The base class for all transmission line calculations. More...

#include <transline_calculation_base.h>

Inheritance diagram for TRANSLINE_CALCULATION_BASE:

Public Member Functions
	TRANSLINE_CALCULATION_BASE (std::initializer_list< TRANSLINE_PARAMETERS > aParameters)
	Constructs the transmission line calculation object.

virtual	~TRANSLINE_CALCULATION_BASE ()

void	SetParameter (const TRANSLINE_PARAMETERS aParam, const double aValue)
	Sets the given calculation property.

double	GetParameter (const TRANSLINE_PARAMETERS aParam) const
	Gets the given calculation property.

double &	GetParameterRef (const TRANSLINE_PARAMETERS aParam)
	Adds a constant to the given parameter.

std::unordered_map< TRANSLINE_PARAMETERS, std::pair< double, TRANSLINE_STATUS > > &	GetAnalysisResults ()
	Gets the output parameters following analysis.

std::unordered_map< TRANSLINE_PARAMETERS, std::pair< double, TRANSLINE_STATUS > > &	GetSynthesisResults ()
	Gets the output parameters following synthesis.

virtual void	Analyse ()=0
	Analyses the transmission line using the current parameter set.

virtual bool	Synthesize (SYNTHESIZE_OPTS aOpts)=0
	Synthesis the transmission line using the current parameter set target.

virtual void	SetSynthesizeTarget (TRANSLINE_PARAMETERS aTarget)
	Hint from UI picking which geometry parameter is the unknown when Synthesize is called.

TRANSLINE_PARAMETERS	GetSynthesizeTarget () const
	Returns the parameter that will be solved for during synthesis.

void	UpdateDielectricModel ()
	Refit the Djordjevic-Sarkar model from the current parameter map.

double	GetDispersedEpsilonR (double aF) const
	Dispersed permittivity at aF. Returns raw EPSILONR when the model is inactive.

double	GetDispersedTanDelta (double aF) const
	Dispersed loss tangent at aF. Returns raw TAND when the model is inactive.

virtual double	GetSoldermaskDeltaQ (double, double) const
	Incremental filling factor Delta q_mask representing the fraction of the un-coated above-trace air region that a mask of thickness C displaces when laid on top of the substrate.

std::pair< double, double >	ApplySoldermaskCorrection (double aEpsEffUncoated, double aTanDeltaSubstrate, double aEpsRSubstrate, double aWOverH, double aF) const
	Apply a three-layer (substrate / soldermask / air) correction to an un-coated (eps_eff, tan_delta) pair using the air-replacement decomposition of Bahl and Stuchly 1980, with the mask filling factor computed from Svacina 1992 as improved by Wan and Hoorfar 2000.

Static Public Member Functions
static double	WanHoorfarQ2 (double aU, double aHBarTop)
	Wan-Hoorfar 2000 eq.

Protected Member Functions
void	InitProperties (const std::initializer_list< TRANSLINE_PARAMETERS > &aParams)
	Initialises the properties used (as inputs or outputs) by the calculation.

virtual void	SetAnalysisResults ()=0
	Sets values in the output analysis results structure.

virtual void	SetSynthesisResults ()=0
	Sets values in the output synthesis results structure.

void	SetAnalysisResult (TRANSLINE_PARAMETERS aParam, const double aValue, const TRANSLINE_STATUS aStatus=TRANSLINE_STATUS::OK)
	Sets an analysis result.

void	SetSynthesisResult (TRANSLINE_PARAMETERS aParam, const double aValue, const TRANSLINE_STATUS aStatus=TRANSLINE_STATUS::OK)
	Sets a synthesis result.

bool	MinimiseZ0Error1D (TRANSLINE_PARAMETERS aOptimise, TRANSLINE_PARAMETERS aMeasure, bool aRecalculateLength=false)
	minimizeZ0Error1D

bool	MinimiseZ0Error2D (TRANSLINE_PARAMETERS aParam1, TRANSLINE_PARAMETERS aParam2)
	minimizeZ0Error2D

double	SkinDepth () const
	Calculate skin depth.

