| 摘要 |
<p>Power IQ modulations systems and methods include first and second power amplifiers, each including a signal input, a supply input and a power input. A source of first, second, third and fourth reference frequency signals is also provided. Preferably, the first, second, third and fourth reference frequency signals are 0°, 180°, 90° and 270° phase shifted reference frequency signals, respectively. A switching system 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. The switching system also 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 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 amplifier. A fourth amplifier is responsive to the other of I and Q input signals to supply a second variable supply voltage to the supply input of the second amplifier. A coupler couples the power outputs of the first and second power amplifiers to a load such as a radiotelephone antenna.</p> |
