//產生一個chirp信號



#include <math.h>
double y[10000];

void chirp(double f0,int n,int N,double Tr,double k,double T,double a,double fs)/*f0載頻，k調頻斜率，Tr取樣周期，T脈寬，a方波幅度，n一周期內取樣點數，N脈沖個數*/
	{		
	    	int i,m;
			double x,pi;
			pi=3.14159;
			double rect; 
		 
		 	for(i=0;i<n;i++)
		 		 {
		 		     x=i/fs;
		 		     if(x<=T&&x>=0)
					 rect=a;
					 else rect=0;
 		         	 y[i]=rect*cos(2*pi*f0*x+pi*k*x*x);
		          }
		          	 if(N!=1)
		          		{
				     		for(m=1;m<N;m++)
				     		{
			             	for(i=0;i<n;i++)
				             y[n*m+i]=y[i];
				             }
		          		}


	}

main()
	{
	    int n,N;
		double Tr,f0,k,T,a,B,fs;
		B=7e+7;//帶寬
		fs=1e+8;
		Tr=4e-5;
		n=2300;
		f0=9.6e+10;
		T=2e-5;
		k=B/T;
		a=1;
		N=3;
		chirp(f0,n,N,Tr,k,T,a,fs);
	}