| 摘要 |
A switching circuit connects transceivers for different frequencies alternatively to a common antenna. The circuit including a plurality of sets, each including a plurality of PIN diodes connected in series, and the PIN diodes in a set may be activated by a DC current, which DC current is led through a bias resistor, creating a bias voltage. This bias voltage is used for reverse biasing the PIN diodes in another set, thus eliminating quiescent PIN diodes therein from creating spurious signals. The circuit is particularly suited for cellular mobile telephones using two frequency bands. |
