Antenna apparatus integrating metal shell

An antenna apparatus includes a metal shell, a circuit board parallel to the metal shell which forms a space between the circuit board and the shell, a tunable matching circuit mounted in the space with an terminal electrically connected to the shell, and an capacitive feed coupling antenna mounted on the circuit board. The capacitive feed coupling antenna includes a coupling ground strip mounted on the circuit board and a feed strip. The feed strip includes a first portion and a second portion mounted on the circuit board with a portion extending along an edge of the circuit board. The first portion is electrically interconnected between the other terminal of the tunable matching circuit and the second portion.

BACKGROUND

1. Technical Field

The present disclosure relates to antennas, and particular to an antenna apparatus integrating a metal shell of an electronic device employing the antenna apparatus.

2. Description of the Related Art

Electronic devices commonly employ metal shells to cover and accommodate circuit boards and antennas. The metal shell usually generates shield which reduces efficiency of the antenna. Therefore, the electronic device has to be more complicatedly installed to avoid the shield generated by the metal shell, which will increase cost. Furthermore, sometimes there is not enough space for allocating the metal shell and the antenna due to the electronic device.

Therefore, there is room for improvement within the art.

DETAILED DESCRIPTION

Referring toFIG. 1, an antenna apparatus1includes a metal shell10of an electronic device (not shown), a circuit board11, an capacitive feed coupling antenna12, and a tunable matching circuit13. The metal shell10includes a continuous bent metal strip100, and configured for attaching to a housing15of the electronic device to form a loop. The circuit board is mounted in the electronic device and parallel to the metal shell10, keeping a distance away from the shell10to form a space14between the circuit board11and the shell10. In the embodiment, the metal shell10is generally C-shaped.

The capacitive feed coupling antenna12is conductive and formed by a bended strip metal. The capacitive feed coupling antenna12includes a coupling ground strip120, a feed strip121, and a feed point122. The coupling ground strip120is mounted on the circuit board11. The feed strip121includes a first portion121aand a second portion121b.The first portion121aand the tunable matching circuit13are mounted in the space14. In detail, one terminal of the tunable matching circuit13is mounted on the shell10, and the other terminal of the tunable matching circuit13is connected to an end of the first portion121a.The other end of the first portion121ais connected to the second portion121b,and perpendicular to the circuit board11. The second portion121bis mounted on the circuit board11with a portion extending along an edge110of the circuit board. Thereby, the shell10is integrated with the capacitive feed coupling antenna12, forming a double mimicry loop. The frequency band of the antenna apparatus1can be adjusted by changing parameters of the tunable matching circuit13or the capacitive feed coupling antenna12.

Referring toFIG. 2, in the embodiment, the tunable matching circuit13includes an inductance130, the first portion121aof the feed strip121is connected to the shell10via the inductance130. In an alternative embodiment, the tunable matching circuit13includes a capacitor, or a capacitor and an inductance.

It is understood that the present disclosure may be embodied in other forms without departing from the spirit thereof. The present examples and embodiments are to be considered in all respects as illustrative and not restrictive, and the disclosure is not to be limited to the details given herein.