Design Method for Actively Matched Antennas With Non-Foster Elements

Albarracin-Vargas, Fernando; González-Posadas, V.; Herráiz-Martínez, Francisco Javier; Segovia-Vargas, Daniel

doi:10.1109/tap.2016.2583482

Cited by 9 publications

(7 citation statements)

References 18 publications

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“…The experimental verification of the fabricated non-Foster antenna demonstrates that its corresponding passive Chu-limit is surpassed; it attains a measured 5-times enhancement of the -10-dB fractional bandwidth of the corresponding passive version. it realizes a calculated -3.52 dB peak transducer gain and a 44.5% total efficiency, both of which are significantly higher than other reported designs [20,[23][24][25]. Because the total equivalent noise of a NIC is proportional to the magnitude of its input impedance [20], the reported low-loss, well-matched design also reduces the amount of inevitable noise.…”

mentioning

confidence: 82%

“…As desired, its real part is small in the desired frequency range and remains positive in higher frequency ranges, e.g., 1 to 2 GHz. Again, it is noted that a large positive output resistance would complicate the realization of a matched impedance and it would negatively impact the ESA's radiation performance [23,29]. On the other hand, a large negative output resistance would lead to an oscillating system, i.e., it would be inherently unstable since the total resistance of the system alone would be negative [30,31].…”

Section: B Design Of Nicmentioning

confidence: 99%

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Improved Signal-to-Noise Ratio, Bandwidth-Enhanced Electrically Small Antenna Augmented With Internal Non-Foster Elements

Shi

Tang

et al. 2019

IEEE Trans. Antennas Propagat.

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Non-Foster technology facilitates the ability to surpass the Chu bandwidth limit associated with electrically small antennas (ESAs). Nonetheless, in addition to challenging stability issues, the enhanced performance can come at the cost of increased noise and resistance losses generated by the active circuit. Consequently, low total efficiency and degraded signal-to-noise ratio (SNR) values can arise. Stability and SNR have dominated most reports to date; little has been discussed about the underlying innovative physics of non-Foster augmented radiators. In this communication, we propose a broad bandwidth non-Foster ESA, emphasizing those aspects. By embedding a non-Foster element into the near-field resonant parasitic (NFRP) element of a metamaterial-inspired antenna, its electrically small size is maintained. On the other hand, a 5-times enhancement of its -10-dB fractional bandwidth (15-times its -3-dB bandwidth) is measured, significantly surpassing its passive Chu limit. Under good matching, the measurements demonstrate that this non-Foster ESA achieves a 1.05 dBi peak gain, and realizes average 5.0 dB SNR and 17 dB gain improvements over its passive counterpart. Index Terms-Electrically small antenna, non-Foster circuits, radiation pattern, signal-to-noise ratio I. INTRODUCTIONElectrically small antennas (ESAs) with broadband performance are essential for the development of miniaturized, broadband communication systems for future fifth generation (5G) applications. It is historically known that the physics and engineering associated with ESAs are difficult. Their compact sizes inevitably lead to contradictions between simultaneous bandwidth, efficiency, and directivity performance characteristics [1,2]. They also naturally lead

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mentioning

confidence: 82%

Section: B Design Of Nicmentioning

confidence: 99%

Improved Signal-to-Noise Ratio, Bandwidth-Enhanced Electrically Small Antenna Augmented With Internal Non-Foster Elements

Shi

Tang

et al. 2019

IEEE Trans. Antennas Propagat.

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“… References FBW (%) [Freq. range] Measured Gain (dBi) Size (mm 3 ) NF-IMC topology 18 4.9 [400-420 MHz] 1.05 Not given Relatively simple 19 25.6 [85–110 MHz] 3 73 × 50 × 1.6 Relatively simple 20 66.7 [80–160 MHz] 3 20 × 20 × 0.5 Requires 4 transistors 21 3.6 [1.35–1.45 GHz] Not given 70 × 48 × 0.5 Requires transversal filter using distributed amplifiers & delay lines 22 20 [1.0–1.5 GHz] 5 12 × 12 × 1 Requires four transistors 23 26.1 [100–130 MHz] Not given Not given Relatively simple This work 54.5 [1.4–2.45 GHz] 6.55 56 × 20 × 0.8 Relatively simple …”

Section: Fabricated Prototype and Measurementsmentioning

confidence: 99%

Bandwidth and gain enhancement of composite right left handed metamaterial transmission line planar antenna employing a non foster impedance matching circuit board

Alibakhshikenari

Virdee

Althuwayb

et al. 2021

Sci Rep

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The paper demonstrates an effective technique to significantly enhance the bandwidth and radiation gain of an otherwise narrowband composite right/left-handed transmission-line (CRLH-TL) antenna using a non-Foster impedance matching circuit (NF-IMC) without affecting the antenna’s stability. This is achieved by using the negative reactance of the NF-IMC to counteract the input capacitance of the antenna. Series capacitance of the CRLH-TL unit-cell is created by etching a dielectric spiral slot inside a rectangular microstrip patch that is grounded through a spiraled microstrip inductance. The overall size of the antenna, including the NF-IMC at its lowest operating frequency is 0.335λ0 × 0.137λ0 × 0.003λ0, where λ0 is the free-space wavelength at 1.4 GHz. The performance of the antenna was verified through actual measurements. The stable bandwidth of the antenna for |S11|≤ − 18 dB is greater than 1 GHz (1.4–2.45 GHz), which is significantly wider than the CRLH-TL antenna without the proposed impedance matching circuit. In addition, with the proposed technique the measured radiation gain and efficiency of the antenna are increased on average by 3.2 dBi and 31.5% over the operating frequency band.

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“…The first example is the enhancement of properties of small antennas by adding non-Foster elements into the antenna structure and, therefore, changing its current distribution (it is worth stressing that this approach is radically different from "external" active matching). There are several both theoretical [40] and experimental studies [41][42][43][44] of this idea. The second example is a squint-free leaky wave (LW) antenna based on a transmission line periodically loaded with negative capacitors, proposed in [45] and later analyzed in [46,47].…”

Section: Active Metamaterials and Metamaterials-inspired Devicesmentioning

confidence: 99%

First ten years of active metamaterial structures with “negative” elements

Hrabar

2018

EPJ Appl. Metamat.

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Almost ten years have passed since the first experimental attempts of enhancing functionality of radiofrequency metamaterials by embedding active circuits that mimic behavior of hypothetical negative capacitors, negative inductors and negative resistors. While negative capacitors and negative inductors can compensate for dispersive behavior of ordinary passive metamaterials and provide wide operational bandwidth, negative resistors can compensate for inherent losses. Here, the evolution of aforementioned research field, together with the most important theoretical and experimental results is reviewed. In addition, some very recent efforts that go beyond idealistic impedance negation and make use of inherent non-ideality, instability, and non-linearity of realistic devices, are highlighted. Finally, a very fundamental, but still unsolved issue of common theoretical framework that connects causality, stability, and non-linearity of networks with negative elements is stressed.

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Design Method for Actively Matched Antennas With Non-Foster Elements

Cited by 9 publications

References 18 publications

Improved Signal-to-Noise Ratio, Bandwidth-Enhanced Electrically Small Antenna Augmented With Internal Non-Foster Elements

Improved Signal-to-Noise Ratio, Bandwidth-Enhanced Electrically Small Antenna Augmented With Internal Non-Foster Elements

Bandwidth and gain enhancement of composite right left handed metamaterial transmission line planar antenna employing a non foster impedance matching circuit board

First ten years of active metamaterial structures with “negative” elements

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