Atec Agilent-E4421B-24B-32B-33B-35B-36B - Manual (Page 14)

14
I/Q baseband generator
(continued)
Modulation QPSK π/4DQPSK 16QAM 2FSK GMSK
Filter Root Nyquist Gaussian
Filter factor ( α or BbT) 0.25 0.25 0.25 0.5 0.5
Modulation index N/A N/A N/A 0.5 N/A
Symbol rate (Msym/s) 4 4 4 1 1
Error vector magnitude 1 Shift error 1 Global phase error 1
(% rms) (% rms) (degrees rms)
fc = 1 GHz 1.2 1.2 1.0 0.8 0.4
fc = 2 GHz 1.3 1.3 1.2 0.9 0.4
fc = 3 GHz 1.8 1.9 1.7 1.0 0.6
fc = 4 GHz 3.7 3.6 4.0 1.3 1.0
Baseband EVM performance versus symbol rate
(root Nyquist filter, modulation = QPSK)
RF EVM performance versus symbol rate
(fc = 1 GHz, root Nyquist filter, ALC = off, modulation = QPSK)
RF EVM performance versus frequency
(root Nyquist filter, a = 0.25, ALC = off, modulation =
π/4DQPSK)
Effects of automatic level control (ALC) on EVM performance
(fc = 1 GHz, root Nyquist filter, a = 0.25, modulation = QPSK)
Typcal performance (power levels
≤ + 4 dBm [≤ + 8 dBm, Option UNB])
PSK formats
1. Specifications apply at power levels ≤ +4 dBm, Option (UNB) with default scale factor of I/Q outputs.
Custom digitally modulated signals