| 主权项 |
1. A dual band transmitter for transmitting a signal in one of a first frequency band and a second frequency band, wherein the dual band transmitter comprises:
an antenna for transmitting and receiving the signal in one of the first and second frequency bands; and an antenna impedance matching network connected in series with the antenna and to a first node, the antenna impedance matching network for matching the impedance of the antenna to a predetermined value; wherein the antenna impedance matching network comprises a first antenna matching network and a second antenna matching network, the first antenna matching network connected in series with the second matching network, wherein the first antenna matching network includes a first capacitor coupled between the first node and ground, a first inductor coupled between the first node and a second node, and a second capacitor coupled between the second node and ground, wherein the second antenna matching network includes a first set of elements including a third capacitor and a second inductor coupled in series between the second node and a third node, and a second set of elements including a third inductor and a fourth capacitor coupled in parallel between the third node and ground, wherein the first and second sets of elements resonant at the frequency in the first frequency band, and wherein in the first frequency band, the first antenna matching network matches the impedance of the antenna to the predetermined value, and in the second frequency band, the second antenna matching network matches the impedance of the antenna to the predetermined value without affecting the matching of the first antenna network in the first frequency band. |
