Efficient Transition Hybrid Two-Layer Feed Network: Polarization Diversity in a Satellite Transceiver Array Antenna

Int J RF Mic Comp-Aid Eng

et al. 2022

Self Cite

The most important limitation in using orbital angular momentum (OAM) multiplexing in communication is the range, so that because of OAM beam propagation, it cannot be used in the long range. It was found that when several original OAM modes were superimposed together, the concentrated EM wave in a certain angular range, with its effective phase diagram, could constitute a new quasi-OAM (QOAM) mode. In this article, the superposition of multiple OAM modes for beam concentration using uniform circular array is presented to in order to realize long-range communication. The simulation results show that the orthogonality characteristic of the two QOAMs produced by the proposed method is more than 10 decibels.

Section: Full Wave Validationmentioning

confidence: 99%

Section: Full Wave Validationmentioning

confidence: 99%

Studying superposition of multiple orbital angular momentum modes for beam concentration using circular arrays for long‐range communication

Daronkola

Hamedani

Int J RF Mic Comp-Aid Eng

et al. 2022

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“…To suppress the leakage of the EM energy, the diameters of the metallic vias, which form the SIW cavity, should meet two criteria including

\frac{S}{d} \leq 2

and

\frac{d}{λ_{0}} \leq 0.1 .

12 The dimensions of the SIW cavities determines the resonance frequency. The primary dimensions of the SIW cavities can be derived by using a closed‐form formula 13,14 when the effects of the metallic vias are ignored:

f_{mnp} = \frac{C}{2 \sqrt{ε_{normalr}}} \sqrt{{(\frac{m}{{Wcs}_{eff}})}^{2} + {(\frac{n}{{Lcs}_{eff}})}^{2} + {(\frac{p}{h})}^{2},}

{Lc}_{eff} = L_{c} - 1.08 \frac{d^{2}}{S} + 0.1 \frac{d}{L_{normalc}},

{Lcs}_{eff} = L_{cs} - 1.08 \frac{d^{2}}{S} + 0.1 \frac{d^{2}}{L_{cs}},

where ε r is permittivity of the substrate ( ε r = 3.55) and f mnp is the resonance frequency of the cavity modes. m , n , and p are integers in (1) which can be assumed as m = 1, and n = 1 and P = 0 for the dominant propagation mode in the SIW channels.…”

Section: Antenna Designmentioning

confidence: 99%

A compact and wideband array antenna with efficient hybrid feed network

Karami

Int J RF Microw Comput Aided Eng

Amn‐e‐Elahi

et al. 2020

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This study presents a high-efficient, compact, and broadband microstrip patch antennas (MPAs) based on substrate-integrated waveguide (SIW) for X-band applications. The proposed array consists of three stacked layers from top to bottom, including one layer as the antenna layer and two SIW layers as a feeding network. The performance was focused on improving the impedance bandwidth and radiation efficiency by mitigating the loss from the feed network while also maintaining the compact design. To this end, the SIW feeding network was designed to feed the MPA to save the physical aperture size which resulted in a more compact and efficient radiating structure. The overall size of the proposed array is compact and extra surface area around the radiation aperture has not been occupied. The measured −10 dB impedance bandwidth span is from 8.9 to 10.9 GHz (20.2%). The maximum measured gain at 10.6 GHz is 10.6 dBi. The results show that the simulated radiation efficiency and the measured aperture efficiency are more than 75% and 50%, respectively. The fabricated array exhibits great advantages such as wide operating bandwidth, lightweight, low-cost, high aperture efficiency, high radiation efficiency, and compactness which make it a good candidate for X-band applications.

“…Due to all these reasons, the conformal array has received more and more attention in the areas such as aircraft, high-speed train, and guided missile. [1][2][3][4][5] Nevertheless, the conformal array has many unique electromagnetic characteristics compared to the ordinary array, 6 such as shadowing effect caused by the geometry structure. These will increase the complexity in the direction-of-arrival (DOA) estimation and to resolve these types of problems in the conformal array many different methods have been studied and proposed.…”

Section: Introductionmentioning

confidence: 99%

DOA estimation accuracy improvement by solving the rank reduction algorithm ambiguous parameters through synthesizing the volume antenna beam pattern

Sharifi

Int J RF Mic Comp-Aid Eng

Mohammadi

2022

Self Cite

This article focuses on increasing the accuracy of Directional-of-Arrival (DOA) estimation by synthesizing the Conformal Uniform Circular Array (CUCA) and uses the Rank Reduction (RARE) algorithm to minimize the mutual coupling and shadowing impacts on the array performance. After separating the azimuthal angles from all of the unknown information by transforming the CUCA from the element space to the mode space, the RARE algorithm is applied in the estimated azimuthal angles. Also, the ambiguous values of π exist in the RARE algorithm are solved by forming the CUCA beam pattern. Due to the fact that the accurate measuring or estimating the mutual coupling and shadowing effects are difficult, one of the most important achievements of this work is that there is no need to measure the mutual coupling and shadow effect. Also, the CUCA aperture is not reduced compared to use the subarray methods as another advantage. The simulation results significantly confirm the presented method's benefits.