Accurate Models of Time-Invariant Beampatterns for Frequency Diverse Arrays

This letter presents the mutual coupling reduction in Fabry-Pérot (FP) cavity antenna array. Partially reflecting surface (PRS) and analogous artificial magnetic conductor reflectarray in the cavity participate in phase and magnitude modulation with spatial decoupling solution. With the proper design for the cells of PRS and reflectarray, along with the distance between them, scattered and surface waves are analyzed independently to achieve the trade-off between mutual coupling reduction and high directivity. With decoupling optimization, S 21 decreases from −20 to −30 dB, and the gain of the decoupling FP cavity antenna array fed by single source drops acceptably from 14.3 to 13.6 dBi simultaneously. The low E-plane coupling coefficient and envelope correlation coefficient are achieved. Besides, the height of the decoupling FP cavity antenna array is lower than 6.3 mm owing to the participation of reflectarray. That the measured results are in good agreements with simulated results verifies the decoupling FP cavity antenna array performances.

show abstract

“…For instance, the time-invariant beampatterns can be transformed from theory to reality based on the decoupling method. 32…”

Section: Discussionmentioning

confidence: 99%

Mutual coupling reduction in Fabry‐Pérot cavity antenna array

Zhan

Liu

et al. 2020

Micro & Optical Tech Letters

View full text Add to dashboard Cite

show abstract

“…It can be seen that the beampattern peaks in all schemes are propagated along the distance as time elapses, confirming the findings in Chen et al and Ding and Narbudowicz. [11][12][13] Distinctively, only a single maximum at a time instant for the proposed log-RFDA and the log-FDA can be observed, that is, nonperiodicity beampattern in the range domain. In addition, in Figure 4A, it can be observed that the time-range relationship of the beampattern propagation can be met in the proposed log-RFDA scheme.…”

Section: Beampattern Simulations and Comparisonsmentioning

confidence: 97%

“…This aspect has been recently pointed out and proved in Chen et al and Ding and Narbudowicz. [11][12][13] In Chen et al, 11 the time-independent beampattern for a given range-angle pair was revisited with the consideration of the time-range relationship. This concept was further studied in Chen et al, 12 suggesting that the time-independent beampatterns cannot be achieved in practical free space applications.…”

Section: Introductionmentioning

confidence: 99%

“…[11][12][13] In Chen et al, 11 the time-independent beampattern for a given range-angle pair was revisited with the consideration of the time-range relationship. This concept was further studied in Chen et al, 12 suggesting that the time-independent beampatterns cannot be achieved in practical free space applications. Meanwhile, the CFDA and its variants for physical-layer wireless security was carefully examined in Ding and Narbudowicz, 13 proving that the CFDA cannot secure a free-space wireless transmission in the range domain because that the claimed security in range domain is time-dependent and the "secure region" propagates with time.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Frequency diverse array with random logarithmically increasing frequency offset

Huang

Ding

Ouyang

et al. 2020

Micro & Optical Tech Letters

View full text Add to dashboard Cite

The frequency diverse arrays (FDAs) have been extensively investigated since it can provide a unique anglerange-dependent beampattern. This range-dependent characteristic can suppress the range ambiguous clutters, leading to many novel potential Radar applications. Two issues, however, exist in conventional FDA (CFDA) beampatterns, that is, range-angle coupling and range periodicity. Therefore, for a CFDA Radar, target range information cannot be obtained directly from the beampattern peaks and target ambiguity occurs in the range domain. In this work, a new frequency diverse array (FDA) transmitter architecture with random logarithmically increasing frequency offset (log-RFDA) is presented. It is shown that the proposed strategy provides a nonperiodic thumbtack-like beampattern, eliminating the ambiguity in range domain, suffered in the CFDA Radar. Furthermore, reduced side lobe and higher detection resolution can be achieved, compared with the previously reported log-FDA. K E Y W O R D Sfrequency diverse arrays, higher detection resolution, nonperiodic thumbtacklike beampattern, random logarithmically increasing frequency offset

show abstract

“…Therefore, in both cases, the beampattern will be zero. The work in [22], [23] modify the FDA signal model by incorporating the propagation delay t o .…”

Section: Introductionmentioning

confidence: 99%

Frequency Diverse Array Radar: New Results and Discrete Fourier Transform Based Beampattern

Zubair

Ahmed

Alouini

2020

IEEE Trans. Signal Process.

View full text Add to dashboard Cite

In the phased-array radar (PAR) signals from each antenna are transmitted at the same carrier frequency, which yields narrowly focused only angle dependent beampattern. In contrast, in the frequency-diverse-array (FDA) radar signals from antenna array are generally transmitted at linearly increasing frequencies that yields range, time, and angle dependent beampattern. Reported literature on FDA radar missed the contribution of path-differences in the signal model due to the antenna array elements, which may lead to misleading results. In this work, incorporating missed path-differences, the signal model of FDA radar is corrected. Using the corrected signal model, it is shown that the instantaneous beampattern depends on the number of transmit antenna and average beampattern depends on the product of frequency-offset and pulse-duration. Moreover, to illuminate the desired region-of-interest for longer dwell time, discrete-Fourier-transform based low-complexity algorithm is proposed. In contrast to the conventional FDA radar's 'S' shaped beampattern, the beampattern of the proposed algorithm changes linearly with range. Simulation results compare the performance of our proposed algorithm with the existing ones and show the superiority of our proposed algorithm.Index Terms-Frequency-diverse-array radars, Linear and non-linear frequency offset, Time and range dependent beampattern, Discrete-Fourier-transform.

show abstract

Accurate Models of Time-Invariant Beampatterns for Frequency Diverse Arrays

Cited by 85 publications

References 24 publications

Mutual coupling reduction in Fabry‐Pérot cavity antenna array

Mutual coupling reduction in Fabry‐Pérot cavity antenna array

Frequency diverse array with random logarithmically increasing frequency offset

Frequency Diverse Array Radar: New Results and Discrete Fourier Transform Based Beampattern

Contact Info

Product

Resources

About