Patent ID: 8611835

Claim:
A method for sensing the envelope of high level multi frequency band RF signals in several power amplifiers connected to a common Voltage Enhancement Circuitry (VEC), comprising: a) For each frequency band: a.1) providing an RF transistor operating essentially at a non-linear operating point at said frequency band, said RF transistor being fed by a DC power supply trough an RF filter and terminated by a dummy load that is tuned to said frequency band, for terminating the RF components in the output signal of said RF transistor; a.2) feeding an RF signal of said frequency band into the input of said RF transistors; a.3) obtaining a baseband or IF output signal representing said envelope from the fluctuating current drawn by said RF transistor from said DC power supply during the time period when said RF signal is applied to said input; and b) Combining the video envelope output signals obtained from all RF transistors, each of which being tuned to its corresponding frequency band, to a common output by connecting said video envelope output signals together, such that said common output is essentially equal to the output signal that corresponds to one of the frequency bands; wherein said common output is capable of being used to control the level of enhancement provided by said Voltage Enhancement Circuitry (VEC) to said several power amplifiers.