#include <stdio.h>
#include "math.h"
main()
{
	double series();
	double square();
	int i;
	double F0, F1, F2, F3, F4, F5, F6, F7;
	double C0, C1, C2, Pad_C, Cvar_Min, Cvar_Max, C6, C7;
	double K0, K1, K2,  K3, K4, K5, Osc_total_C, Little_Guess, Big_Guess;
	double pi, T1, T2, X1, X2, track_error=1000, T0;
	double L0, Aer_L, Osc_L;
	
	printf("\nMin input frequency in MHz       ");
	scanf("%lf",&F3);
	F3 = F3 * 1e6;
	
	printf("\nMax input frequency in MHz       ");
	scanf("%lf",&F4);
	F4 = F4 * 1e6;
	
	printf("\nIntermediate frequency in MHz    ");
	scanf("%lf",&F7);
	F7 = F7 * 1e6;
	
	printf("\nMax tuning capacitor value in pF ");
	scanf("%lf",&Cvar_Max);
	Cvar_Max = Cvar_Max * 1e-12;
	
	printf("\nMin tuning capacitor value in pF ");
	scanf("%lf",&Cvar_Min);
	Cvar_Min = Cvar_Min * 1e-12;
/*	
	printf("\n\n*****\n%f\n%f\n%f\n%f\n%f\n*****\n",
	        F3, F4, F7, Cvar_Max*1e12, Cvar_Min*1e12);
*/	
	pi = 3.1415926805;
	F1 = ( F3 + F4 ) / 2.0;
	F5 = F3 + F7;
	F6 = F4 + F7;
	T1 = 0;
	T2 = 0;
	
	/* Aerial Circuit */
	X1 = square( F4 / F3);
	C1 = (Cvar_Max - X1*Cvar_Min)/(X1-1);
	Aer_L = square( 0.5/( pi * F3 )) /( C1 + Cvar_Max );
	
	/* Oscillator Circuit */
	X2 = square( F6 / F5);
	Big_Guess = Cvar_Max * 1e4;
	Little_Guess = Cvar_Min / 1e4;
	
	
	/* Make a guess at Padding Capacitor value */
	
	for(;track_error > 100;) {
		Pad_C = sqrt( Little_Guess * Big_Guess);
/*		
		printf("\nTrying Padder value %12.2lf pF.", Pad_C * 1e12);
	
		printf("\n*****\n%lf   %lf   %lf   %lf\n*****\n",
	        Pad_C, Little_Guess, Big_Guess, track_error);
*/	
		C6 = series( Cvar_Max, Pad_C );
		C7 = series( Cvar_Min, Pad_C );
		
		C2 = (C6 - X2 * C7) / (X2 -1);
		Osc_L = square( 0.5 / ( pi * F5) ) / (C6 + C2);
		
		/* Now see if our guess was any good */
		C0 = square( 0.5 / ( pi * F1 ) ) / Aer_L - C1;
		Osc_total_C = C2 + series( C0, Pad_C);
		F2 = 0.5 / (pi * sqrt( Osc_L * Osc_total_C ));
		track_error = ( F2 - (F1 + F7));
		
		if( track_error >  50)
			Big_Guess = Pad_C;
			
		if( track_error < -50)
			Little_Guess = Pad_C;
			
		track_error = fabs( track_error);
	}
	
/*
	printf("\n\n*****\n%lf   %lf   %lf   %lf\n*****\n",
	        Pad_C, Little_Guess, Big_Guess, track_error);
*/
	        
/* List Tracking Error versus Frequency */

	printf("\n\nAerial Freq.     Osc. Freq.     Track Err.");
	printf("\n       Hz.             Hz.            Hz.\n");
	
	F1 = F3;
	for(i=1; i<=11; i++) {
		C0 = square(0.5/( pi * F1)) / Aer_L - C1;
		K2 = series( C0, Pad_C ) + C2;
		F2 = 0.5/( pi * sqrt( Osc_L * K2) );
		T0 = F2 - F1 - F7;

		/* Update Worst error figures */

		if( T0 < T1 )
			T1 = T0;
		if( T0 > T2 )
			T2 = T0;

		printf("\n%12.2lf   %12.2lf   %12.2lf", F1, F2, T0);
		F1 += ( F4 - F3 )/10.0;
	}

	printf("\n\nWorst tracking error %12.2lf to %12.2lf\n\n",T1, T2 );
	printf("\nAerial circuit values       Oscillator values\n");
	printf("\nInductor %12.2lf uH    Inductor %12.2lf uH",Aer_L * 1e6, Osc_L * 1e6);
	printf("\nTrimmer  %12.2lf pF    Trimmer  %12.2lf pF",C1 * 1e12, C2 * 1e12);
	printf("\n                            Padder   %12.2lf pF\n",Pad_C * 1e12);
	
}

double square(A)
double A;
{
	return( A * A );
}

double series(A,B)
double A,B;
{
	return( A * B / ( A + B));
}