Patent ID: 9123989
Filing Date: 2015-09-01
Classification: H01Q

Abstract:
1. An antenna device, comprising: a first antenna, configured to transmit an RF signal; an antenna detection circuit, comprising an inductor configured to detect a second antenna and directly connected between the second antenna and a ground terminal, wherein when the second antenna is absent, the inductor serves as an open-circuit path for a high-frequency signal, when the second antenna is present, the inductor serves as a short-circuited path for a low-frequency signal; a switch control circuit, coupled to the antenna detection circuit, configured to receive an antenna detection signal generated by the open-circuit path or the short-circuit path to generate a first control signal indicative of the presence of the second antenna upon the detection thereof, and a controller, coupled to the first antenna, the antenna detection circuit and the switch control circuit, configured to receive the first control signal and connect to the second antenna when the first control signal indicates the presence of the second antenna.