Reduction of Mutual Coupling and Return Loss in Microstrip Array Antennas Using Concave Rectangular Patches

Abstract

An effective solution to reduce both the mutual coupling and return loss of a microstrip array antenna consisting of rectangular patches is proposed. The patch is made concave in both horizontal and vertical sides. Applying the proposed structure to a microstrip array antenna having two elements, the effects of patch concavity on the mutual coupling and return loss are simulated and studied. To obtain a concave rectangular patch array antenna having low amounts of mutual coupling and return loss, the patch length and width as well as the amounts of concavities are optimized using an enhanced genetic algorithm. To verify the simulation results, then, the optimal array antenna is fabricated. The simulation and experimental results confirm that the optimal concave rectangular array antenna has low amounts of mutual coupling and return loss.

Lessons Learned about the Design and Active Characterization of On-Body Antennas in the 2.4 GHz Frequency Band

“…A mismatch between the experimental results and simulations can be observed in Figures 7 and 8. Probable causes of the differences may be the losses attributable to the elements not considered in the design and simulation phase: uncertainties due to the manufacturing process, calibration or measurement errors, finite ground plane effects, influence of the metallic and electronic components of the device's complete hardware, properties of the transceiver and the communications protocol, but also other losses derived from the front-end of the measurement equipment, such as possible signal losses by impedance mismatch in the Tx or Rx antennas, in the coaxial cable that connects them to the spectrum analyzer or in the connectors [59][60][61][62][63][64]. It was not possible to perform any type of calibration to remove the losses associated with the transceiver interfaces, since it was not possible to establish any reference in the received signal if the battery-powered transceiver was used as transmitter.…”

“…Under normal circumstances, the standard method provides an effective way to evaluate antenna performance, with good correspondence between the simulation results and the experimental results. However, sometimes these differences can be important as a result of the loss of control in the elements that influence the antennas or external effects [60][61][62][63][64][65][66]. The proposed method, despite its higher complexity, assumes many of the effects that can influence the performance of the antennas, so it can represent a better approach to reality.…”

Mutual Coupling Reduction in Microstrip Array Antenna by Employing Cut Side Patches and Ebg Structures

“…To overcome this problem in microstrip array antennas, various methods, such as Split-Ring Resonators (SRR) [4], concave patches [5], waveguide-based metasurfaces [6], and defected ground structures (DGS) [7] have been presented. Although these techniques may provide noticeable mutual coupling reduction, they may have some drawbacks.…”

“…The replacement of conventional patches with concave patches can slightly improve the mutual coupling through a straightforward approach. However, this approach slightly reduces the gain of each element, due to the reduction of effective aperture of each element [5].…”

Τεχνολογίες Ενεργειακά Αποδοτικών Ευρυζωνικών Και Συμπαγών Κεραιοσυστημάτων Υψηλών Συχνοτήτων Για Κινητά Τερματικά Και Προηγμένα Ασύρματα Δίκτυα Επικοινωνιών

“…Μια διαφορετική προσέγγιση καταπίεσης ακολούθησαν οι Mohanna et al[215] οι οποίοι, αντί να σχεδιάσουν κάποιο τύπο αποσυζεύκτη, παραμόρφωσαν το σχήμα των κεραιοστοιχείων. Δύο μικροταινιακές κεραίες εκτυπώθηκαν σε υπόστρωμα με κοινό επίπεδο γείωσης διαστάσεων 1.29λ × 1.96λ σε απόσταση d = 0.4λ.…”