## Attachment 'fra0.c'

```   1 // fra0.c  fraunhofer rings and low elevation SSPS rectenna.
2 // cc -o fra0 fra0.c -lm
3 //
4 // This computes the path from an -5° SSPS to a rectenna at 46° N
5 // and 30° west.  This gives us the antenna elevation.  We then
6 // assume a circular aperture, and a rectenna expanded by 1/sin(elevation)
7 // to catch diagonal beams.
8 //
9 // Skolnik says 0.7dB loss at 2.5 GHz and 25 degrees elevation,
10 //   thus an 85% efficiency multiplier.  If the rectenna is 85%
11 //   efficient, and we have 91% beam capture efficiency and 95%
13 //   is 69% .  That turns 7 GW broadcast into 4.8 GW to the customer.
14
15 #define	 STEP	0.001		// m q step
16 #define  DMAX	2113.1000	// m   rectenna diameter
17 #define	 APER	5000.0000	// m   ssps aperture diameter
18
19 #define  FREQ	2.450E+09	// hz  frequency
20 #define	 C	2.998E+08	// m/s lightspeed
21 #define	 GEO	42164000	// m GEO radius
22 #define  RE	6371000  	// m Earth radius
23 #define  SOUTH	5.00    	// degrees SSPS offset latitude south
24 #define  LAT	46.1920  	// degrees rectenna latitude
25 #define	 LON	30.0000		// degrees rectenna longitude west
26
27 #include <math.h>
28 #include <stdio.h>
29
30 int main() {
31    double pi   = 4.0*atan(1.0)			 ;//       pi
32    double d2r  = atan(1.0)/45.0			 ;//       degrees to radians
33    double r2d  = 45.0/atan(1.0)			 ;//       radians to degrees
34    double dNS  = SOUTH+LAT			 ;// deg   northsouth
35    double rNS  = d2r*dNS	         	 ;// rad   northsouth
36    double wl   = (C/FREQ)			 ;// m     wavelength
37    double rEW  = d2r*LON			 ;// rad   eastwest
38    double rtot = acos(cos(rNS)*cos(rEW))	 ;// rad   total angle
39    double dtot = r2d*rtot			 ;// deg   total angle
40    double zz   = RE*sin(rtot)			 ;// m     Z
41    double xg   = GEO-RE*cos(rtot)		 ;// m     X to geo
42    double dist = sqrt( zz*zz + xg*xg )		 ;// m     distance
43    double rel  = atan(xg/zz)-rtot		 ;// rad   elevation
44    double del  = r2d*rel			 ;// deg   elevation
45    double d    = APER				 ;// m     aperture diameter
46    double xsca = pi * d / (wl*dist)		 ;// 1/m   scaling argument
47
48    double qs   = STEP				 ;// m     integration step
49    double q    					 ;// m     center of annulus
50
51    double i0p  = 2.0*qs/xsca*xsca		 ;// 1/m2  power scaling
52    double pow  = 0.0				 ;//       total power
53    double bs                                     ;//       bessel function
54    double btest                                  ;//
55    double rmax = 0.5*DMAX			 ;// m     rectenna diameter
56
57    for( q = 0.5*qs ; q < DMAX ; q += STEP ) {
58       bs   = j1(xsca*q)       			 ;// m2	   additional area
59       pow += bs * bs / q			 ;//
60    }
61    pow *= i0p 					 ;//
62    double lost = 1.0 - pow                       ;//
63    double sin1 = 1/sin(rel)                      ;//
64    double sin2 = DMAX/sin(rel)                   ;//
65
66    printf( "%10.3e    bessel\n"                  , bs    ) ;
67    printf( "%10.7f    fractional power\n"        , pow   ) ;
68    printf( "%10.7f    lost power\n"              , lost  ) ;
69    printf( "%9.1f m   Rectenna diameter\n"       , DMAX  ) ;
70    printf( "%9.1f m   SSPS diameter\n"           , APER  ) ;
71    printf( "%9.4f°    SSPS south\n"              , SOUTH ) ;
72    printf( "%9.4f°    Rectenna latitude\n"       , LAT   ) ;
73    printf( "%9.4f°    Rectenna longitude\n"      , LON   ) ;
74    printf( "%9.4f°    Rectenna total angle\n"    , dtot  ) ;
75    printf( "%9.4f°    Rectenna elevation\n"      , del   ) ;
76    printf( "%9.5f     Rectenna 1/sin\n"          , sin1  ) ;
77    printf( "%9.1f     Rectenna D/sin\n"          , sin2  ) ;
78    printf( "%10.3e m  distance\n"                , dist  ) ;
79    return(0);
80 }
```

## Attached Files

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• [get | view] (2015-06-02 03:02:57, 3.5 KB) [[attachment:fra0.c]]
• [get | view] (2015-06-04 06:45:55, 2614.3 KB) [[attachment:ghtc2015.pdf]]
• [get | view] (2015-06-04 06:46:07, 50.7 KB) [[attachment:ghtc2015.tex]]
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