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signal ID improved

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This commit is contained in:
Jan Käberich 2020-11-14 23:53:55 +01:00
parent 735e7096f4
commit 3055564a27
4 changed files with 53 additions and 12 deletions
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9
Software/VNA_embedded/Application/VNA.cpp
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@ -11,6 +11,7 @@
#include "Communication.h"
#include "FreeRTOS.h"
#include "task.h"
#include "Util.hpp"
#define LOG_LEVEL LOG_LEVEL_INFO
#define LOG_MODULE "VNA"
@ -304,13 +305,7 @@ void VNA::SweepHalted() {
// Depending on the stimulus frequency, the resulting mixing product might alias to the 2.IF
// in the ADC which causes a spike. Check for this and shift the ADC sampling frequency if necessary
uint32_t LO_mixing = (HW::IF1 + frequency) - (HW::IF1 - HW::IF2);
// move frequency into ADC range
LO_mixing %= HW::ADCSamplerate;
// fold at half the samplerate
if(LO_mixing >= HW::ADCSamplerate / 2) {
LO_mixing = HW::ADCSamplerate - LO_mixing;
}
if(abs(LO_mixing - HW::IF2) <= actualBandwidth * 2) {
if(abs(Util::Alias(LO_mixing, HW::ADCSamplerate) - HW::IF2) <= actualBandwidth * 2) {
// the image is in or near the IF bandwidth and would cause a peak
// Use a slightly different ADC samplerate
adcShiftRequired = true;