DIGITAL POWER AMPLIFIER Russian patent published in 2000 - IPC

FIELD: radio engineering, amplification of amplitude and frequency modulated signal. SUBSTANCE: digital power amplifier includes amplitude detector 1 which input is input of digital power amplifier, analog- to-digital converter 2, digital-to-analog converter 3, subtracter 4 whose second input is connected to output of amplitude detector 1, comparator 5. D flip-flop 6, first additional key amplifier 7, adder 8, low-pass filter 9 and load 10, all being connected in series. It also has polarity detector 11 whose output is connected to second input of D flip-flop 6 and phase inverter 12 connected in series, decoder 13 whose inputs are connected to proper outputs of analog-to-digital converter 2. Outputs of n pairs of key amplifiers 14 and second additional key amplifier 15 are connected to corresponding inputs of adder 8. Input of first key amplifier of each pair is linked to output of polarity detector 1. Digital power amplifier incorporates n pairs of controlled keys 16, first key of each pair being interposed between output of polarity detector 11 and output of second key amplifier 14 in each of n pairs of key amplifiers 14 and second key of each pair is connected between output of phase inverter 12 and input of second key amplifier 14 in each of n pairs of key amplifiers 14 and controlling inputs of controlled keys 16 are linked to proper outputs of decoder 13. Additional amplitude detector 17, additional low-pass filter 18 whose input is connected to input of polarity detector 11, 90 degrees phase shifter and former 20 of absolute value connected in series are brought in between input of amplitude detector 1 and second input of comparator 5. Inverter 21 and additional D flip-flop 22 whose second input is linked to output of phase inverter 12 connected in series are inserted between output of comparator 5 and input of second additional key amplifier 15. EFFECT: elimination of nonlinear distortions. 14 dwg