Twisted-pair transmission line calculation. More...

#include <twistedpair.h>

Inheritance diagram for TWISTEDPAIR:

Public Member Functions
	TWISTEDPAIR ()

void	Analyse () override
	Analyse pair geometry to output Z0, electrical length, losses, skin depth, εeff.

bool	Synthesize (SYNTHESIZE_OPTS aOpts) override
	Synthesize Din or Dout to hit the target Z0. Length is recomputed from ANG_L.

void	SetSynthesizeTarget (TRANSLINE_PARAMETERS aTarget) override
	Choose which geometry parameter will be solved for during synthesis.

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.

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.

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.

Private Types
using	TCP = TRANSLINE_PARAMETERS

Private Member Functions
void	SetAnalysisResults () override
	Sets the output values and status following analysis.

void	SetSynthesisResults () override
	Sets the output values and status following synthesis.

Detailed Description

Twisted-pair transmission line calculation.

Implements the Lefferson 1971 closed-form model: pitch angle θ = atan(T·π·Dout), effective permittivity εeff = εr_env + (0.25 + 0.0007·θ²)·(εr − εr_env), and characteristic impedance Z0 = (ZF0/π)·cosh⁻¹(Dout/Din)/√εeff. The reported Z0 is the differential impedance of the pair because Lefferson's model is inherently a two-wire model. Loss is skin-effect conductor loss plus standard tan δ dielectric loss.

Synthesis uses 1-D Newton iteration on either PHYS_DIAM_IN or PHYS_DIAM_OUT to hit a target Z0. The UI picks which diameter is the unknown via SetSynthesizeTarget; the default matches the legacy behaviour and solves for PHYS_DIAM_OUT.

Reference: P. Lefferson, "Twisted Magnet Wire Transmission Line", IEEE Transactions on Parts, Hybrids, and Packaging, vol. PHP-7, no. 4, pp. 148-154, Dec. 1971.

Definition at line 45 of file common/transline_calculations/twistedpair.h.

Member Typedef Documentation

◆ TCP

using TWISTEDPAIR::TCP = TRANSLINE_PARAMETERS

private

Definition at line 47 of file common/transline_calculations/twistedpair.h.

Constructor & Destructor Documentation

◆ TWISTEDPAIR()

TWISTEDPAIR::TWISTEDPAIR ( )

inline

Definition at line 50 of file common/transline_calculations/twistedpair.h.

References ANG_L, DIELECTRIC_MODEL_SEL, EPSILON_EFF, EPSILONR, EPSILONR_SPEC_FREQ, FREQUENCY, LOSS_CONDUCTOR, LOSS_DIELECTRIC, MURC, PHYS_DIAM_IN, PHYS_DIAM_OUT, PHYS_LEN, SIGMA, SKIN_DEPTH, TAND, TRANSLINE_CALCULATION_BASE::TRANSLINE_CALCULATION_BASE(), TWISTEDPAIR_EPSILONR_ENV, TWISTEDPAIR_TWIST, UNIT_PROP_DELAY, and Z0.

Member Function Documentation

◆ Analyse()

void TWISTEDPAIR::Analyse ( )

overridevirtual

Analyse pair geometry to output Z0, electrical length, losses, skin depth, εeff.

$\theta = \arctan\left( T \cdot \pi \cdot D_{out} \right)$

Where :

$\theta$ : pitch angle
: Number of twists per unit length
$D_{out}$ : Wire diameter with insulation

$e_{eff} = e_{env} + \left( 0.25 + 0.0007 \cdot \theta^2 \right)\cdot\left(e_r-e_{env}\right)$

Where :

$e_{env}$ : relative dielectric constant of air (or some other surrounding material)
: relative dielectric constant of the film insulation
$e_{eff}$ : effective relative dielectric constant

$Z_0 = \frac{Z_\mathrm{VACUUM}}{\pi \cdot \sqrt{e_{eff}}}\cosh^{-1}\left(\frac{D_{out}}{D_{in}}\right)$
: differential line impedance
$Z_\mathrm{VACUUM}$ : vacuum impedance
$D_{in}$ : Wire diameter without insulation

Reference: P. Lefferson, "Twisted Magnet Wire Transmission Line", IEEE Transactions on Parts, Hybrids, and Packaging, vol. PHP-7, no. 4, pp. 148-154, Dec. 1971. Twist angle from Fig. 2 caption: T = tan(theta)/(pi*D). Z0 from eq. (1) and Fig. 1 caption (cosh^-1 form, 120/sqrt(eps_req) coefficient). epsEff from eq. (3) combined with the empirical fit in eq. (7) (polyester film, beta = 0.25 + 4e-4*theta^2) and eq. (8) (Teflon, beta = 0.25 + 1e-3*theta^2). KiCad uses a mid-range coefficient 7e-4 that approximates typical magnet-wire insulation.

