thin absorbers, lenses etc. The operational frequency band of a metasurface is rather narrow due to its resonant nature. Loading metasurface unit cells with non-Foster elements allows for remarkable bandwidth extension. In this paper, design of a broadband metasurface to operate as an artificial magnetic conductor is considered. The main issues which influence the bandwidth extension such as implementation of the non-Foster load, minimization of conversion error of a negative impedance converter, and circuit stabilization are addressed.

scholarly journals A Compact, Low-Profile Log-Periodic Meandered Dipole Array Antenna with an Artificial Magnetic Conductor

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Oh Heon Kwon ◽  
Sungwoo Lee ◽  
Jong Min Lee ◽  
Keum Cheol Hwang
Keyword(s):  
Ground Plane ◽  
Array Antenna ◽  
Main Beam ◽  
Beam Direction ◽  
Magnetic Conductor ◽  
Artificial Magnetic Conductor ◽  
Line Configuration ◽  
Low Profile ◽  
Unit Cells ◽  
Meander Line

A compact and low-profile log-periodic meandered dipole array (LPMDA) antenna with an artificial magnetic conductor (AMC) is proposed. For compactness, a meander line configuration is implemented with dipole elements and optimized using a genetic algorithm (GA) to realize the LPMDA antenna. As a result, a size reduction of approximately 30% is achieved as compared to a conventional log-periodic dipole array antenna. To enhance the gain characteristics, the AMC ground plane configuration is realized with 9 × 9 unit cells for the LPMDA antenna. Two prototypes of the proposed LPMDA antennas with and without an AMC are fabricated and measured to verify its performance. The measured −10 dB reflection ratio bandwidths are 2.56 : 1 (0.85–2.18 GHz) and 2.34 : 1 (0.92–2.16 GHz) for the proposed LPMDA antennas with and without the AMC, respectively. The gain at the main beam direction within the operating frequency bandwidth is significantly improved from 3.94–7.17 dBi to 7.86–10.01 dBi by applying the AMC.

scholarly journals Applications of AMC-based impedance surfaces

2018 ◽  
Vol 5 ◽  
pp. 3 ◽  
Author(s):  
Constantine A. Balanis ◽  
Mikal Askarian Amiri ◽  
Anuj Y. Modi ◽  
Sivaseetharaman Pandi ◽  
Craig R. Birtcher
Keyword(s):  
Anechoic Chamber ◽  
State University ◽  
Arizona State University ◽  
Leaky Wave ◽  
Magnetic Conductor ◽  
Artificial Magnetic Conductor ◽  
Full Wave ◽  
Low Profile ◽  
Low Profile Antennas ◽  
Good Agreement

The recent and major enhancements of artificial magnetic conductor (AMC) and their applications namely RCS reduction, low-profile antennas and holographic leaky wave antennas are reviewed. Full-wave simulations are compared to measurements of fabricated models, and a good agreement is attained. All of the measurement were conducted in the Arizona State University electromagnetic anechoic chamber (EMAC).

scholarly journals A Dual-Band High-Gain Subwavelength Cavity Antenna with Artificial Magnetic Conductor Metamaterial Microstructures

Micromachines ◽  
2021 ◽  
Vol 13 (1) ◽  
pp. 58
Author(s):  
Guang Lu ◽  
Fabao Yan ◽  
Kaiyuan Zhang ◽  
Yunpeng Zhao ◽  
Lei Zhang ◽  
...  
Keyword(s):  
Printed Circuit Board ◽  
High Gain ◽  
Resonant Wavelength ◽  
Circuit Board ◽  
Dual Band ◽  
Dual Frequency ◽  
Magnetic Conductor ◽  
Artificial Magnetic Conductor ◽  
Low Profile ◽  
Unit Cells

This paper presents dual-band high-gain subwavelength cavity antennas with artificial magnetic conductor (AMC) metamaterial microstructures. We developed an AMC metamaterial plate that can be equivalent to mu-negative metamaterials (MNMs) at two frequencies using periodic microstructure unit cells. A cavity antenna was constructed using the dual-band AMC metamaterial plate as the covering layer and utilizing a feed patch antenna with slot loading as the radiation source. The antenna was fabricated with a printed circuit board (PCB) process and measured in an anechoic chamber. The |S11| of the antenna was −26.8 dB and −23.2 dB at 3.75 GHz and 5.66 GHz, respectively, and the realized gain was 15.2 dBi and 18.8 dBi at two resonant frequencies. The thickness of the cavity, a sub-wavelength thickness cavity, was 15 mm, less than one fifth of the long resonant wavelength and less than one third of the short resonant wavelength. This new antenna has the advantages of low profile, light weight, dual-frequency capability, high gain, and easy processing.

scholarly journals A Low-Profile HF Meandered Dipole Antenna with a Ferrite-Loaded Artificial Magnetic Conductor

