Discontinuing hardware we spent months of full time effort on is a difficult choice. Unfortunately, the Granita chip has a long list of open issues:
- Weaker than specified I/Q LPF, where a 20 MHz setting results in a 80 MHz -3 dB bandwidth.
- Random 45 degrees phase error in one of the two I/Q branches depending on LO frequency
- No operation at the specified 7.2 GHz frequency, VCO voltage overclock required for operation between 5 and 6.3 GHz.
- Harmonics of clk/4 being generated inside the chip.
In addition to the issues themselves, it has also become impossible to talk to Actric Semi. Emails go unanswered, including invites to visit in person. Their last communication (following 20 days of silence) was on the 9th of August, promising they would test the daughterboard during the following week. Nothing since.
For those reasons, we are discontinuing the daughterboard and refunding existing preorders:
- If you only ordered Granita as a RF daughterboard, the entire order amount is being refunded to your card.
- If you ordered multiple RF daughterboards, such as Lime, only the Granita daughterboard is being refunded.
We are open to re-evaluting an Actric Semi daughterboard if those issues are ever addressed, and are looking at alternatives in the meanwhile.
We are sorry for the inconvenience.