Measuring Spread Spectrum and Multitone Signals
CDMA Signal Measurements
Figure 6 and Figure 7 show typical results obtained when measuring a CDMA signal. In these examples, the error is determined by measuring the source at the amplitude of interest, with and without CDMA modulation, adding attenuation until the difference between the two values stops changing. The CW sensor in Figure 6 uses correction factors to correct for power levels beyond its square law operating region.
|
|
| 1.2 |
|
|
|
|
|
| 1 |
|
|
|
|
|
| 0.8 |
|
|
|
(dB) |
|
| 6 |
|
|
|
|
|
|
|
|
| |
Error |
|
| 0.4 |
|
|
|
|
| 0.2 |
|
|
| |
|
|
|
|
|
| |
|
|
| 0 |
|
|
|
0 | 10 | 20 | 30 | |||
|
|
| 0.2 |
|
|
|
|
| Power (dBm) |
|
|
| |
Lower Range Error 
Upper Range Error
CW Sensor Error
Figure 6 Wideband CDMA Error of Agilent E-series E9300 power sensor versus corrected CW sensor
|
|
| 0.1 |
|
|
|
|
|
|
| 0.05 |
|
|
|
|
(dB) | 0 | 0 | 10 | 20 | 30 | ||
Error |
|
|
|
|
|
| |
|
|
|
|
|
| ||
Modulation |
|
|
|
|
|
| |
|
|
|
|
|
| ||
|
|
|
|
|
| ||
|
| Power (dBm) |
|
|
| ||
Lower Range Error 
Upper Range Error
Figure 7 CDMA (IS-95A): 9Ch Fwd
23
