| 摘要 |
The bias current of a low noise amplifier (LNA) 22 in the receiver circuit 18 of a transceiver is controlled to a high value by a baseband processor 14 to maintain linearity in the presence of leakage of a signal from the transmitter. As the signal from the transmitter is lowered the bias current is controlled low to maintain efficiency. Figure 3 shows the use of a control voltage converter 62 to derive the bias current control from the transmitter gain control signal. Figure 4 shows the use of a control voltage converter 72 to derive the bias current control from the receiver gain control signal (which has an inverse relation to the transmitter gain control signal). Use in CDMA and TDMA mobile phones is envisaged. |
