A decoupling method for MIMO antenna using trifurcation elements

Abstract

Technology of MIMO using multiple antennas and Carrier Aggregation operating multiple frequency bands are introduced in a mobile terminal to improve communication capacity. However, if plural MIMO antennas are installed closely, mutual coupling between the antennas must be reduced to suppress deterioration of radiation efficiency and increase of correlation coefficient. In this paper, we proposed a decoupling method for dual-band using trifurcation elements. Moreover, it is confirmed to be broadened decoupling bandwidth by optimizing branch width and length.

A Dual-Band Decoupling Method of 2 Elements MIMO Antennas by Using a Short Stub and a Branch Element

“…Therefore, considering the characteristic of change the current path by L or C, method of trifurcation element is also proposed [11]- [13]. ([12] focus on proposing new decoupling method.…”

“…However, reference [13] doesn't propose a novel decoupling method but mentions broadband for trifurcation decoupling. Reference [11] summarizes these articles.) Figure 1 shows equivalent current path length at the excitation of left feed port.…”

“…However, the wiring is required to connect the antenna via the lumped element (L or C), and the resistance of the lumped element causes power loss as well. Hence, the method of using an antenna shape of three elements with different length without lumped element is proposed instead of the susceptance circuit [11]- [13]. In this method, it is necessary to use the desired length element for the operation frequency.…”

A Non-Connected Decoupling Method for Three Element MIMO Antennas by Using Short Stubs

“…As the countermeasure of narrow band, in Ref. [7], element width is widened to broaden bandwidth, thus, we applied this method to our proposed model.…”

“…[7], widening bandwidth is considered. We applied this study [7] to our proposed method. Section 2 explains the decoupling condition and previous decoupling methods of connecting elements, and then, we explain the technique of decoupling between ends antenna in Ref.…”