Static Protected Member Functions
static double	UnitPropagationDelay (double aEpsilonEff)
	Calculates the unit propagation delay (ps/cm) for the given effective permittivity.

static std::pair< double, double >	EllipticIntegral (double arg)
	Computes the complete elliptic integral of first kind K() and the second kind E() using the arithmetic-geometric mean algorithm (AGM) by Abramowitz and Stegun.

static double	coth (const double x)
	Calculates cosh of the given argument.

static double	sech (const double x)
	Calculates sech of the given argument.

Protected Attributes
std::unordered_map< TRANSLINE_PARAMETERS, double >	m_parameters
	All input and output properties used by the calculation.

std::unordered_map< TRANSLINE_PARAMETERS, std::pair< double, TRANSLINE_STATUS > >	m_analysisStatus
	Analysis results.

std::unordered_map< TRANSLINE_PARAMETERS, std::pair< double, TRANSLINE_STATUS > >	m_synthesisStatus
	Synthesis results.

TRANSLINE_PARAMETERS	m_synthesizeTarget { TRANSLINE_PARAMETERS::UNKNOWN_ID }
	Which geometry parameter is the unknown during synthesis (set by the UI)

std::optional< DIELECTRIC_DJORDJEVIC_SARKAR >	m_dsModel
	Fitted Djordjevic-Sarkar model. Empty unless DIELECTRIC_MODEL_SEL selects it.

Static Protected Attributes
static constexpr double	m_maxError { 0.000001 }
	The maximum error for Z0 optimisations.

Detailed Description

The base class for all transmission line calculations.

This is used by the PCB calculator, and by delay profiles

Definition at line 146 of file transline_calculation_base.h.

Constructor & Destructor Documentation

◆ TRANSLINE_CALCULATION_BASE()

TRANSLINE_CALCULATION_BASE::TRANSLINE_CALCULATION_BASE ( std::initializer_list< TRANSLINE_PARAMETERS > aParameters )

inline

Constructs the transmission line calculation object.

@aParameters all parameters that are used (as inputs or outputs) by the calculation

Definition at line 154 of file transline_calculation_base.h.

References InitProperties().

Referenced by COAX::COAX(), COPLANAR::COPLANAR(), COUPLED_MICROSTRIP::COUPLED_MICROSTRIP(), COUPLED_STRIPLINE::COUPLED_STRIPLINE(), MICROSTRIP::MICROSTRIP(), RECTWAVEGUIDE::RECTWAVEGUIDE(), STRIPLINE::STRIPLINE(), and TWISTEDPAIR::TWISTEDPAIR().

◆ ~TRANSLINE_CALCULATION_BASE()

virtual TRANSLINE_CALCULATION_BASE::~TRANSLINE_CALCULATION_BASE ( )

inlinevirtual

Definition at line 159 of file transline_calculation_base.h.

Member Function Documentation

◆ Analyse()

virtual void TRANSLINE_CALCULATION_BASE::Analyse ( )

pure virtual

Analyses the transmission line using the current parameter set.

Implemented in COAX, COPLANAR, COUPLED_MICROSTRIP, COUPLED_STRIPLINE, MICROSTRIP, RECTWAVEGUIDE, STRIPLINE, and TWISTEDPAIR.

Referenced by MinimiseZ0Error1D().

◆ ApplySoldermaskCorrection()

std::pair< double, double > TRANSLINE_CALCULATION_BASE::ApplySoldermaskCorrection	(	double	aEpsEffUncoated,
		double	aTanDeltaSubstrate,
		double	aEpsRSubstrate,
		double	aWOverH,
		double	aF ) const

Apply a three-layer (substrate / soldermask / air) correction to an un-coated (eps_eff, tan_delta) pair using the air-replacement decomposition of Bahl and Stuchly 1980, with the mask filling factor computed from Svacina 1992 as improved by Wan and Hoorfar 2000.

eps_eff_coated   = eps_eff_uncoated + Delta q_mask * (eps_mask - 1)
tan_delta_coated = [ q_sub * eps_sub * tan_delta_sub
                     + Delta q_mask * eps_mask * tan_delta_mask ] / eps_eff_coated

q_sub is inferred from eps_eff_uncoated using the standard filling factor relation q_sub = (eps_eff_uncoated - 1) / (eps_sub - 1), which is exact to within the quasi- TEM assumption that produces eps_eff in the first place. Returns the inputs unchanged when SOLDERMASK_PRESENT is 0, the mask thickness is 0, the mask parameters are non-physical, or the subclass reports Delta q_mask <= 0. aF is reserved for a future frequency-dependent mask model and currently unused.

