[Hackrf-dev] HackRF-dev Digest, Vol 21, Issue 4

[McDonald, J Douglas]

What I want to know is mat I explained (garbled at first but corrected, this morning).

The idea is to know what the aliasing properties of HackRF are.
That is, say I set it to receive 100 MHz at the center of the bandpass
and set the sample rate at 10 megasamples per second, I&Q. 
10 megasamples per second I&Q says Nyquist frequencies are at += 5 MHz 
from 100 Mhz or 95 and 105 MHz. Isn't that right?

I then send in a signal that sweeps, very slowly, from 80 to 120 MHZ,
constanmt amplitude. When at 94 MHz the signal seen will not be zero,
at 80 MHz it probably will be. I just do the scan and not how many
dB it is down versus frequency and plot that. 

By vary with the RF frequency I am asking this: Apparently HackRF
has a somewhat different internal signal flow at various
frequency bands (as implied by different output powers
for different frequencies, implying similar things for receive.)
Could this difference result in different results(i.e response versus
input frequency)  if I substitute
1 GHz or 2GHZ or 2.4 GHZ or 5GHZ for the "100 MHz" above,
keeping sample rate fixed?

Doug McDonald

-----Original Message-----
From: Michael Ossmann [mailto:mike at ossmann.com] 
Sent: Thursday, September 04, 2014 12:09 PM
To: McDonald, J Douglas
Cc: hackrf-dev at greatscottgadgets.com
Subject: Re: [Hackrf-dev] HackRF-dev Digest, Vol 21, Issue 4

On Thu, Sep 04, 2014 at 04:32:44PM +0000, McDonald, J Douglas wrote:
>
> But the performance (i.e. gain, noise figure, and image response) vs
> frequency 10-6000 MHz is not what I was asking. That was the IF
> response, i.e. for antialiasing knowledge. Does that vary with the RF
> frquency?  That information is VERY useful to everybody.

I have no idea what you mean.