High frequency power amplifier control method, for mobile radio terminal, deriving automatic power control voltage from desired power level and value representing difference between antenna directional coupler voltages

摘要

The amplifier (PA) is controlled using an automatic power control voltage (Vapc) generated in a control block (1) receiving inputs representing battery voltage and current, desired output level (E4.1) and actual (E4.2) output level. The latter is derived by determining (7) the difference between forward (E1.4) and reflected (E1.3) voltages generated by two diodes (D1, D2) connected to a directional coupler (K) at the antenna feed point. Preferably the characteristic of an automatic controller (4) within the control block is altered as a function of the power control voltage and a stored reference voltage. Independent claims are included for : (1) a device for controlling a high frequency power amplifier; and (2) a mobile terminal, especially a mobile radio device.