Definition at line 274 of file transline_calculation_base.cpp.

References GetParameter(), GetSoldermaskDeltaQ(), H, SOLDERMASK_EPSILONR, SOLDERMASK_PRESENT, SOLDERMASK_TAND, and SOLDERMASK_THICKNESS.

Referenced by COPLANAR::Analyse(), COUPLED_MICROSTRIP::Analyse(), and MICROSTRIP::Analyse().

◆ coth()

static double TRANSLINE_CALCULATION_BASE::coth ( const double x )

inlinestaticprotected

Calculates cosh of the given argument.

Definition at line 328 of file transline_calculation_base.h.

Referenced by COUPLED_STRIPLINE::calcZeroThicknessCoupledImpedances().

◆ EllipticIntegral()

std::pair< double, double > TRANSLINE_CALCULATION_BASE::EllipticIntegral ( double arg )

staticprotected

Computes the complete elliptic integral of first kind K() and the second kind E() using the arithmetic-geometric mean algorithm (AGM) by Abramowitz and Stegun.

Returns: std::pair<K, E> where K = first kind integral, E = second kind integral

Definition at line 340 of file transline_calculation_base.cpp.

Referenced by COPLANAR::Analyse(), COUPLED_STRIPLINE::calcSingleStripImpedances(), and COUPLED_STRIPLINE::calcZeroThicknessCoupledImpedances().

◆ GetAnalysisResults()

std::unordered_map< TRANSLINE_PARAMETERS, std::pair< double, TRANSLINE_STATUS > > & TRANSLINE_CALCULATION_BASE::GetAnalysisResults ( )

Gets the output parameters following analysis.

Definition at line 40 of file transline_calculation_base.cpp.

References m_analysisStatus, and SetAnalysisResults().

◆ GetDispersedEpsilonR()

double TRANSLINE_CALCULATION_BASE::GetDispersedEpsilonR ( double aF ) const

Dispersed permittivity at aF. Returns raw EPSILONR when the model is inactive.

Definition at line 200 of file transline_calculation_base.cpp.

References EPSILONR, GetParameter(), and m_dsModel.

Referenced by COAX::Analyse(), COPLANAR::Analyse(), COUPLED_MICROSTRIP::Analyse(), COUPLED_STRIPLINE::Analyse(), MICROSTRIP::Analyse(), RECTWAVEGUIDE::Analyse(), STRIPLINE::Analyse(), TWISTEDPAIR::Analyse(), BOOST_AUTO_TEST_CASE(), BOOST_AUTO_TEST_CASE(), BOOST_AUTO_TEST_CASE(), COAX::Synthesize(), and RECTWAVEGUIDE::Synthesize().

◆ GetDispersedTanDelta()

double TRANSLINE_CALCULATION_BASE::GetDispersedTanDelta ( double aF ) const

Dispersed loss tangent at aF. Returns raw TAND when the model is inactive.

Definition at line 209 of file transline_calculation_base.cpp.

References GetParameter(), m_dsModel, and TAND.

Referenced by COAX::Analyse(), COPLANAR::Analyse(), COUPLED_MICROSTRIP::Analyse(), COUPLED_STRIPLINE::Analyse(), MICROSTRIP::Analyse(), RECTWAVEGUIDE::Analyse(), STRIPLINE::Analyse(), TWISTEDPAIR::Analyse(), BOOST_AUTO_TEST_CASE(), BOOST_AUTO_TEST_CASE(), BOOST_AUTO_TEST_CASE(), and RECTWAVEGUIDE::Synthesize().

◆ GetParameter()

double TRANSLINE_CALCULATION_BASE::GetParameter ( const TRANSLINE_PARAMETERS aParam ) const

inline

Gets the given calculation property.

