On Mutual Coupling and Coupling Paths Between Antennas Using the Reaction Theorem

Malmström, Johan; Holter, H.; Jonsson, B. L. G.

doi:10.1109/temc.2017.2771512

“…The method proposed here is a generalization of [10], [11], both of which are also based on the reciprocity theorem. One of the important extensions in this work is that the proposed method automatically handles arbitrary complexvalued self-impedances for the antennas, as well as both well and poorly matched impedances.…”

Section: Introductionmentioning

confidence: 99%

Visualization and Reduction of Mutual Coupling Between Antennas Installed on a Platform

Lundgren¹,

Malmström²,

Hannula³

et al. 2021

Preprint

Self Cite

View full text Add to dashboard Cite

Mutual coupling, or equivalently, the isolation between antennas, is a key parameter in antenna system design. In this work, a new quantity is proposed to obtain spatial information about mutual coupling. The new quantity is named the weak-coupling density. This quantity is a real-valued scalar and can be visualized as a three-dimensional density in space. It is also shown that there is a strong correlation between regions with a positive (negative) weak-coupling density and decreasing (increasing) the coupling when placing an absorber in that region. This predictive ability is a useful feature, which is tested here for three numerical cases. The results are robust to the shape of the platform, and it persists over neighboring frequencies. By placing absorbers based on the weak-coupling density, it is possible to reduce the required amount of absorbers to obtain a certain mutual coupling reduction. The visualization results and predictions of absorber positions are compared with a Poynting vector based method. Placing absorbers based on the weak-coupling density had a larger impact on the mutual coupling, compared to the predictions with the Poynting vector based method in the investigated cases.

show abstract

“…Therefore, δ is referred to as the weak-coupling density. A related approach was considered in [10] where the impedance density was defined.…”

Section: Coupling Visualization Using the Reaction Theoremmentioning

confidence: 99%

“…Visualization methods are therefore useful tools for identifying regions in space with strong contributions to the mutual coupling. A path between a transmitting and receiving antenna that depicts the spatial contribution to the mutual coupling is referred to as a coupling path [10], [11].…”

Section: Introductionmentioning

confidence: 99%

“…The method uses reciprocity and it is based on the reaction theorem [13], [14]. The quantity proposed here is referred to as the weak-coupling density and has similarities with the impedance density defined in [10]. However, the weak-coupling density is real-valued and it is valid for non-ideal sources, which simplifies the calculation and makes the interpretation of the results straightforward.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Visualization and Reduction of Mutual Coupling Between Antennas Installed on a Platform

Lundgren¹,

Malmström²,

Hannula³

et al. 2020

Preprint

Self Cite

View full text Add to dashboard Cite

Mutual coupling, or equivalently, the isolation between antennas, is a key parameter in antenna system design. In this work, a new quantity is proposed to obtain spatial information about mutual coupling. The new quantity is named the weak-coupling density. This quantity is a real-valued scalar and can be visualized as a three-dimensional density in space. It is also shown that there is a strong correlation between regions with a positive (negative) weak-coupling density and decreasing (increasing) the coupling when placing an absorber in that region. This predictive ability is a useful feature, which is tested here for three numerical cases. The results are robust to the shape of the platform, and it persists over neighboring frequencies. By placing absorbers based on the weak-coupling density, it is possible to reduce the required amount of absorbers to obtain a certain mutual coupling reduction. The visualization results and predictions of absorber positions are compared with a Poynting vector based method. Placing absorbers based on the weak-coupling density had a larger impact on the mutual coupling, compared to the predictions with the Poynting vector based method in the investigated cases.

show abstract

“…Moreover, with the increasing use of radar technology and its frequency spectrum requirements, radar signals that coexist within the same bandwidth face the severe threat of the mutual interference [6]. References [7] and [8] studied antenna coupling problems, pointing out that the coupling of antennas for two radars could cause mutual interference. Thayaparan et al [9] investigated the mechanisms of mutual interference and pointed out that mutual interference could lead to problems such as ghost targets and a reduced signal-to-noise ratio (SNR).…”

Section: Introductionmentioning

confidence: 99%

Antijamming Design and Analysis of a Novel Pulse Compression Radar Signal Based on Radar Identity and Chaotic Encryption

Dai

¹

,

Hao

²

,

Li

³

et al. 2020

View full text Add to dashboard Cite

As the use of radar and radar jammers increases, a radar device is likely to face interference from jammers or other radar devices. Traditional phase-coded pulse compression radar devices are widely used, but these tools struggle to overcome jamming and mutual interference. To solve this problem, we propose a novel chaotic-encrypted pulse compression radar signal based on radar identity (ID). Each radar has its own ID, which is encrypted with different chaotic binary sequences in every pulse period. The ambiguity function calculated for the coded radar signal is thumbtack-shaped, indicating that the signal has a good resolution. The received signal is used to range and decrypt in two channels: the range channel and the radar ID channel. The signals of the two channels are analyzed separately. Analyses of anti-barrage jamming and antimutual interference show that both channels perform well in terms of antijamming, while the antijamming ability is influenced by the processing gain, bit error rate (BER) and correlation function. In addition, the dual-channel antijamming method further improves the radar antijamming ability. The simulation result verifies the strong antijamming ability and high range resolution of the proposed radar signal, and the proposed antijamming method performs much better than the traditional phase-coded pulse compression radar signal in the antijamming scenario. INDEX TERMS Pulse compression radar, radar ID, chaotic encryption, mutual interference, antijamming ability.

show abstract

On Mutual Coupling and Coupling Paths Between Antennas Using the Reaction Theorem

Cited by 36 publications

References 16 publications

Visualization and Reduction of Mutual Coupling Between Antennas Installed on a Platform

Visualization and Reduction of Mutual Coupling Between Antennas Installed on a Platform

Visualization and Reduction of Mutual Coupling Between Antennas Installed on a Platform

Antijamming Design and Analysis of a Novel Pulse Compression Radar Signal Based on Radar Identity and Chaotic Encryption

Contact Info

Product

Resources

About