new command wrs2p

ChangeLog

@@ -1,3 +1,9 @@
+2010-10-15  Holger Vogt
+ * examples/control_structs/s-param.cir new example
+ * commands.c, postcoms.h, postcoms.c, rawfile.h, rawfile.c
+   fteext.h: new command wrs2p, write a s-parameter file 
+   using Touchstone vers. 1 format.
+
 2010-10-15  Holger Vogt
  * src/ciderlib/input/output.c : #include "../misc/tilde.h"
  * inpcom.c: line 2800ff, allow -.5 token

examples/control_structs/s-param.cir

@@ -0,0 +1,116 @@
+Test for Scattering Parameters
+** Two ports
+** Examples: Bipolar,  Tschebyschef, RC
+
+.param Rbase=50 Vbias_in=0 Vbias_out=0
+
+*** The two-port circuit: 
+** port 1: in 0
+** port 2: out 0
+** Bias on both ports through resistor Rbase (to obtain operating point)
+
+** Example RF Bipolar mrf5711
+** VCE 1 V, IE = 5mA
+** QXXXXXXX nc nb ne
+** model obtained from
+** http://141.69.160.32/~krausg/Spice_Model_CD/Vendor%20List/Motorola/Spice/RFBJT/
+*.include MRF5711.lib
+*XMRF5711 out in e  MRF5711
+*Ie e 0 5m
+*Ce e 0 1
+
+** Example Tschebyschef Low Pass filter
+C1 in 0 33.2p
+L1 in 2 99.2n
+C2 2 0 57.2p
+L2 2 out 99.2n
+C3 out 0 33.2p
+
+** Example RC
+** see
+** http://www.allenhollister.com/allen/files/scatteringparameters.pdf
+*R2 in out 10
+*C1 out int5 30p
+*R1 int5 0 10
+
+*** End of circuit
+
+
+** The following subcircuit to be changed only by an experienced user!
+
+*** Driver and readout
+X1 in out S22 S12 S_PARAM
+
+.SUBCKT S_PARAM 22 66 5 7
+* Resistors emulate switches with Ron=0.001 and Roff=1e12
+* to switch driver to input and readout to output (and vice versa, see below)
+RS1 22 2 0.001
+RS2 66 6 0.001
+RS3 22 6 1e12
+RS4 66 2 1e12
+*Driver
+Vacdc 1 0 DC 'Vbias_in' AC 1 $ ac voltage and dc bias at input (applied through load resistor)
+R1 1 2 'Rbase'
+E1 3 0 2 0 2       $ amplify in port ac voltage by 2
+Vac 3 4 DC 0 AC 1  $ subtract driving ac voltage
+R_loop 4 5 0.001
+R3 5 0 1           $ ground return for measure node 5
+*Readout
+E2 7 0 6 0 2       $ amplify out port ac voltage by 2
+R4 6 8 'Rbase'     $ load resistor at output (ac)
+Vdc 8 0 DC 'Vbias_out' AC 0 $ dc bias at output (applied through load resistor)
+.ends
+
+** Check the two ac lines below for being equal!
+.control
+set noaskquit
+set filetype=ascii
+** measurement for s11 and s21
+op
+** save bias voltages to vector
+let Vdcnew=V(X1.1) $ former Vacdc 
+let Vacdcnew=v(X1.8) $ former Vdc 
+*ac lin 20 0.1G 2G $ use for bip transistor
+ac lin 100 2.5MEG 250MEG $ use for Tschebyschef 
+*ac lin 101 1k 10G $ use for RC 
+** switch input and output
+alter R.X1.RS1=1e12
+alter R.X1.RS2=1e12
+alter R.X1.RS3=0.001
+alter R.X1.RS4=0.001
+** switch bias voltages between in and out
+alter V.X1.Vacdc DC=op1.Vacdcnew
+alter V.X1.Vdc DC=op1.Vdcnew
+** measurement for s12 and s22
+op
+*ac lin 20 0.1G 2G $ use for bip transistor
+ac lin 100 2.5MEG 250MEG $ use for Tschebyschef 
+*ac lin 101 1 10G $ use for RC 
+let s11=ac1.s22
+let s21=ac1.s12
+settype s-param S11 S21 S22 S12
+
+let S11db = db(s11)
+let S12db = db(s12)
+let S21db = db(s21)
+let S22db = db(s22)
+settype decibel S11db S21db S22db S12db
+
+let P11=180*ph(s11)/pi
+let P21=180*ph(s21)/pi
+let P22=180*ph(S22)/pi
+let P12=180*ph(S12)/pi
+settype phase P11 P21 P22 P12
+
+let Rbase=@R.X1.R4[Resistance]
+settype impedance Rbase
+
+*plot s11db s21db S22db S12db ylimit -50 0 xlog $ used with RC 
+plot s11db s21db S22db S12db ylimit -0.5 0 $ used with Tschebyschef  
+plot P11 P21 P22 P12
+plot smithgrid S11 S12
+*wrdata s3046 mag(S11) P11 mag(S21) P21 mag(S22) P22 mag(S12) P12 $ write simple table
+wrs2p s3046.s2p $ write touchstone vers. 1 file s3046.s2p
+.endc
+
+.end

