Standing wave ratio calculation method

Standing wave ratio calculation formula

$$RL(db)=10{\log }_{10}^{\frac{P_{forward}}{P_{reflect}}}$$
$$VSWR=\frac{\frac{10^{RL(db)}}{20}+1}{\frac{10^{RL(db)}}{20}-1}$$

RF standing wave ratio calculation （ Online arrangement ）

$$VSWR=\frac{P_{forward}+P_{reflect}}{P_{forward}-P_{reflect}}$$

dbm db w mw Switch relationships

$$1dbm=10\ast {\log }_{10}^{\frac{Power}{1mw}}$$
$$30dbm=1W$$
$$1w=1000mw$$
$$db=a(dbm)-b(dbm)$$
$$db=10\ast lo{g}_{10}^{\frac{a(power)}{b(power)}}$$

C Code Record

#include <stdio.h>
#include <math.h>

double dbm2power(double dbm){
    
    return pow(10.0,dbm/10.0)/1000.0;
}

double vswr_accurate(double forward,double reflecte){
    
    return (pow(10.0,(10.0*log10(dbm2power(forward)/dbm2power(reflecte))/20.0))+1.0)/(pow(10.0,10.0*log10(dbm2power(forward)/dbm2power(reflecte))/20.0)-1.0);
}

double vswr_accurate_v2(double forward,double reflecte){
    
	return (pow(10.0,(forward-reflecte)/20.0)+1.0)/(pow(10.0,(forward-reflecte)/20.0)-1.0);
}

double vswr_rough(double forward,double reflecte){
    
    return ((dbm2power(reflecte)+dbm2power(forward))/dbm2power(forward)-dbm2power(reflecte));
}

int main(void){
    
    printf("pwr %lf \n",vswr_rough(26.0,20.0));
}