Qucs-core  0.0.19
ivnoise.cpp
Go to the documentation of this file.
00001 /*
00002  * ivnoise.cpp - correlated noise sources class implementation
00003  *
00004  * Copyright (C) 2005, 2008 Stefan Jahn <stefan@lkcc.org>
00005  *
00006  * This is free software; you can redistribute it and/or modify
00007  * it under the terms of the GNU General Public License as published by
00008  * the Free Software Foundation; either version 2, or (at your option)
00009  * any later version.
00010  *
00011  * This software is distributed in the hope that it will be useful,
00012  * but WITHOUT ANY WARRANTY; without even the implied warranty of
00013  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
00014  * GNU General Public License for more details.
00015  *
00016  * You should have received a copy of the GNU General Public License
00017  * along with this package; see the file COPYING.  If not, write to
00018  * the Free Software Foundation, Inc., 51 Franklin Street - Fifth Floor,
00019  * Boston, MA 02110-1301, USA.
00020  *
00021  * $Id$
00022  *
00023  */
00024 
00025 #if HAVE_CONFIG_H
00026 # include <config.h>
00027 #endif
00028 
00029 #include "component.h"
00030 #include "ivnoise.h"
00031 
00032 #define NODE_I1P 0
00033 #define NODE_I1N 3
00034 #define NODE_V2P 1
00035 #define NODE_V2N 2
00036 
00037 using namespace qucs;
00038 
00039 ivnoise::ivnoise () : circuit (4) {
00040   type = CIR_IVNOISE;
00041   setVoltageSources (1);
00042 }
00043 
00044 void ivnoise::initSP (void) {
00045   allocMatrixS ();
00046   setS (NODE_I1P, NODE_I1P, 1.0);
00047   setS (NODE_I1N, NODE_I1N, 1.0);
00048   setS (NODE_V2P, NODE_V2N, 1.0);
00049   setS (NODE_V2N, NODE_V2P, 1.0);
00050 }
00051 
00052 void ivnoise::calcNoiseSP (nr_double_t frequency) {
00053   nr_double_t C = getPropertyDouble ("C");
00054   nr_double_t e = getPropertyDouble ("e");
00055   nr_double_t c = getPropertyDouble ("c");
00056   nr_double_t a = getPropertyDouble ("a");
00057   nr_double_t k = a + c * qucs::pow (frequency, e);
00058   nr_double_t i1 = getPropertyDouble ("i1") / k / kB / T0;
00059   nr_double_t u2 = getPropertyDouble ("v2") / k / kB / T0;
00060   nr_double_t ci = C * std::sqrt (i1 * u2) / 2;
00061 
00062   // entries of source 1
00063   setN (NODE_I1P, NODE_I1P, +i1 * z0); setN (NODE_I1N, NODE_I1N, +i1 * z0);
00064   setN (NODE_I1P, NODE_I1N, -i1 * z0); setN (NODE_I1N, NODE_I1P, -i1 * z0);
00065   // entries of source 2
00066   setN (NODE_V2P, NODE_V2P, +u2 /4/z0); setN (NODE_V2N, NODE_V2N, +u2 /4/z0);
00067   setN (NODE_V2P, NODE_V2N, -u2 /4/z0); setN (NODE_V2N, NODE_V2P, -u2 /4/z0);
00068   // correlation entries
00069   setN (NODE_I1P, NODE_V2P, +ci); setN (NODE_I1N, NODE_V2N, +ci);
00070   setN (NODE_I1P, NODE_V2N, -ci); setN (NODE_I1N, NODE_V2P, -ci);
00071   setN (NODE_V2P, NODE_I1P, +ci); setN (NODE_V2N, NODE_I1N, +ci);
00072   setN (NODE_V2P, NODE_I1N, -ci); setN (NODE_V2N, NODE_I1P, -ci);
00073 }
00074 
00075 void ivnoise::initDC (void) {
00076   allocMatrixMNA ();
00077   voltageSource (VSRC_1, NODE_V2P, NODE_V2N);
00078 }
00079 
00080 void ivnoise::initAC (void) {
00081   initDC ();
00082 }
00083 
00084 void ivnoise::initTR (void) {
00085   initDC ();
00086 }
00087 
00088 void ivnoise::calcNoiseAC (nr_double_t frequency) {
00089   nr_double_t C = getPropertyDouble ("C");
00090   nr_double_t e = getPropertyDouble ("e");
00091   nr_double_t c = getPropertyDouble ("c");
00092   nr_double_t a = getPropertyDouble ("a");
00093   nr_double_t k = a + c * qucs::pow (frequency, e);
00094   nr_double_t i1 = getPropertyDouble ("i1") / k / kB / T0;
00095   nr_double_t u2 = getPropertyDouble ("v2") / k / kB / T0;
00096   nr_double_t ci = C * std::sqrt (i1 * u2);
00097   setN (NODE_I1P, NODE_I1P, +i1); setN (NODE_I1N, NODE_I1N, +i1);
00098   setN (NODE_I1P, NODE_I1N, -i1); setN (NODE_I1N, NODE_I1P, -i1);
00099   setN (NODE_5, NODE_I1P, ci);
00100   setN (NODE_I1P, NODE_5, ci);
00101   setN (NODE_5, NODE_5, u2);
00102 }
00103 
00104 // properties
00105 PROP_REQ [] = {
00106   { "i1", PROP_REAL, { 1e-6, PROP_NO_STR }, PROP_POS_RANGE },
00107   { "v2", PROP_REAL, { 1e-6, PROP_NO_STR }, PROP_POS_RANGE },
00108   { "C", PROP_REAL, { 0.5, PROP_NO_STR }, PROP_RNGII (-1, 1) },
00109   PROP_NO_PROP };
00110 PROP_OPT [] = {
00111   { "a", PROP_REAL, { 0, PROP_NO_STR }, PROP_POS_RANGE },
00112   { "c", PROP_REAL, { 1, PROP_NO_STR }, PROP_POS_RANGE },
00113   { "e", PROP_REAL, { 0, PROP_NO_STR }, PROP_POS_RANGE },
00114   PROP_NO_PROP };
00115 struct define_t ivnoise::cirdef =
00116   { "IVnoise", 4, PROP_COMPONENT, PROP_NO_SUBSTRATE, PROP_LINEAR, PROP_DEF };