src/frontend/commands.c

@@ -71,29 +71,18 @@
 /* gtri - end - wbk - add include files */
 #endif
 
-/* Information about spice commands (strucct comm). */
-    /* The name of the command. */
-//    char *co_comname;
-    /* The function that handles the command. */
-//    void (*co_func) (wordlist *wl);
-    /* These can't be used from nutmeg. */
-//    bool co_spiceonly;
-    /* Is this a "major" command? */
-//    bool co_major;
-    /* Bitmasks for command completion. */
-//    long co_cctypes[4];
-    /* print help message on this environment mask */
-//    unsigned int co_env;
-    /* minimum number of arguments required */
-//    int co_minargs;
-    /* maximum number of arguments allowed */
-//    int co_maxargs;
-    /* The fn that prompts the user. */
-//    void (*co_argfn) (wordlist *wl, struct comm *command);
-    /* When these are printed, printf(string, av[0]) .. */
-//    char *co_help;  
-
-/* Bool fields: spiceonly, major */
+/* Information about spice commands (struct comm). */
+    
+// char *co_comname;  /* The name of the command. */
+// void (*co_func) (wordlist *wl);  /* The function that handles the command. */
+// bool co_spiceonly;  /* These can't be used from nutmeg. */
+// bool co_major; /* Is this a "major" command? */
+// long co_cctypes[4]; /* Bitmasks for command completion. */
+// unsigned int co_env; /* print help message on this environment mask */
+// int co_minargs; /* minimum number of arguments required */
+// int co_maxargs; /* maximum number of arguments allowed */
+// void (*co_argfn) (wordlist *wl, struct comm *command); /* The fn that prompts the user. */
+// char *co_help;  /* When these are printed, printf(string, av[0]) .. */
 
 struct comm spcp_coms[] = {
     { "let", com_let, FALSE, TRUE,
@@ -189,6 +178,10 @@ struct comm spcp_coms[] = {
       { 1, 041000, 041000, 041000 }, E_DEFHMASK, 2, LOTS,
       NULL,
       "file plotargs : Send plot data to file." } ,
+    { "wrs2p", com_write_sparam, FALSE, TRUE,
+      { 1, 041000, 041000, 041000 }, E_DEFHMASK, 0, LOTS,
+      NULL,
+      "file : Send s-param data to file." } ,
     { "hardcopy", com_hardcopy, FALSE, TRUE,
       { 1, 041000, 041000, 041000 }, E_DEFHMASK, 0, LOTS,
       NULL,
@@ -605,6 +598,10 @@ struct comm nutcp_coms[] = {
       { 1, 041000, 041000, 041000 }, E_DEFHMASK, 2, LOTS,
       NULL,
       "file plotargs : Send plot data to file." } ,
+    { "wrs2p", com_write_sparam, FALSE, TRUE,
+      { 1, 041000, 041000, 041000 }, E_DEFHMASK, 0, LOTS,
+      NULL,
+      "file : Send s-param data to file." } ,
     { "hardcopy", com_hardcopy, FALSE, TRUE,
       { 1, 041000, 041000, 041000 }, E_DEFHMASK, 0, LOTS,
       NULL,

