I designed a simple low frequency doubler, but I'm having trouble fixing the offset of my output signal. Below is my LTSpice model:

[![enter image description here](https://i.stack.imgur.com/0VF9Z.png)](https://i.stack.imgur.com/0VF9Z.png)

On the graph you see my green input signal, blue inverted signal, and then red re-combined signal with double frequency. My main issue is that my output is offset by 35mV. I've tried a few things but none of them seem to work. Does anyone know a simple way to bring the offset back to zero?

Frequency range: 50Hz - 1500Hz. Low voltage input. Op amp is receiving +-5V.