What about omega or loran and a lot of averaging? A meter is really tight. I think omega is completely shutdown, but loran still exists. Both are pre-GPS nav systems and how they worked might provide your answers. Omega was LF and based on phase.
The thickness of the copper only (not the board), at least near 1 GHz, doesn't have a huge affect on the line impedance. I went straight to the Rogers website and used their calculator for microstrip line and it only made ~1 ohm change. The actual board thickness of course makes a big...
I should say 1/2 oz copper clad vs 1 oz copper clad. There is also rolled vs electrodeposited, which I know affects the surface roughness and maybe loss/glue adhesion. Other things I should be aware of?
No offense meant, but that is really something to have that poor a performance. There is something crazy wrong.
Are you sure your antenna measurement system is working correctly? Sounds like you might be working in an outside environment? Maybe you're getting a multipath which is completely...
The return comes off of clear air, the discontinuities in the atmostpheric density. We just have to average a millions times to extract it (if you only have pico volts, but they are repeatable you can average enough). It works, but could use some real tweaking. I think most weather radars only...
My understanding frustrates me... Thanks for your time.
VG-
We try and find signals down around -160 dBm. There is a lot of averaging, time series and spectra. The noise level is set at the LSB so the angels don't kill us as easily and data processing chops the bigger signals. We are doing...
In the radar I'm working on there are many places for "process gain" (?). We monitor wind speed and typically don't see over 100hz doppler shift. We pulse at 20Khz, we do a 4096 pt fft for each gate. That is just sampling the weather...
Then there is the receive chain, bandpass sample at 60MHz...
Sorry, the boards have different ADC. Pretend the theoretical number of bits doesn't change with sampling rate.
Process Gain: My thought was it it is proportional to the oversampling the ADC is capable of. ie a 100MSPS adc vs a 20MSPS. If you bandpass sample a 5MHz band, you could do 10x...
First, thanks for answering.
Yep, I understand on your statement. Same with the overall system evaluation for SNR and SFDR, but I'm just trying to look at it from the point of intercomparing software defined radio boards. The ADC's have significantly different specs and the boards cost...
I have a clear air radar and I'm trying to figure out the system SNR and SFDR from the ADC specs and the bandpass sampling specifications, including process gain...
Starting from the IF coming into the ADC, it happens at 60MHz, there is a 24MHz BPF and the 12 bit ADC is running at 48MHz. If I...