src/frontend/postcoms.c

@@ -524,6 +524,149 @@ com_write(wordlist *wl)
     return;
 }
 
+/* Write scattering parameters into a file with Touchstone File Format Version 1
+with command wrs2p file .
+Format info from http://www.eda.org/ibis/touchstone_ver2.0/touchstone_ver2_0.pdf
+See example 13 on page 15: Two port, ASCII, real-imaginary
+Check if S11, S21, S12, S22 and frequency vectors are available
+Check if vector Rbase is available
+Call spar_write()
+ */
+
+void
+com_write_sparam(wordlist *wl)
+{
+    char *file;
+    char* sbuf[6];
+    wordlist *wl_sparam;
+    struct pnode *n;
+    struct dvec *d, *vecs = NULL, *lv = NULL, *end, *vv, *Rbasevec=NULL;
+    struct pnode *names;
+    bool scalefound, appendwrite=FALSE;
+    struct plot *tpl, newplot;
+    double Rbaseval;
+
+    if (wl) {
+        file = wl->wl_word;
+    } else
+        file = "s_param.s2p";
+    /* generate wordlist with all vectors required*/
+    sbuf[0] = "frequency";
+    sbuf[1] = "S11";
+    sbuf[2] = "S21";
+    sbuf[3] = "S12";
+    sbuf[4] = "S22";
+    sbuf[5] = NULL;
+    wl_sparam = wl_build(sbuf);
+
+    names = ft_getpnames(wl_sparam, TRUE);
+    if (names == NULL)
+        return;
+    for (n = names; n; n = n->pn_next) {
+        d = ft_evaluate(n);
+        if (!d)
+            return;
+        if (vecs)
+            lv->v_link2 = d;
+        else
+            vecs = d;
+        for (lv = d; lv->v_link2; lv = lv->v_link2)
+            ;
+    }
+    Rbasevec = vec_get("Rbase");
+    if (Rbasevec)
+        Rbaseval = Rbasevec->v_realdata[0];
+    else {
+        fprintf(stderr, "Error: No Rbase vector given\n");
+        return;
+    }
+
+    /* Now we have to write them out plot by plot. */
+
+    while (vecs) {
+        tpl = vecs->v_plot;
+        tpl->pl_written = TRUE;
+        end = NULL;
+        bcopy(tpl, &newplot, sizeof (struct plot));
+        scalefound = FALSE;
+
+        /* Figure out how many vectors are in this plot. Also look
+         * for the scale, or a copy of it, which may have a different
+         * name.
+         */
+        for (d = vecs; d; d = d->v_link2) {
+            if (d->v_plot == tpl) {
+                vv = vec_copy(d);
+                /* Note that since we are building a new plot
+                 * we don't want to vec_new this one...
+                 */
+                vv->v_name = vec_basename(vv);
+
+                if (end)
+                    end->v_next = vv;
+                else
+                    end = newplot.pl_dvecs = vv;
+                end = vv;
+
+                if (vec_eq(d, tpl->pl_scale)) {
+                    newplot.pl_scale = vv;
+                    scalefound = TRUE;
+                }
+            }
+        }
+        end->v_next = NULL;
+
+        /* Maybe we shouldn't make sure that the default scale is
+         * present if nobody uses it.
+         */
+        if (!scalefound) {
+            newplot.pl_scale = vec_copy(tpl->pl_scale);
+            newplot.pl_scale->v_next = newplot.pl_dvecs;
+            newplot.pl_dvecs = newplot.pl_scale;
+        }
+
+        /* Now let's go through and make sure that everything that 
+         * has its own scale has it in the plot.
+         */
+        for (;;) {
+            scalefound = FALSE;
+            for (d = newplot.pl_dvecs; d; d = d->v_next) {
+                if (d->v_scale) {
+                    for (vv = newplot.pl_dvecs; vv; vv =
+                            vv->v_next)
+                        if (vec_eq(vv, d->v_scale))
+                            break;
+                    /* We have to grab it... */
+                    vv = vec_copy(d->v_scale);
+                    vv->v_next = newplot.pl_dvecs;
+                    newplot.pl_dvecs = vv;
+                    scalefound = TRUE;
+                }
+            }
+            if (!scalefound)
+                break;
+            /* Otherwise loop through again... */
+        }
+
+        spar_write(file, &newplot, Rbaseval);
+
+        /* Now throw out the vectors we have written already... */
+        for (d = vecs, lv = NULL;  d; d = d->v_link2)
+            if (d->v_plot == tpl) {
+                if (lv) {
+                    lv->v_link2 = d->v_link2;
+                    d = lv;
+                } else
+                    vecs = d->v_link2;
+            } else
+                lv = d;
+        /* If there are more plots we want them appended... */
+        appendwrite = TRUE;
+    }
+    return;
+}
+
+
 /* If the named vectors have more than 1 dimension, then consider
  * to be a collection of one or more matrices.  This command transposes
  * each named matrix.

src/frontend/postcoms.h

@@ -11,6 +11,7 @@ void com_unlet(wordlist *wl);
 void com_load(wordlist *wl);
 void com_print(wordlist *wl);
 void com_write(wordlist *wl);
+void com_write_sparam(wordlist *wl);
 void com_transpose(wordlist *wl);
 void com_setscale(wordlist *wl);
 void com_display(wordlist *wl);

