/* * capq.cpp - Lossy capacitor class implementation * * Copyright (C) 2015 Andres Martinez-Mera * * This 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, or (at your option) * any later version. * * This software 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. * * $Id$ * */ #if HAVE_CONFIG_H # include #endif #include "component.h" #include "capq.h" #include "iostream" using namespace qucs; //-------------------------------------------------------- // References: // [1] Bahl. Lumped elements for RF and microwave circuits. Pg 167 capq::capq () : circuit (2) { type = CIR_CAPQ; } void capq::calcYp (nr_double_t frequency) { nr_double_t C = getPropertyDouble ("C"); nr_double_t Q = getPropertyDouble ("Q"); nr_double_t f = getPropertyDouble ("f"); nr_double_t Bc = 2.*pi*frequency*C; nr_double_t Gp = 0; if ((f!=0) && (Q!=0) && (frequency!=0)) // Q=0 or f=0 can be used to force ideal behavior (no losses) { nr_double_t Qf=Q; if (!strcmp (getPropertyString ("Mode"), "Linear")) Qf*=frequency/f; if (!strcmp (getPropertyString ("Mode"), "SquareRoot"))Qf*=qucs::sqrt(frequency/f); Gp = Bc / Qf; } Yp = nr_complex_t (Gp, Bc); } //------------------------------------------------------------------ // This function calculates the S-parameters matrix of a lossy capacitor // Q = 1 / (2*pi*f*Rs*C) where Rs is the series resistance and C the capacitance or also // Q = 2*pi*f*C*Gp where Gp is the parallel conductance void capq::calcSP (nr_double_t frequency) { calcYp(frequency); nr_complex_t y = 2.0 * z0 * Yp; setS (NODE_1, NODE_1, 1.0 / (1.0 + y)); setS (NODE_2, NODE_2, 1.0 / (1.0 + y)); setS (NODE_1, NODE_2, y / (1.0 + y)); setS (NODE_2, NODE_1, y / (1.0 + y)); } void capq::calcNoiseSP (nr_double_t) { // calculate noise using Bosma's theorem nr_double_t T = getPropertyDouble ("Temp"); matrix s = getMatrixS (); matrix e = eye (getSize ()); setMatrixN (celsius2kelvin (T) / T0 * (e - s * transpose (conj (s)))); } void capq::initDC (void) { allocMatrixMNA (); // open circuit clearY (); } void capq::initAC (void) { setVoltageSources (0); allocMatrixMNA (); } void capq::initSP(void) { allocMatrixS (); } void capq::calcAC (nr_double_t frequency) { calcYp(frequency); nr_complex_t y11 = Yp; nr_complex_t y12 = -Yp; nr_complex_t y21 = -Yp; nr_complex_t y22 = Yp; setY (NODE_1, NODE_1, y11); setY (NODE_2, NODE_2, y22); setY (NODE_1, NODE_2, y12); setY (NODE_2, NODE_1, y21); } void capq::calcNoiseAC (nr_double_t) { // calculate noise using Bosma's theorem nr_double_t T = getPropertyDouble ("Temp"); setMatrixN (4 * celsius2kelvin (T) / T0 * real (getMatrixY ())); } // properties PROP_REQ [] = { { "C", PROP_REAL, { 1e-12, PROP_NO_STR }, PROP_POS_RANGE }, { "Q", PROP_REAL, { 100, PROP_NO_STR }, PROP_POS_RANGE }, { "f", PROP_REAL, { 100e6, PROP_NO_STR }, PROP_NO_RANGE }, { "Mode", PROP_STR, { PROP_NO_VAL, "Linear" }, PROP_RNG_STR3 ("Linear", "SquareRoot", "Constant") }, PROP_NO_PROP }; PROP_OPT [] = { { "Temp", PROP_REAL, { 26.85, PROP_NO_STR }, PROP_MIN_VAL (K) }, PROP_NO_PROP }; struct define_t capq::cirdef = { "CAPQ", 2, PROP_COMPONENT, PROP_NO_SUBSTRATE, PROP_LINEAR, PROP_DEF };