Non-Foster Matched Antennas for High-Power Applications

Jacob, Minu M.; Sievenpiper, Daniel F.

doi:10.1109/tap.2017.2727513

Cited by 26 publications

(9 citation statements)

References 13 publications

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“…As noted in earlier work by the author [18], the notion of gravitational Q developed here is distinct from the notion of mechanical Q of cryogenic spherical gravitational antennas in Merkowitz et al [19]. Lastly, it should also be noted that recent non-Foster and metamaterial experiments show results much better than the electromagnetic Chu limit would permit, suggesting the potential that the proposed gravitational Q concepts could lead to similar gravitational detector enhancements [20][21][22].…”

Section: Introductionmentioning

confidence: 65%

“…Since Q provides a measure of the ratio of stored energy to radiated energy in electromagnetic fields of antennas, it is hoped that gravitational Q may offer similar utility in gravitational field analysis. In addition, Q is useful in the design of methods to enhance signal coupling from electromagnetic antennas, such as non-Foster, metamaterial, and passive-tuning methods [20][21][22]. Although the focus of the present work has been on gravitational radiation sources, similar results should apply to gravitational detectors under reciprocity considerations and the gravitationally-small dimensions of terrestrial detectors.…”

Section: Resultsmentioning

confidence: 99%

“…Although the focus of the present work has been on gravitational radiation sources, similar results should apply to gravitational detectors under reciprocity considerations and the gravitationally-small dimensions of terrestrial detectors. Finally, the proposed gravitational Q concepts may lead to future gravitational detector design approaches, since recent non-Foster and metamaterial experiments have shown results much better than the electromagnetic Chu limit would permit [20][21][22].…”

Section: Resultsmentioning

confidence: 99%

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Theoretical and observed quality factor of gravitational quadrupoles

Weldon

2018

Phys. Rev. D

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Useful insights into the complicated physics of gravitational waves can often be drawn from approximations to analogous physics of electromagnetic waves. Here, we present a gravitational form of the electromagnetic Chu limit that sets bounds on the achievable Q (quality factor) relating the ratio of stored energy to radiated energy in the underlying fields. In particular, we answer two fundamental physics questions: 1) what is the theoretical Q for gravitational quadrupole radiation sources, and 2) can gravitational Q be observed from recent measured astronomical data? Gravitational Q is shown to follow an inverse seventh-order power law, and gravitational-wave data is used to find observed values of Q for GW170817. Inasmuch as electromagnetic Q serves a central role in design and analysis of electrically-small antennas, the proposed gravitationalQ offers the potential for a similar utility in the design and analysis of gravitationally-small detectors and quadrupoles.

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Section: Introductionmentioning

confidence: 65%

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

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Theoretical and observed quality factor of gravitational quadrupoles

Weldon

2018

Phys. Rev. D

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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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“…Here a two-level methodology for the stability analysis of complex systems is proposed, which formalizes an idea used in [34]- [35] for the small-signal stability analysis of non-Foster networks [36]- [37]. In addition, it addresses the significantly more complex case of the large-signal stability analysis.…”

Section: Introductionmentioning

confidence: 99%

Two-Level Stability Analysis of Complex Circuits

Suárez

Ramírez

2021

IEEE Trans. Microwave Theory Techn.

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A new methodology is proposed for the small-and large-signal stability analysis of complex microwave systems, containing multiple active blocks. It is based on a calculation of the system characteristic determinant that ensures that this determinant does not exhibit any poles in the right-hand side of the complex plane (RHS). This is achieved by partitioning the structure into simpler blocks that must be stable under either open-circuit (OC) or shortcircuit (SC) terminations. Thus, the system stability is evaluated by means of a two-level procedure. The first level is the use of pole-zero identification to define the OC-or SC-stable blocks, which, due to the limited block size, can be applied reliably. In large-signal operation, the OC-or SC-stable blocks are described in terms of their outer-tier conversion matrices. The second level is the calculation and analysis of the characteristic determinant of the complete system at the ports defined in the partition. The roots of the characteristic determinant define the stability properties. The Nyquist criterion can be applied since, by construction, the determinant cannot exhibit any poles in the RHS. In addition, one can use pole-zero identification to obtain the values of the determinant zeroes. Because the determinant is calculated at a limited number of ports, the analysis complexity is greatly reduced.

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Non-Foster Matched Antennas for High-Power Applications

Cited by 26 publications

References 13 publications

Theoretical and observed quality factor of gravitational quadrupoles

Theoretical and observed quality factor of gravitational quadrupoles

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

Two-Level Stability Analysis of Complex Circuits

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