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Tracking generator with offset + incomplete automatic source/receiver calibration

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This commit is contained in:
Jan Käberich 2020-11-18 19:19:29 +01:00
parent 026fffd588
commit 5b771e2a86
18 changed files with 517 additions and 51 deletions
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47
Software/VNA_embedded/Application/SpectrumAnalyzer.cpp
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@ -32,6 +32,9 @@ static float port1Measurement[FPGA::DFTbins], port2Measurement[FPGA::DFTbins];
static uint8_t signalIDsteps;
static std::array<uint8_t, 4> signalIDprescalers;
static uint8_t attenuator;
static int64_t trackingFreq;
static bool trackingLowband;
static void StartNextSample() {
uint64_t freq = s.f_start + (s.f_stop - s.f_start) * pointCnt / (points - 1);
@ -50,6 +53,34 @@ static void StartNextSample() {
FPGA::WriteRegister(FPGA::Reg::ADCPrescaler, 112);
FPGA::WriteRegister(FPGA::Reg::PhaseIncrement, 1120);
negativeDFT = true;
// set tracking generator to default values
trackingFreq = 0;
trackingLowband = false;
attenuator = 0;
// this is the first step in each point, update tracking generator if enabled
if (s.trackingGenerator) {
trackingFreq = freq - s.trackingGeneratorOffset;
if(trackingFreq > 0 && trackingFreq <= (int64_t) HW::Info.limits_maxFreq) {
// tracking frequency is valid, calculate required settings and select band
auto amplitude = HW::GetAmplitudeSettings(s.trackingPower, trackingFreq, s.applySourceCorrection, s.trackingGeneratorPort);
attenuator = amplitude.attenuator;
if(trackingFreq < HW::BandSwitchFrequency) {
Si5351.SetCLK(SiChannel::LowbandSource, trackingFreq, Si5351C::PLL::B, amplitude.lowBandPower);
FPGA::Disable(FPGA::Periphery::SourceChip);
FPGA::Disable(FPGA::Periphery::SourceRF);
trackingLowband = true;
} else {
Source.SetFrequency(trackingFreq);
Source.SetPowerOutA(amplitude.highBandPower, true);
FPGA::Enable(FPGA::Periphery::SourceChip);
FPGA::Enable(FPGA::Periphery::SourceRF);
trackingLowband = false;
// selected power potentially changed, update default registers
FPGA::WriteMAX2871Default(Source.GetRegisters());
}
}
}
break;
case 1:
LO2freq = HW::IF1 - HW::IF2;
@ -121,9 +152,9 @@ static void StartNextSample() {
}
// Configure the sampling in the FPGA
FPGA::WriteSweepConfig(0, 0, Source.GetRegisters(), LO1.GetRegisters(), 0,
0, FPGA::SettlingTime::us20, FPGA::Samples::SPPRegister, 0,
FPGA::LowpassFilter::M947);
FPGA::WriteSweepConfig(0, trackingLowband, Source.GetRegisters(), LO1.GetRegisters(), attenuator,
trackingFreq, FPGA::SettlingTime::us20, FPGA::Samples::SPPRegister, 0,
FPGA::LowpassFilter::Auto);
FPGA::StartSweep();
}
@ -162,10 +193,18 @@ void SA::Setup(Protocol::SpectrumAnalyzerSettings settings) {
// enable the required hardware resources
Si5351.Enable(SiChannel::Port1LO2);
Si5351.Enable(SiChannel::Port2LO2);
if (s.trackingGenerator) {
Si5351.Enable(SiChannel::LowbandSource);
} else {
Si5351.Disable(SiChannel::LowbandSource);
}
FPGA::SetWindow((FPGA::Window) s.WindowType);
FPGA::Enable(FPGA::Periphery::LO1Chip);
FPGA::Enable(FPGA::Periphery::LO1RF);
FPGA::Enable(FPGA::Periphery::ExcitePort1);
FPGA::Enable(FPGA::Periphery::ExcitePort1, s.trackingGeneratorPort == 0);
FPGA::Enable(FPGA::Periphery::ExcitePort2, s.trackingGeneratorPort == 1);
FPGA::Enable(FPGA::Periphery::PortSwitch, s.trackingGenerator);
FPGA::Enable(FPGA::Periphery::Amplifier, s.trackingGenerator);
FPGA::Enable(FPGA::Periphery::Port1Mixer);
FPGA::Enable(FPGA::Periphery::Port2Mixer);