Definition at line 165 of file transline_calculation_base.h.

References m_parameters.

◆ GetParameterRef()

double & TRANSLINE_CALCULATION_BASE::GetParameterRef ( const TRANSLINE_PARAMETERS aParam )

inline

Adds a constant to the given parameter.

Definition at line 168 of file transline_calculation_base.h.

References m_parameters.

Referenced by MinimiseZ0Error1D().

◆ GetSoldermaskDeltaQ()

virtual double TRANSLINE_CALCULATION_BASE::GetSoldermaskDeltaQ	(	double	,
		double	) const

inlinevirtual

Incremental filling factor Delta q_mask representing the fraction of the un-coated above-trace air region that a mask of thickness C displaces when laid on top of the substrate.

Default zero means the subclass is not mask-eligible (stripline, coax, rectangular waveguide, twisted pair) and ApplySoldermaskCorrection will return its inputs unchanged. Mask-eligible subclasses (microstrip, coupled microstrip, CPW) override using the Wan-Hoorfar 2000 improved Svacina formula or a CPW-specific empirical form.

Reimplemented in COPLANAR, COUPLED_MICROSTRIP, and MICROSTRIP.

Definition at line 216 of file transline_calculation_base.h.

Referenced by ApplySoldermaskCorrection().

◆ GetSynthesisResults()

std::unordered_map< TRANSLINE_PARAMETERS, std::pair< double, TRANSLINE_STATUS > > & TRANSLINE_CALCULATION_BASE::GetSynthesisResults ( )

Gets the output parameters following synthesis.

Definition at line 48 of file transline_calculation_base.cpp.

References m_synthesisStatus, and SetSynthesisResults().

◆ GetSynthesizeTarget()

TRANSLINE_PARAMETERS TRANSLINE_CALCULATION_BASE::GetSynthesizeTarget ( ) const

inline

Returns the parameter that will be solved for during synthesis.

Definition at line 192 of file transline_calculation_base.h.

References m_synthesizeTarget.

◆ InitProperties()

void TRANSLINE_CALCULATION_BASE::InitProperties ( const std::initializer_list< TRANSLINE_PARAMETERS > & aParams )

protected

Initialises the properties used (as inputs or outputs) by the calculation.

Definition at line 32 of file transline_calculation_base.cpp.

References m_parameters.

Referenced by TRANSLINE_CALCULATION_BASE().

◆ MinimiseZ0Error1D()

bool TRANSLINE_CALCULATION_BASE::MinimiseZ0Error1D	(	TRANSLINE_PARAMETERS	aOptimise,
		TRANSLINE_PARAMETERS	aMeasure,
		bool	aRecalculateLength = false )

protected

minimizeZ0Error1D

Tries to find a parameter that minimizes the error on Z0. This function only works with a single parameter. Calls Analyse several times until the error is acceptable.

This function does not change Z0 / Angl_L

Parameters

aOptimise	Parameter to optimise
aMeasure	The parameter to measure / optimise against
aRecalculateLength	True if the angular length should be recalculated (not for differential pair usage)

Returns: true if error < MAX_ERROR, otherwise false

Definition at line 69 of file transline_calculation_base.cpp.

References Analyse(), ANG_L, TRANSLINE_CALCULATIONS::C0, EPSILON_EFF, FREQUENCY, GetParameter(), GetParameterRef(), m_maxError, M_PI, PHYS_LEN, and SetParameter().

Referenced by COPLANAR::Synthesize(), COUPLED_MICROSTRIP::Synthesize(), COUPLED_STRIPLINE::Synthesize(), MICROSTRIP::Synthesize(), STRIPLINE::Synthesize(), and TWISTEDPAIR::Synthesize().

◆ MinimiseZ0Error2D()

bool TRANSLINE_CALCULATION_BASE::MinimiseZ0Error2D	(	TRANSLINE_PARAMETERS	aParam1,
		TRANSLINE_PARAMETERS	aParam2 )

protected

minimizeZ0Error2D

Tries to find the parameters that minimizes the error on Z_Diff. This function only works with two parameters. Calls Analyse several times until the error is acceptable. While the error is unacceptable, changes slightly the parameter.

