3.2 Anti-alias filters and alias exposure-free mode
The broadband VSA can be configured to be essentially alias-free by using the full rate sampling mode and installing an external lowpass filter on the digitizer input. Use BNC-f to SMA-m and SMA-f to BNC-m adapters to connect the filter’s SMA connectors to the digitizer in case the digitizer has BNC connectors.
Table 3. External lowpass filters
Digitizer model | Cutoff frequency | Filter part number |
U1066A-002 (DC438) | 90 MHz | Mini-circuits BLP/SLP-90 |
U1066A-001 (DC440) | 100 MHz2 | Mini-circuits1 | BLP/SLP-100 |
U1065A (DC252 (2 ch), | 1650 MHz | Mini-circuits1 | SLP-1650 |
DC282 (2 ch)) | | | |
U1065A (DC222, DC252 | 2000 MHz | Mini-circuits1 | SLP-2000 |
(1 ch), DC282 (1ch)) | | | |
1.Mini-Circuits, Inc., 1-800-854-7949, www.minicircuits.com.
2.For the HF input a 300 MHz lowpass filter will avoid aliasing from signals above 300 MHz, but in-band and out-of-band aliasing is still possible since full rate mode is not supported with the HF input.
