Re: Airspy architecture
On 2/2/2015 1:37 PM, 'siegfried jackstien' siegfried.jackstien@... [airspy] wrote:
I would guess the if n and if p means if negative and if positive (balanced output) and NOT be I/Q signals The r820t tuner does only have low if out and not 0hz if (i/q)
Yes, that was also my first guess, but the high image rejection made me wondering... And in any case you can have I/Q outputs also if the IF is not at zero.
On 2/2/2015 3:45 PM, Leif Asbrink leif@... [airspy] wrote:
Hi Leif,The R820T2 has I and Q internally and combines them to a real valued signal with excellent image suppression. The output is balanced to fit the balanced input of typical AD converters. I have no idea how they can get such a good image suppression...
ï¿½ That explains a lot. From the simplified block diagram found on Internet the use
of a quadrature mixer is not apparent, and that made me scraping my head...
Yes, achieving 65 dB of image rejection working in the analog domain is really
a feat... kudos to them... everything must have been balanced with extraordinary
Thanks Sigi and Leif.
73 Alberto I2PHD
Credo Ut Intelligam