This function does not change Z0 / Angl_L

Parameters

aParam1	First parameter to optimise
aParam2	Secpmd parameter to optimise

Returns: true if error < MAX_ERROR, otherwise false

◆ sech()

static double TRANSLINE_CALCULATION_BASE::sech ( const double x )

inlinestaticprotected

Calculates sech of the given argument.

Definition at line 331 of file transline_calculation_base.h.

Referenced by COUPLED_STRIPLINE::calcSingleStripImpedances().

◆ SetAnalysisResult()

void TRANSLINE_CALCULATION_BASE::SetAnalysisResult	(	TRANSLINE_PARAMETERS	aParam,
		const double	aValue,
		const TRANSLINE_STATUS	aStatus = TRANSLINE_STATUS::OK )

protected

Sets an analysis result.

Definition at line 55 of file transline_calculation_base.cpp.

References m_analysisStatus.

Referenced by COUPLED_STRIPLINE::publishResults(), COAX::SetAnalysisResults(), COPLANAR::SetAnalysisResults(), COUPLED_MICROSTRIP::SetAnalysisResults(), MICROSTRIP::SetAnalysisResults(), RECTWAVEGUIDE::SetAnalysisResults(), STRIPLINE::SetAnalysisResults(), and TWISTEDPAIR::SetAnalysisResults().

◆ SetAnalysisResults()

virtual void TRANSLINE_CALCULATION_BASE::SetAnalysisResults ( )

protectedpure virtual

Sets values in the output analysis results structure.

Implemented in COAX, COPLANAR, COUPLED_MICROSTRIP, COUPLED_STRIPLINE, MICROSTRIP, RECTWAVEGUIDE, STRIPLINE, and TWISTEDPAIR.

Referenced by GetAnalysisResults().

◆ SetParameter()

void TRANSLINE_CALCULATION_BASE::SetParameter	(	const TRANSLINE_PARAMETERS	aParam,
		const double	aValue )

inline

Sets the given calculation property.

Definition at line 162 of file transline_calculation_base.h.

References m_parameters.

◆ SetSynthesisResult()

void TRANSLINE_CALCULATION_BASE::SetSynthesisResult	(	TRANSLINE_PARAMETERS	aParam,
		const double	aValue,
		const TRANSLINE_STATUS	aStatus = TRANSLINE_STATUS::OK )

protected

Sets a synthesis result.

Definition at line 62 of file transline_calculation_base.cpp.

References m_synthesisStatus.

Referenced by COUPLED_STRIPLINE::publishResults(), COAX::SetSynthesisResults(), COPLANAR::SetSynthesisResults(), COUPLED_MICROSTRIP::SetSynthesisResults(), MICROSTRIP::SetSynthesisResults(), RECTWAVEGUIDE::SetSynthesisResults(), STRIPLINE::SetSynthesisResults(), and TWISTEDPAIR::SetSynthesisResults().

◆ SetSynthesisResults()

virtual void TRANSLINE_CALCULATION_BASE::SetSynthesisResults ( )

protectedpure virtual

Sets values in the output synthesis results structure.

Implemented in COAX, COPLANAR, COUPLED_MICROSTRIP, COUPLED_STRIPLINE, MICROSTRIP, RECTWAVEGUIDE, STRIPLINE, and TWISTEDPAIR.

References OK.

Referenced by GetSynthesisResults().

◆ SetSynthesizeTarget()

virtual void TRANSLINE_CALCULATION_BASE::SetSynthesizeTarget ( TRANSLINE_PARAMETERS aTarget )

inlinevirtual

Hint from UI picking which geometry parameter is the unknown when Synthesize is called.

Coax picks Din or Dout; coupled stripline picks W or S; rectangular waveguide picks width or height, etc. Subclasses may override to reject unsupported targets; the default implementation simply stores the value.

Reimplemented in COAX, COPLANAR, RECTWAVEGUIDE, and TWISTEDPAIR.

Definition at line 189 of file transline_calculation_base.h.

References m_synthesizeTarget.

◆ SkinDepth()

double TRANSLINE_CALCULATION_BASE::SkinDepth ( ) const

protected

Calculate skin depth.