Implements TRANSLINE_CALCULATION_BASE.

Definition at line 59 of file common/transline_calculations/twistedpair.cpp.

Referenced by BOOST_AUTO_TEST_CASE(), BOOST_AUTO_TEST_CASE(), BOOST_AUTO_TEST_CASE(), BOOST_AUTO_TEST_CASE(), BOOST_AUTO_TEST_CASE(), and BOOST_AUTO_TEST_CASE().

◆ ApplySoldermaskCorrection()

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

inherited

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 )

inlinestaticprotectedinherited

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 )

staticprotectedinherited

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 ( )

inherited

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

inherited

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

inherited

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

inlineinherited

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 )

inlineinherited

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

inlinevirtualinherited

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 ( )

inherited

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

inlineinherited

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 )

protectedinherited

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 )

protectedinherited

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 )

protectedinherited

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 )

inlinestaticprotectedinherited

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 )

protectedinherited

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()

void TWISTEDPAIR::SetAnalysisResults ( )

overrideprivatevirtual

Sets the output values and status following analysis.

Implements TRANSLINE_CALCULATION_BASE.

Definition at line 117 of file common/transline_calculations/twistedpair.cpp.

References ANG_L, EPSILON_EFF, TRANSLINE_CALCULATION_BASE::GetParameter(), LOSS_CONDUCTOR, LOSS_DIELECTRIC, OK, PHYS_DIAM_IN, PHYS_DIAM_OUT, PHYS_LEN, TRANSLINE_CALCULATION_BASE::SetAnalysisResult(), SKIN_DEPTH, TS_ERROR, WARNING, and Z0.

◆ SetParameter()

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

inlineinherited

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 )

protectedinherited

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()

void TWISTEDPAIR::SetSynthesisResults ( )

overrideprivatevirtual

Sets the output values and status following synthesis.

Implements TRANSLINE_CALCULATION_BASE.

Definition at line 147 of file common/transline_calculations/twistedpair.cpp.

References ANG_L, EPSILON_EFF, TRANSLINE_CALCULATION_BASE::GetParameter(), LOSS_CONDUCTOR, LOSS_DIELECTRIC, TRANSLINE_CALCULATION_BASE::m_synthesizeTarget, OK, PHYS_DIAM_IN, PHYS_DIAM_OUT, PHYS_LEN, TRANSLINE_CALCULATION_BASE::SetSynthesisResult(), SKIN_DEPTH, TS_ERROR, WARNING, and Z0.

◆ SetSynthesizeTarget()

void TWISTEDPAIR::SetSynthesizeTarget ( TRANSLINE_PARAMETERS aTarget )

inlineoverridevirtual

Choose which geometry parameter will be solved for during synthesis.

Accepts PHYS_DIAM_IN or PHYS_DIAM_OUT. Any other value is ignored.

Reimplemented from TRANSLINE_CALCULATION_BASE.

Definition at line 73 of file common/transline_calculations/twistedpair.h.

References TRANSLINE_CALCULATION_BASE::m_synthesizeTarget, PHYS_DIAM_IN, and PHYS_DIAM_OUT.

Referenced by BOOST_AUTO_TEST_CASE().

◆ SkinDepth()

double TRANSLINE_CALCULATION_BASE::SkinDepth ( ) const

protectedinherited

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()

bool TWISTEDPAIR::Synthesize ( SYNTHESIZE_OPTS aOpts )

overridevirtual

Synthesize Din or Dout to hit the target Z0. Length is recomputed from ANG_L.

Implements TRANSLINE_CALCULATION_BASE.

Definition at line 104 of file common/transline_calculations/twistedpair.cpp.

References TRANSLINE_CALCULATION_BASE::m_synthesizeTarget, TRANSLINE_CALCULATION_BASE::MinimiseZ0Error1D(), PHYS_DIAM_IN, PHYS_DIAM_OUT, and Z0.

Referenced by BOOST_AUTO_TEST_CASE(), and BOOST_AUTO_TEST_CASE().

◆ UnitPropagationDelay()

double TRANSLINE_CALCULATION_BASE::UnitPropagationDelay ( double aEpsilonEff )

staticprotectedinherited

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 ( )

inherited

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 )

staticinherited

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().