src/frontend/rawfile.c

@@ -740,3 +740,105 @@ fixdims(struct dvec *v, char *s)
     }
     return;
 }
+
+/* Write a s-param file according to format Touchstone Vers. 1. */
+
+void
+spar_write(char *name, struct plot *pl, double Rbaseval)
+{
+    FILE *fp;
+    bool realflag = TRUE;
+    int length, numdims, dims[MAXDIMS];
+    int i, j, prec;
+    struct dvec *v, *lv;
+
+    /* Why bother printing out an empty plot? */
+    if (!pl->pl_dvecs) {
+	fprintf(cp_err, "Error writing s2p: plot is empty, nothing written.\n");
+	return;
+    }
+
+    if (raw_prec != -1)
+        prec = raw_prec;
+    else
+        prec = 6;
+
+    numdims = length = 0;
+    for (v = pl->pl_dvecs; v; v = v->v_next) {
+
+        /* All vectors have to have same length,
+        only dimension 1 is allowed */
+        if (length == 0) {length = v->v_length;}
+        if (length != v->v_length) {
+            fprintf(stderr,"Error writing s2p: lentgth of vector %s differs from length of vector 'frequency'\n",
+                v->v_name);
+            return;
+        }
+        if (v->v_numdims != 1) {
+            fprintf(stderr,"Error writing s2p: Dimension of vector %s greater than 1\n",v->v_name);
+            return;
+        }
+
+    /* Find the length and dimensions of the longest vector
+     * in the plot.
+     * Be paranoid and assume somewhere we may have
+     * forgotten to set the dimensions of 1-D vectors.
+             
+        if (v->v_numdims <= 1) {
+            v->v_numdims = 1;
+            v->v_dims[0] = v->v_length;
+        }
+        if (v->v_length > length) {
+            length = v->v_length;
+            numdims = v->v_numdims;
+            for (j = 0; j < numdims; j++) {
+                dims[j] = v->v_dims[j];
+            }
+        }*/
+    }
+
+    if (!(fp = fopen(name, "w"))) {
+        perror(name);
+        return;
+    }
+
+    fprintf(fp, "!2-port S-parameter file\n");
+    fprintf(fp, "!Title: %s\n", pl->pl_title);
+    fprintf(fp, "!Generated by ngspice at %s\n", pl->pl_date);
+    fprintf(fp, "# Hz S RI R %g\n", Rbaseval);
+    fprintf(fp, "!%-*.5s  %-*.5s  %-*.5s  %-*.5s  %-*.5s  %-*.5s  %-*.5s  %-*.5s  %-*.5s\n", 
+        prec+8,"freq",
+        prec+8,"ReS11",prec+8,"ImS11",prec+8,"ReS21",prec+8,"ImS21",
+        prec+8,"ReS12",prec+8,"ImS12",prec+8,"ReS22",prec+8,"ImS22");
+
+    /* Before we write the stuff out, make sure that the scale is the first
+     * in the list.
+     */
+    for (lv = NULL, v = pl->pl_dvecs; v != pl->pl_scale; v = v->v_next)
+        lv = v;
+    if (lv) {
+        lv->v_next = v->v_next;
+        v->v_next = pl->pl_dvecs;
+        pl->pl_dvecs = v;
+    }
+
+    /* print frequency first as real value, the real and imag part of 
+    S11, S21, S12, S22 respectively */
+    for (i = 0; i < length; i++) {
+	    for (v = pl->pl_dvecs; v; v = v->v_next) {
+            if (i < v->v_length) {
+                if (cieq(v->v_name, "frequency"))
+                     fprintf(fp, "% .*e  ", prec,
+                     realpart(&v->v_compdata[i]));
+                else
+                    fprintf(fp, "% .*e  % .*e  ", prec,
+                      realpart(&v->v_compdata[i]),
+                      prec,
+                      imagpart(&v->v_compdata[i]));
+            } 
+        }
+        (void) putc('\n', fp);
+    }
+    (void) fclose(fp);
+    return;
+}

src/frontend/rawfile.h

@@ -7,6 +7,7 @@
 #define RAWFILE_H_INCLUDED
 
 void raw_write(char *name, struct plot *pl, bool app, bool binary);
+void spar_write(char *name, struct plot *pl, double val);
 struct plot * raw_read(char *name);
 
 

src/include/fteext.h

@@ -324,6 +324,7 @@ extern void com_unlet(wordlist *wl);
 extern void com_load(wordlist *wl);
 extern void com_print(wordlist *wl);
 extern void com_write(wordlist *wl);
+extern void com_write_sparam(wordlist *wl);
 extern void com_destroy(wordlist *wl);
 extern void com_splot(wordlist *wl);
 extern void com_setscale(wordlist *wl);
@@ -332,6 +333,7 @@ extern void com_transpose(wordlist *wl);
 /* rawfile.c */
 extern int raw_prec;
 extern void raw_write(char *name, struct plot *pl, bool app, bool binary);
+extern void spar_write(char *name, struct plot *pl, double val);
 extern struct plot *raw_read(char *name);
 
 /* meas.c */