Isolation enhancement of densely packed array antennas with periodic MTM-photonic bandgap for SAR and MIMO systems

Abstract

A metamaterial photonic bandgap (MTM-PBG) periodic structure is used as a decoupling frame to improve the isolation between transmit-receive (T/R) sections of densely packed array antenna in synthetic aperture radar (SAR) and multiple-input multiple-output (MIMO) systems. With this technique the MTM-PBG structure is shown to effectively suppress surface wave propagations between the T/R array antennas by an average of 12 dB. MTM-PBG layer comprises a periodic arrangement of dielectric circles etched in the cross-shaped microstrip frame that is inserted between the radiating elements. Unlike other recently reported methods, the advantages of the proposed technique are: (i) simplicity; (ii) cost effectiveness as there is no need for short-circuited via-holes or 3D metal walls; and (iii) can be retrofitted in existing array antennas. The proposed T/R array antennas were designed to operate over an arbitrary frequency range (9.25-11 GHz) with a fractional bandwidth (FBW) of 17.28%. With this technique (i) the side-lobes are reduced; (ii) there is minimal effect on the gain performance; and (iii) the minimum edge-to-edge gap between adjacent radiating elements can be reduced to 0.15 at 9.25 GHz.

A Comprehensive Survey on “Various Decoupling Mechanisms With Focus on Metamaterial and Metasurface Principles Applicable to SAR and MIMO Antenna Systems”

“…In [134] an MTM photonic bandgap (PBG) periodic structure is utilized as an isolator slab to repress the mutual coupling in densely packed array antenna for SAR and MIMO applications as displayed in Fig.20. By this method, the MTM PBG layout is exhibited to efficiently reduce surface-wave distributions between the patch arrays by an average of 12dB, see Table XII.…”

“…This explains that the radiation specifications are not intensely influenced by realizing the MTM PBG decoupling frame. empirical Sparameters of the arrays without (WO) and with (W) proposed isolator, (f) input impedances (Ω) after apply the periodic MTM-PBG isolator, (g) circuit model including MTM-PBG isolator sheet, (h) gain curve, (i) radiation efficiency curve, and (j) experimental radiation patterns before and after the periodic MTM-PBG isolator [134]. Table XIII shows comparisons in the performance parameters of the abovementioned techniques relative to the studied literature in terms of the mutual coupling reduction techniques, maximum isolation improvement, number of applied elements in the array structure, design complexity and simplicity, impact on the size after applying the technique, and augmentation and development of the array after applying the technique.…”

Radiation performance enhancement of an ultra wide band antenna using metamaterial band-pass filter

“…These last are a composite media made up of an arrangement of metal structures on the surface of dielectric substrates. They can be engineered to have unique electromagnetic properties and integrated after in antenna design to exhibit many application requirements [4][5][6]. In other researches, metamaterials structures are applied in RFID (radio frequency identification) tags in order to augment the read range and to decouple the tag with the tagged object [7].…”

High Efficiency X-Band Series-Fed Microstrip Array Antenna

“…It has been shown that mutual coupling among neighboring radiating elements in the antenna can be improved by increasing the space between the elements, but this is at the cost of increased antenna size [20]. Many techniques have been investigated to reduce mutual coupling between elements, which include using metamaterials [21][22][23][24][25], metasurface [26][27][28], and embedded periphery slot [29]. The results show that the presence of these components close to a radiating element can affect its resonant frequency.…”