Question:
The LNB gain begins to roll off noticeably after 20.45 GHz, with a significant drop-off toward the upper end of the band. The total gain variation across the band reaches approximately 12 dB between the peak and minimum values.
Is there any configuration or adjustment that can be made directly on the ADMV4420 to help compensate for this gain roll-off?
Answer:
Yes, the ADMV4420 does exhibit gain variation across its frequency range. According to the datasheet, gain typically decreases at the higher end of its supported frequency band.
You do not necessarily need to revise the hardware design at this point. Try:
- Adjusting the ADMV4420 gain via SPI for high-frequency operation.
- Implementing IF equalization in analog or digital domain.
These approaches can help flatten the gain profile and compensate for the roll-off at the high end of the band without a full redesign.