| 摘要 |
<p>The switch attenuator of the invention includes: a first terminal connected to an antenna; a second terminal connected to a transmitter; and a third terminal connected to a receiver, thereby switching a first state and a second state. In the first state, the first terminal is connected to the second terminal; the first terminal is electrically isolated from the third terminal, the third terminal is connected to a ground and the switch attenuator is electrically controllable so as to vary an attenuation amount between the first terminal and the second terminal, while maintaining such a relationship that an impedance Z1 viewed from the first terminal is substantially equal to an impedance Z2 viewed from the second terminal, and in the second state, the first terminal is connected to the third terminal, the first terminal is electrically isolated from the second terminal, the second terminal is connected to a ground and the switch attenuator is electrically controllable so as to vary an attenuation amount between the first terminal and the third terminal, while maintaining such a relationship that the impedance Z1 viewed from the first terminal is substantially equal to an impedance Z3 viewed from the third terminal. <IMAGE></p> |
