105 lines
4.1 KiB
C++

/*
* Copyright The KiCad Developers, see AUTHORS.txt for contributors.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this package; see the file COPYING. If not, write to
* the Free Software Foundation, Inc., 51 Franklin Street - Fifth Floor,
* Boston, MA 02110-1301, USA.
*/
#ifndef TRANSLINE_CALCULATIONS_COUPLED_STRIPLINE_H
#define TRANSLINE_CALCULATIONS_COUPLED_STRIPLINE_H
#include <transline_calculations/transline_calculation_base.h>
#include <transline_calculations/stripline.h>
/*
* This implements the calculations described in:
*
* [1] S. B. Cohn, "Characteristic Impedance of the Shielded-Strip Transmission Line," in Transactions of the IRE
* Professional Group on Microwave Theory and Techniques, vol. 2, no. 2, pp. 52-57, July 1954
* [2] S. B. Cohn, "Shielded Coupled-Strip Transmission Line," in IRE Transactions on Microwave Theory and Techniques,
* vol. 3, no. 5, pp. 29-38, October 1955
*/
class COUPLED_STRIPLINE : public TRANSLINE_CALCULATION_BASE
{
using TCP = TRANSLINE_PARAMETERS;
public:
COUPLED_STRIPLINE() :
TRANSLINE_CALCULATION_BASE( { TCP::SKIN_DEPTH, TCP::Z0_E, TCP::Z0_O, TCP::Z_DIFF, TCP::PHYS_WIDTH,
TCP::FREQUENCY, TCP::PHYS_LEN, TCP::H, TCP::PHYS_S, TCP::T, TCP::EPSILONR,
TCP::MURC, TCP::SIGMA, TCP::ANG_L } )
{
}
/// Analyse track geometry parameters to output Z0 and Ang_L
void Analyse() override;
/// Synthesis track geometry parameters to match given Z0
bool Synthesize( SYNTHESIZE_OPTS aOpts ) override;
private:
/// Sets the output values and status following analysis
void SetAnalysisResults() override;
/// Sets the output values and status following synthesis
void SetSynthesisResults() override;
/// Calculates the impedance of a finite-width single strip
double calcZ0SymmetricStripline();
/// Calculate the coupling fringe capacitances
void calcFringeCapacitances( double h, double t, double er );
/// Calculates impedances of finite- and zero-thickness single strips
void calcSingleStripImpedances();
/// Calculates zero-thickness coupled strip impedances
void calcZeroThicknessCoupledImpedances( double h, double w, double s, double er );
/// Calculates even mode Z0
void calcZ0EvenMode();
/// Calculates odd mode Z0
void calcZ0OddMode( double t, double s );
/// Calculates conductor and dielectric losses
void calcLosses();
/// Calculate dialectric and propagation parameters
void calcDielectrics();
double C_f_0{ 0.0 }; ///< Fringing capacitance from one edge to ground of zero thickness strip
double C_f_t_h{ 0.0 }; ///< Fringing capacitance of single strip of finite width
double Z0_w_h_0{ 0.0 }; ///< Impedance of single strip of zero thickness
double Z0_w_h_t_h{ 0.0 }; ///< Impedance of single strip of finite thickness
double Z0_e_w_h_0_s_h{ 0.0 }; ///< Even mode impedance of coupled zero thickness strips
double Z0_o_w_h_0_s_h{ 0.0 }; ///< Odd mode impedance of coupled zero thickness strips
double e_eff_e{ 0.0 }; ///< Even mode effective dielectric constant
double e_eff_o{ 0.0 }; ///< Odd mode effective dielectric constant
double ang_l{ 0.0 }; ///< Angular length (rad)
double unit_prop_delay_e{ 0.0 }; ///< Even mode unit propagation delay (ps/cm)
double unit_prop_delay_o{ 0.0 }; ///< Odd mode unit propagation delay (ps/cm)
/// Calculator used to determine single stripline values
STRIPLINE m_striplineCalc;
};
#endif //TRANSLINE_CALCULATIONS_COUPLED_STRIPLINE_H