How to express this inverse complex series i know about geometric series in the normal form, but i've been incapable of find an expression for this series, any suggestions $$\sum_{n=-\infty}^{0}(2e^{-jw})^{n}$$ Thanks

$$\sum_{n=-\infty}^{0}(2e^{-jw})^{n} = \sum_{k=0}^{\infty}(2e^{-jw})^{-k} = \sum_{k=0}^{\infty} 2^{-k}e^{jwk} = \sum_{k=0}^{\infty} \left(\frac{e^{jw}}{2} \right)^{\\!k} $$