An inverted L-shaped antenna pair with high isolation characteristics for mobile terminals with zero ground clearance

ABSTRACT

An inverted L-shaped antenna pair that can be applied to zero-ground-clearance mobile terminal equipment is presented. One inverted L-shaped antenna was placed on the frame of a mobile terminal and the other on the ground near the frame. The two antennas were placed in parallel, 4 mm apart, and a neutralisation line was introduced between them to achieve decoupling. The neutralisation line was integrated with an inverted L-shaped antenna introduced above the ground, which did not occupy any other installation space. The installation space occupied by the antenna pair was 17 × 8 × 6.2 mm³ (0.2 × 0.09 × 0.07 λ³). The measured results show that the − 6 dB impedance bandwidth of the antenna is 3.29–3.64 GHz, the isolation in the 3.3–3.6 GHz band is greater than 19.5 dB, the envelope correlation coefficient (ECC) is less than 0.3, and the antenna efficiency is 77.6–99.8%.

KEYWORDS:

• Antenna pair
• MIMO
• mobile terminal
• neutralisation line
• zero ground clearance

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported in part by the National Natural Science Foundation of China (No. 61971335, No. 61401336).