A reconfigurable MIMO handset antenna employing liquid metal

This paper presents a reconfigurable MIMO handset antenna based on liquid metal. The antenna covers the eight frequency bands of the LTE-A standard. This antenna comprises: a monopole element, a IFA element, and a dual-purpose L-shaped branch which is connected to the ground plane. The function of the L-shaped branch is to improve the isolation, within the low frequency band (698-960 MHz), between two elements. A strip of liquid metal which connects to the arm of the IFA, coordinated with the L-shaped branch, can be used to alter its resonant frequency. The operating principle of this strip is analysed using an equivalent capacitor model. The theory of characteristic mode is used to analyze the properties of proposed antenna. To validate the concept, a prototype antenna with size of 120 × 60 × 0.8 mm³ was fabricated and measured.