$\frac{1}{\sqrt{ \pi \cdot f \cdot \mu \cdot \sigma }}$

Definition at line 151 of file transline_calculation_base.cpp.

References FREQUENCY, GetParameter(), M_PI, TRANSLINE_CALCULATIONS::MU0, MURC, and SIGMA.

Referenced by COAX::Analyse(), COPLANAR::Analyse(), COUPLED_STRIPLINE::Analyse(), RECTWAVEGUIDE::Analyse(), STRIPLINE::Analyse(), TWISTEDPAIR::Analyse(), COUPLED_MICROSTRIP::attenuation(), MICROSTRIP::attenuation(), and RECTWAVEGUIDE::Synthesize().

◆ Synthesize()

virtual bool TRANSLINE_CALCULATION_BASE::Synthesize ( SYNTHESIZE_OPTS aOpts )

pure virtual

Synthesis the transmission line using the current parameter set target.

Returns: true if the synthesis converged, otherwise false

Implemented in COAX, COPLANAR, COUPLED_MICROSTRIP, COUPLED_STRIPLINE, MICROSTRIP, RECTWAVEGUIDE, STRIPLINE, and TWISTEDPAIR.

◆ UnitPropagationDelay()

double TRANSLINE_CALCULATION_BASE::UnitPropagationDelay ( double aEpsilonEff )

staticprotected

Calculates the unit propagation delay (ps/cm) for the given effective permittivity.

@aEpsilonEff is the effective permittivity of the material

Definition at line 160 of file transline_calculation_base.cpp.

Referenced by COPLANAR::Analyse(), STRIPLINE::Analyse(), TWISTEDPAIR::Analyse(), COUPLED_STRIPLINE::calcDielectrics(), MICROSTRIP::dispersion(), and COUPLED_MICROSTRIP::er_eff_freq().

◆ UpdateDielectricModel()

void TRANSLINE_CALCULATION_BASE::UpdateDielectricModel ( )

Refit the Djordjevic-Sarkar model from the current parameter map.

Clears the fitted model when DIELECTRIC_MODEL_SEL is CONSTANT or the spec frequency is non-positive so the accessors fall through to the raw EPSILONR / TAND values.

Definition at line 166 of file transline_calculation_base.cpp.

References DIELECTRIC_MODEL_SEL, DJORDJEVIC_SARKAR, EPSILONR, EPSILONR_SPEC_FREQ, DIELECTRIC_DJORDJEVIC_SARKAR::Fit(), GetParameter(), m_dsModel, and TAND.

Referenced by COAX::Analyse(), COPLANAR::Analyse(), COUPLED_MICROSTRIP::Analyse(), COUPLED_STRIPLINE::Analyse(), MICROSTRIP::Analyse(), RECTWAVEGUIDE::Analyse(), STRIPLINE::Analyse(), TWISTEDPAIR::Analyse(), BOOST_AUTO_TEST_CASE(), BOOST_AUTO_TEST_CASE(), BOOST_AUTO_TEST_CASE(), COAX::Synthesize(), and RECTWAVEGUIDE::Synthesize().

◆ WanHoorfarQ2()

double TRANSLINE_CALCULATION_BASE::WanHoorfarQ2	(	double	aU,
		double	aHBarTop )

static

Wan-Hoorfar 2000 eq.

(12) / (13): filling factor q_2 for the second dielectric layer of a multilayer microstrip with normalised strip width aU = w/h and normalised cumulative layer boundary aHBarTop = h_2/h (so aHBarTop = 1 corresponds to the top of the substrate and aHBarTop > 1 means a mask of thickness (aHBarTop - 1) * h sits on top). This is the corrected form valid for any number of layers, replacing Svacina's original eq (3) / (7) which is only correct for two-layer structures.

Definition at line 218 of file transline_calculation_base.cpp.

References correction, and M_PI.

Referenced by BOOST_AUTO_TEST_CASE(), BOOST_AUTO_TEST_CASE(), COPLANAR::GetSoldermaskDeltaQ(), COUPLED_MICROSTRIP::GetSoldermaskDeltaQ(), and MICROSTRIP::GetSoldermaskDeltaQ().