scholarly journals Design and Characterization of VHF Band Small Antenna Using CRLH Transmission Line and Non-Foster Matching Circuit

2020 ◽  
Vol 10 (18) ◽  
pp. 6366
Author(s):  
Soyeong Lee ◽  
Jonghyup Lee ◽  
Seongro Choi ◽  
Yong-Hyeok Lee ◽  
Jae-Young Chung ◽  
...  
Keyword(s):  
Transmission Line ◽  
Spiral Inductor ◽  
Potential Candidate ◽  
Very High Frequency ◽  
Electrically Small Antenna ◽  
Left Handed ◽  
Received Power ◽  
Low Profile ◽  
Power Enhancement ◽  
Small Antenna

In this paper, we propose an electrically small antenna consisting of a composite right/left-handed (CRLH) transmission line (TL) and a non-Foster matching circuit. An interdigital capacitor (IDC) and spiral inductor are used to fabricate the very high frequency (VHF) band antenna based on CRLH TL. The size of the proposed antenna is as small as 0.025 × 0.014 × 0.0008 λ at 145.5 MHz using the zeroth-order resonant generated by the CRLH TL. The antenna operation bandwidth is extended by the non-Foster circuit (NFC) consisting of a pair of transistors in a cross-coupled manner. An antenna prototype is fabricated and the input impedance, the received power, and gain of the proposed antenna are measured. The results show that the broadband characteristic is maintained while the form factor is extremely small compared to the wavelength. The average received power enhancement and increased bandwidth of antenna are 17.3 dB and 335.5 MHz (from 249.2–268.2 to 145.5–500 MHz), respectively. The calculated gain of the proposed antenna with the non-Foster is about −45 dBi at 155 MHz. The proposed antenna can be considered as a potential candidate of a low-profile antenna for military ground communications at the VHF band.

An Efficient, Wideband, CPW-Fed Antenna Based on Simplified Composite Right/Left-Handed Transmission Line

Frequenz ◽  
2017 ◽  
Vol 71 (1-2) ◽  
pp. 37-40
Author(s):  
Zhaozhan Li ◽  
Cheng Zhou ◽  
Yanhong Lin
Keyword(s):  
Transmission Line ◽  
Resonance Frequency ◽  
Dispersion Analysis ◽  
Order Mode ◽  
Electrically Small Antenna ◽  
Left Handed ◽  
Resonance Frequencies ◽  
Unit Cells ◽  
In Series ◽  
Small Antenna

Abstract A wideband electrically small antenna (ESA) based on simplified composite right/left-handed transmission line (SCRLH-TL) is designed, fabricated and tested. The antenna consists of two different sized SCRLH-TL unit cells with different+1st-order mode resonance frequencies. The wideband property of antenna is achieved when these two+1st-order mode resonance frequency suitably merge. A dispersion analysis of the SCRLH-TL reveals that an increase in series of the dual-spiral capacitor would decrease the+1st-order mode resonance frequency, thus reducing the electrical size of the proposed antenna. The 10 dB fractional bandwidth (FBW10 dB) was 54.5 % and the measured maximum was 96.2 %, with an electrical size of 0.32λ0×0.16λ0×0.015λ0 at 3.0 GHz (where λ0 is the wavelength in vacuum). It is shown that the numerical results closely fit the measured results.

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.

Low-profile folded-monopole antenna with unbalanced composite right-∕left-handed transmission line

2012 ◽  
Vol 48 (14) ◽  
pp. 813 ◽  
Author(s):  
J.Q. Gong ◽  
J.B. Jiang ◽  
C.H. Liang
Keyword(s):  
Transmission Line ◽  
Monopole Antenna ◽  
Left Handed ◽  
Low Profile

scholarly journals 2.45 GHz high-gain electrically small antenna with composite right/left-handed ladder structure

2012 ◽  
Vol 48 (16) ◽  
pp. 971-972 ◽  
Author(s):  
K. Takahagi ◽  
E. Sano ◽  
Y. Otsu
Keyword(s):  
High Gain ◽  
Ladder Structure ◽  
Electrically Small Antenna ◽  
Left Handed ◽  
Small Antenna

Novel dual band patch antenna With Gap coupled composite right/left-handed transmission line

2018 ◽  
Vol 11 (1) ◽  
pp. 87-93
Author(s):  
Z. Ahmed ◽  
M. M. Ahmed ◽  
M. B. Ihsan ◽  
A. A. Chaudhary ◽  
J. K. Arif
Keyword(s):  
Transmission Line ◽  
Patch Antenna ◽  
Frequency Ratio ◽  
Unit Cell ◽  
Dual Band ◽  
Rectangular Patch ◽  
Left Handed ◽  
At Resonance ◽  
Low Profile ◽  
Resonance Frequencies

AbstractA novel low profile dual band patch antenna is presented. It consists of a composite right/left-handed transmission line (CRLH TL) unit cell gap coupled with the radiating edge of a rectangular patch antenna. The dual band behavior is achieved by coupling the zeroth order resonance mode of CRLH TL and TM10mode of the patch antenna. It is shown that frequency ratio can be changed by varying the gap between the patch and CRLH TL unit cell. The proposed configuration enables frequency reconfigurability by changing the CRLH TL unit cell using a switch. A prototype of the antenna having frequency ratiof2/f1= 1.08 is designed and fabricated. The proposed antenna shows measuredS11≤ −10 dB bandwidth of 100 and 50 MHz at resonance frequencies off1= 4.84 andf2= 5.22 GHz, respectively. A 2 × 2 dual band CRLH TL coupled patch array is also presented, showing more than 12.7 dBi gain at both resonance frequencies.

scholarly journals SNR Enhancement of an Electrically Small Antenna Using a Non-Foster Matching Circuit

2020 ◽  
Vol 10 (13) ◽  
pp. 4464
Author(s):  
Yong-Hyeok Lee ◽  
Sung-yong Cho ◽  
Jae-Young Chung
Keyword(s):  
Signal To Noise Ratio ◽  
Impedance Matching ◽  
Antenna System ◽  
Broadband Antenna ◽  
Electrically Small Antenna ◽  
Low Dissipation ◽  
Received Power ◽  
Small Antenna ◽  
The Stability ◽  
Dissipation Loss

A non-Foster circuit (NFC) is known as an active broadband matching technique to improve the impedance matching bandwidth of an electrically small antenna (ESA). There has been a vast amount of papers that report the generation of negative impedance using an NFC and its effectiveness on broadband antenna matching. However, only a few discussed its impact on the signal-to-noise-ratio (SNR), which is one of the most important figures-of-merit for a wireless communication system. In this paper, the SNR enhancement due to an NFC was measured and discussed. An NFC was carefully designed to have a low dissipation loss and to meet the stability conditions. The optimized NFC design was fabricated and applied to an ESA length of λ⁄15 at a frequency range of 150 to 300 MHz. The measured results showed that the NFC enhanced the received power of the antenna system by more than 17 dB. However, due to the noise added by the NFC, the SNR enhancement was not guaranteed for some frequency points. Nevertheless, an average of 7.3 dB of SNR improvement over the frequency band of interest is possible based on the experiment result.

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