LT5528 WCDMA ACPR and AltCPR Measurements - Design Note 375

摘要

ACPR (adjacent channel power ratio) and AltCPR (alternate channel power ratio) are important measures of spectral regrowth for digital communication systems that use, for example, WCDMA (wideband code division multiple access) modulation. Both ACPR and AltCPR quantify the ratio of regrowth in a nearby channel to the power in the transmitted channel. To measure ACPR and AltCPR, refer to the test setup shown in Figure 2. The DUT (device under test) is the LT5528, which is a high linearity direct I/Q modulator. It accepts complex modulation signals at its baseband inputs and generates a modulated RF signal at the RF output.