2021 ◽  
Vol 11 (5) ◽  
pp. 2237
Author(s):  
Oh Heon Kwon ◽  
Won Bin Park ◽  
Juho Yun ◽  
Hong Jun Lim ◽  
Keum Cheol Hwang
Keyword(s):  
High Frequency ◽  
Dipole Antenna ◽  
Unit Cell ◽  
Operating Frequency ◽  
High Permeability ◽  
Magnetic Conductor ◽  
Artificial Magnetic Conductor ◽  
Low Profile ◽  
Compact Size ◽  
Binary Genetic Algorithm

In this paper, a low-profile HF (high-frequency) meandered dipole antenna with a ferrite-loaded artificial magnetic conductor (AMC) is proposed. To operate in the HF band while retaining a compact size, ferrite with high permeability is applied to the unit cell of the AMC. The operating frequency bandwidth of the designed unit cell of the AMC is 1.89:1 (19–36 MHz). Thereafter, a meandered dipole antenna is designed by implementing a binary genetic algorithm and is combined with the AMC. The overall size of the designed antenna is 0.06×0.06×0.002 λ3 at the lowest operating frequency. The proposed dipole antenna with a ferrite-loaded AMC is fabricated and measured. The measured VSWR bandwidth (<3) covers 20–30 MHz on the HF band. To confirm the performance of the antenna, a reference monopole antenna which operates on the HF band was selected, and the measured receiving power is compared with the result of the proposed antenna with the AMC.

scholarly journals Low-Profile Spidron Fractal Dipole Antenna with a Ferrite-Loaded Artificial Magnetic Conductor for Manpack Applications

2020 ◽  
Vol 10 (24) ◽  
pp. 8843
Author(s):  
Oh Heon Kwon ◽  
Keum Cheol Hwang
Keyword(s):  
High Frequency ◽  
Dipole Antenna ◽  
Magnetic Conductor ◽  
Very High Frequency ◽  
Artificial Magnetic Conductor ◽  
Received Power ◽  
Low Profile ◽  
Profile Characteristics ◽  
Very High ◽  
Good Agreement

In this paper, a Spidron fractal dipole antenna with a ferrite-loaded artificial magnetic conductor (AMC) is presented. By applying ferrite composed of nickel–zinc with a high permeability value, a compact AMC that operates in the broadband frequency range within the high-frequency/very-high-frequency/ultra-high-frequency (HF/VHF/UHF) bands was designed. A Spidron fractal-shaped dipole antenna with a quasi-self-complementary structure was designed and combined with a miniaturized ferrite-loaded AMC. This allowed the designed AMC-integrated dipole antenna to operate in a wide frequency band, covering the HF/VHF/UHF bands, with low-profile characteristics. A prototype of the proposed Spidron fractal dipole antenna with the AMC was manufactured and measured and found to meet low VSWR (voltage standing wave radios) specifications of <3.5 within the 20–500 MHz bandwidth range. The simulated and measured results are in good agreement. The size of the Spidron fractal dipole antenna with the AMC is 0.03×0.026×0.001λ3 relative to the wavelength of the lowest operating frequency. The received power of the Spidron fractal dipole antenna with the AMC was also measured when it was applied to relatively small applications, such as a manpack in this case.

scholarly journals A Low-Profile High-Gain and Wideband Log-Periodic Meandered Dipole Array Antenna with a Cascaded Multi-Section Artificial Magnetic Conductor Structure

Sensors ◽  
2019 ◽  
Vol 19 (20) ◽  
pp. 4404 ◽  
Author(s):  
Son Trinh-Van ◽  
Oh Heon Kwon ◽  
Euntae Jung ◽  
Jinwoo Park ◽  
Byunggil Yu ◽  
...  
Keyword(s):  
High Gain ◽  
Operating Frequency ◽  
Main Beam ◽  
Impedance Bandwidth ◽  
Beam Direction ◽  
Magnetic Conductor ◽  
Artificial Magnetic Conductor ◽  
Low Profile ◽  
Operating Bandwidth ◽  
Meander Line

This paper presents a low-profile log-periodic meandered dipole array (LPMDA) antenna with wideband and high gain characteristics. The antenna consists of 14 dipole elements. For compactness, a meander line structure is applied to each dipole element to reduce its physical length. As a result, a compact and wideband LPMDA antenna is realized, exhibiting a wide impedance bandwidth of 1.04–5.22 GHz (ratio bandwidth of 5.02:1) for | S 11| < −10 dB. To enhance the antenna gain performance while maintaining the wideband behavior, the LPMDA antenna is integrated with a new design of an artificial magnetic conductor (AMC) structure. The designed AMC is realized by combining three AMC structures of different sizes to form a cascaded multi-section AMC structure, of which its overall operating bandwidth can continuously cover the entire impedance bandwidth of the LPMDA antenna. The proposed AMC-backed LPMDA antenna is experimentally verified and its measured −10 dB reflection bandwidth is found to be in the range of 0.84–5.15 GHz (6.13:1). At the main beam direction within the operating frequency bandwidth, the gain of the proposed AMC-backed LPMDA antenna ranges from 7.15–11.43 dBi, which is approximately 4 dBi higher than that of an LPMDA antenna without an AMC. Moreover, the proposed antenna has a low profile of only 0.138 λ L. ( λ L is the free-space wavelength at the lowest operating frequency).

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