# A complex integral

1. Jun 6, 2010

### singhofmpl

I'm studying the non-linearity effect of power amplifier on multicarrier signal. While modeling the behavior of power amplifier I came across the following integral; I'm not able to figure out how to solve it.

$$I=\frac{A^2}{2\sigma_x^4}\int_{0}^{\infty}\frac{r^3}{r^2+A^2}\exp(\frac{j\pi}{3}\frac{r^2}{r^2+A^2}-\frac{r^2}{2\sigma_x^2})dr$$

2. Jun 6, 2010

### Gib Z

I showed in the other thread how this integral can be simplified, but I've concluded that there isn't a closed form expression for that integral.

3. Jun 6, 2010

### singhofmpl

Thanks for your prompt response. I think I'm left with no option but to apply numerical methods. I have one more problem if you can give me some direction to solve it. The integral is given below:
$$\int_{0}^{\infty}(a*\Lambda^2/(\Gamma*(\gamma-\Lambda)^2))*exp(\Lambda*\gamma/(\Gamma*(\gamma-\Lambda))-(\gamma-b)/c)d\gamma$$