1 /*
2 * stripline.cpp - stripline class definition
3 *
4 * Copyright (C) 2011 Michael Margraf <michael.margraf@alumni.tu-berlin.de>
5 * Modifications 2018 for Kicad: Jean-Pierre Charras
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or (at
10 * your option) any later version.
11 *
12 * This program is distributed in the hope that it will be useful, but
13 * WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License
18 * along with this package; see the file COPYING. If not, write to
19 * the Free Software Foundation, Inc., 51 Franklin Street - Fifth Floor,
20 * Boston, MA 02110-1301, USA.
21 *
22 */
23
24
25 #include <cmath>
26 #include <cstdio>
27 #include <cstdlib>
28 #include <cstring>
29
30 #include "stripline.h"
31 #include "units.h"
32
STRIPLINE()33 STRIPLINE::STRIPLINE() : TRANSLINE()
34 {
35 m_Name = "StripLine";
36 Init();
37 }
38
39
40 // -------------------------------------------------------------------
41 // calculate characteristic impedance and conductor loss
lineImpedance(double height,double & ac)42 double STRIPLINE::lineImpedance( double height, double& ac )
43 {
44 double ZL;
45 double hmt = height - m_parameters[T_PRM];
46
47 ac = sqrt( m_parameters[FREQUENCY_PRM] / m_parameters[SIGMA_PRM] / 17.2 );
48
49 if( m_parameters[PHYS_WIDTH_PRM] / hmt >= 0.35 )
50 {
51 ZL = m_parameters[PHYS_WIDTH_PRM]
52 + ( 2.0 * height * log( ( 2.0 * height - m_parameters[T_PRM] ) / hmt )
53 - m_parameters[T_PRM] * log( height * height / hmt / hmt - 1.0 ) )
54 / M_PI;
55 ZL = ZF0 * hmt / sqrt( m_parameters[EPSILONR_PRM] ) / 4.0 / ZL;
56
57 ac *= 2.02e-6 * m_parameters[EPSILONR_PRM] * ZL / hmt;
58 ac *= 1.0 + 2.0 * m_parameters[PHYS_WIDTH_PRM] / hmt
59 + ( height + m_parameters[T_PRM] ) / hmt / M_PI
60 * log( 2.0 * height / m_parameters[T_PRM] - 1.0 );
61 }
62 else
63 {
64 double tdw = m_parameters[T_PRM] / m_parameters[PHYS_WIDTH_PRM];
65 if( m_parameters[T_PRM] / m_parameters[PHYS_WIDTH_PRM] > 1.0 )
66 tdw = m_parameters[PHYS_WIDTH_PRM] / m_parameters[T_PRM];
67 double de = 1.0 + tdw / M_PI * ( 1.0 + log( 4.0 * M_PI / tdw ) ) + 0.236 * pow( tdw, 1.65 );
68 if( m_parameters[T_PRM] / m_parameters[PHYS_WIDTH_PRM] > 1.0 )
69 de *= m_parameters[T_PRM] / 2.0;
70 else
71 de *= m_parameters[PHYS_WIDTH_PRM] / 2.0;
72 ZL = ZF0 / 2.0 / M_PI / sqrt( m_parameters[EPSILONR_PRM] )
73 * log( 4.0 * height / M_PI / de );
74
75 ac *= 0.01141 / ZL / de;
76 ac *= de / height + 0.5 + tdw / 2.0 / M_PI + 0.5 / M_PI * log( 4.0 * M_PI / tdw )
77 + 0.1947 * pow( tdw, 0.65 ) - 0.0767 * pow( tdw, 1.65 );
78 }
79
80 return ZL;
81 }
82
83
84 // -------------------------------------------------------------------
calcAnalyze()85 void STRIPLINE::calcAnalyze()
86 {
87 m_parameters[SKIN_DEPTH_PRM] = skin_depth();
88
89 m_parameters[EPSILON_EFF_PRM] = m_parameters[EPSILONR_PRM]; // no dispersion
90
91 double ac1, ac2;
92 double t = m_parameters[T_PRM];
93 double a = m_parameters[STRIPLINE_A_PRM];
94 double h = m_parameters[H_PRM];
95 m_parameters[Z0_PRM] = 2.0
96 / ( 1.0 / lineImpedance( 2.0 * a + t, ac1 )
97 + 1.0 / lineImpedance( 2.0 * ( h - a ) - t, ac2 ) );
98 m_parameters[LOSS_CONDUCTOR_PRM] = m_parameters[PHYS_LEN_PRM] * 0.5 * ( ac1 + ac2 );
