Decoupling of Two Closely Located Dipole Antennas by a Split‐Loop Resonator

Abstract

In this paper, we theoretically and experimentally prove the possibility of the passive electromagnetic decoupling for two parallel resonant dipoles by a split‐loop resonator having the resonance band overlapping with that of the active dipoles. We show that the replacement of the decoupling dipole suggested in the literature as a tool for decoupling of two closely located dipole antennas by our split‐loop resonator results in the twofold enlargement of the operation band.

Double-resonant decoupling method in very dense dipole arrays

“…In [11], these decoupling conditions were satisfied by two passive dipoles identical to the active dipoles but shortcut at the center. It is possible to prove that replacing these passive dipoles by passive SLRs allows to satisfy these equations as well [12]. However, equation (2) cannot be for resonant SLRs reduced to the same form (3), like it was done in [11] for resonant dipoles.…”

“…In the case of SLRs it is not so. Decoupling condition for the adjacent dipoles (3) is analytically solved in [12] and the condition is satisfied at the frequency ω ≈ 1.0432ω 0 (proper dimensions for SLR to decouple two dipoles are calculated based on this analytical solution). Decoupling condition for the distant dipoles (2) is numerically solved.…”

“…Second one is the magnetic-dipole component, related to the asymmetric part of the SLR current. For electric-dipole component the problem was solved in [12]. For the magnetic-dipole component the problem can be solved in principle also analytically.…”

“…For the reference case (no SLRs) coupling coefficients for the adjacent dipoles at the resonant frequency f 0 in the mismatched and matched regimes are nearly equal −5 dB and −2 dB, respectively. Introducing 2 SLRs with following geometric parameters (based on analytical solution in [12]) -L 1 = 322 mm, h = 10 mm, g = 30 mm, r 0 = 1 mm, and d = 30 mm -between the dipoles as shown in figure 1(a), we come to the results presented in figure 2.…”

“…Using this approach, transmittance coefficient between active dipoles has been decreased from -2dB (for the reference case -without passive dipoles) to -13 dB while the relative bandwidth was 0.5% at the level of -8 dB. Then in work [12], we have enhanced decoupling bandwidth between two active dipoles through replacing the passive dipole of [11] with a split-loop resonator (SLR). However, no one has used two and more SLRs to decouple dense arrays of dipole antennas.…”