Although one embodiment of front end circuitry is shown, other implementations of front end circuitry are possible. For instance, front end circuitry can include power amplifiers (PAs), low noise amplifiers (LNAs), filters, switches, phase shifters, duplexers, and/or other suitable circuitry for processing RF signals transmitted and/or received from one or more antennas. Example functionalities of a front end include but are not limited to, amplifying signals for transmission, amplifying received signals, filtering signals, switching between different bands, switching between different power modes, switching between transmission and receiving modes, duplexing of signals, multiplexing of signals (for instance, diplexing or triplexing), or some combination thereof.

Accordingly, other implementations of primary front end modules, diversity receive front end modules, antenna selection, and/or antenna tuning can be used.

As shown in FIG. 1, the MLS envelope tracker 9 is used to generate one or more power amplifier supply voltages for power amplifiers used in the mobile device 70 to amplify RF signals for wireless transmission. In the illustrated embodiment, the MLS envelope tracker 9 receives a battery voltage V_BATT from the battery 8, and generates a first power amplifier supply voltage V_PA1 for the first power amplifier 21 and a second power amplifier supply voltage V_PA2 for the first power amplifier 22. Although an example in which the MLS envelope tracker 9 generates two power amplifier supply voltages is shown, the MLS envelope tracker 9 can generate more or fewer power amplifier supply voltages.