| 摘要 |
<p>Amplifier-induced intermodulation distortion (IMD) is reduced by encoding (2) a multi-frequency input composite signal into multiple encoded signals that vary from each other in their power amplitudes as a function of frequency, amplifying (6) the encoded signals, and then decoding (4) them in a complementary fashion so as to differentiate between the amplified signal components and the IMD components. The amplified signal components are coherently combined (26) to separate them from the IMD components, which are incoherently combined. The input signal is preferably encoded by dividing it into multiple divided signals (8), introducing relative phase shifts between the divided signals that vary as a function of frequency, and combining the divided and phase shifted signals with each other in a Butler matrix (22) prior to amplification. The phase shifts are introduced by means of time delays (14a, 14b,14c,14N) that are preferably equal to integer multiples of 4 pi divided by the input signal bandwidth. <IMAGE></p> |
