Average Power and Envelope Tracking Design
Application Notes
With the advent of LTE, the transmission system in a cellular smartphone must process signals with both a very wide range of average power, to suit the user’s location in the cell, and a high (8 dB) short term peak to average power ratio due to the nature of the LTE signal. Depending on the amplifier technology, the device may have to operate several dB below the level it would be capable of providing with a W-CDMA waveform. This comes at a time when battery capacity is already at a premium, heat dissipation within the handset is based on a budget and frequency coverage of multiple spectrum bands is required.