Broadband envelope tracking

The invention discloses broadband envelope tracking. An envelope tracking scheme can be used, such as to modulate a supply node of a power amplifier circuit to improve efficiency. For example, a magnitude or amplitude envelope of a signal to be modulated can be scaled and used to drive a node, such as a drain, of the power amplifier circuit. An envelope tracking signal can be generated such as having a bandwidth that is compressed as compared to a full-bandwidth envelope signal. A peak-value 'look ahead' technique can be used, for example, so that amplitude compression or clipping of the transmit signal is suppressed when the bandwidth-compressed envelope tracking signal is used to modulate a supply node of the power amplifier used to amplify the transmit signal. 本发明公开宽带包络跟踪。可以使用包络跟踪方案，诸如调制功率放大器电路的电源节点从而改进效率。例如，待调制信号的量值或振幅包络可以被缩放且用于驱动功率放大器电路的节点，诸如漏极。包络跟踪信号可以被生成为例如具有与全带宽包络信号相比被压缩的带宽。可以使用峰值"前瞻"技术，例如，使得当带宽压缩包络跟踪信号用于调制用来放大传输信号的功率放大器的电源节点时抑制传输信号的振幅压缩或限幅。