Patent ID: 6181199
Filing Date: 2001-01-30
Classification: H03C,H03F,H04L

Abstract:
A power modulation system that modulates and amplifies in-phase (I) and quadrature-phase (Q) input signals, the power modulation system comprising:first and second power amplifiers, each including a signal input, a supply input and a power output;a source of first, second, third and fourth reference frequency signals, the first and second reference frequency signals being inverted relative to one another and the third and fourth reference frequency signals being inverted relative to one another;a switching system that selectively applies one of the first and second reference frequency signals to the signal input of the first power amplifier as a function of the polarity of one of the I and Q input signals, and that selectively applies one of the third and fourth reference frequency signals to the signal input of the second power amplifier as a function of the polarity of the other of the I and Q input signals;a third amplifier that is responsive to the one of the I and Q input signals to supply a first variable supply voltage to the supply input of the first power amplifier;a fourth amplifier that is responsive to the other of the I and Q input signals to supply a second variable supply voltage to the supply input of the second power amplifier; anda coupler that couples the power outputs of the first and second power amplifiers to a load.