99 m_parameters[LOSS_DIELECTRIC_PRM] = 20.0 / log( 10.0 ) * m_parameters[PHYS_LEN_PRM]
100 * ( M_PI / C0 ) * m_parameters[FREQUENCY_PRM]
101 * sqrt( m_parameters[EPSILONR_PRM] )
102 * m_parameters[TAND_PRM];
103
104 m_parameters[ANG_L_PRM] = 2.0 * M_PI * m_parameters[PHYS_LEN_PRM]
105 * sqrt( m_parameters[EPSILONR_PRM] ) * m_parameters[FREQUENCY_PRM]
106 / C0; // in radians
107 }
108
109
showAnalyze()110 void STRIPLINE::showAnalyze()
111 {
112 setProperty( Z0_PRM, m_parameters[Z0_PRM] );
113 setProperty( ANG_L_PRM, m_parameters[ANG_L_PRM] );
114
115 if( !std::isfinite( m_parameters[Z0_PRM] ) || m_parameters[Z0_PRM] < 0 )
116 setErrorLevel( Z0_PRM, TRANSLINE_ERROR );
117
118 if( !std::isfinite( m_parameters[ANG_L_PRM] ) || m_parameters[ANG_L_PRM] < 0 )
119 setErrorLevel( ANG_L_PRM, TRANSLINE_ERROR );
120
121 if( !std::isfinite( m_parameters[PHYS_LEN_PRM] ) || m_parameters[PHYS_LEN_PRM] < 0 )
122 setErrorLevel( PHYS_LEN_PRM, TRANSLINE_WARNING );
123
124 if( !std::isfinite( m_parameters[PHYS_WIDTH_PRM] ) || m_parameters[PHYS_WIDTH_PRM] < 0 )
125 setErrorLevel( PHYS_WIDTH_PRM, TRANSLINE_WARNING );
126
127 if( m_parameters[STRIPLINE_A_PRM] + m_parameters[T_PRM] >= m_parameters[H_PRM] )
128 {
129 setErrorLevel( STRIPLINE_A_PRM, TRANSLINE_WARNING );
130 setErrorLevel( T_PRM, TRANSLINE_WARNING );
131 setErrorLevel( H_PRM, TRANSLINE_WARNING );
132 setErrorLevel( Z0_PRM, TRANSLINE_ERROR );
133 }
134 }
135
showSynthesize()136 void STRIPLINE::showSynthesize()
137 {
138 setProperty( PHYS_LEN_PRM, m_parameters[PHYS_LEN_PRM] );
139 setProperty( PHYS_WIDTH_PRM, m_parameters[PHYS_WIDTH_PRM] );
140
141 if( !std::isfinite( m_parameters[PHYS_LEN_PRM] ) || m_parameters[PHYS_LEN_PRM] < 0 )
142 setErrorLevel( PHYS_LEN_PRM, TRANSLINE_ERROR );
143
144 if( !std::isfinite( m_parameters[PHYS_WIDTH_PRM] ) || m_parameters[PHYS_WIDTH_PRM] < 0 )
145 setErrorLevel( PHYS_WIDTH_PRM, TRANSLINE_ERROR );
146
147 if( !std::isfinite( m_parameters[Z0_PRM] ) || m_parameters[Z0_PRM] < 0 )
148 setErrorLevel( Z0_PRM, TRANSLINE_WARNING );
149
150 if( !std::isfinite( m_parameters[ANG_L_PRM] ) || m_parameters[ANG_L_PRM] < 0 )
151 setErrorLevel( ANG_L_PRM, TRANSLINE_WARNING );
152
153 if( m_parameters[STRIPLINE_A_PRM] + m_parameters[T_PRM] >= m_parameters[H_PRM] )
154 {
155 setErrorLevel( STRIPLINE_A_PRM, TRANSLINE_WARNING );
156 setErrorLevel( T_PRM, TRANSLINE_WARNING );
157 setErrorLevel( H_PRM, TRANSLINE_WARNING );
158 setErrorLevel( PHYS_WIDTH_PRM, TRANSLINE_ERROR );
159 }
160 }
161 // -------------------------------------------------------------------
show_results()162 void STRIPLINE::show_results()
163 {
164
165 setResult( 0, m_parameters[EPSILON_EFF_PRM], "" );
166 setResult( 1, m_parameters[LOSS_CONDUCTOR_PRM], "dB" );
167 setResult( 2, m_parameters[LOSS_DIELECTRIC_PRM], "dB" );
168
169 setResult( 3, m_parameters[SKIN_DEPTH_PRM] / UNIT_MICRON, "µm" );
170 }
171
172
173 #define MAX_ERROR 0.000001
174
175 // -------------------------------------------------------------------
calcSynthesize()176 void STRIPLINE::calcSynthesize()
177 {
178 minimizeZ0Error1D( &( m_parameters[PHYS_WIDTH_PRM] ) );
179 }
180