We present the design and characterization of an integrated optical frequency shifter based on an IQ modulator featuring standard building blocks from a generic photonic integration Indium Phosphide (InP) foundry. The device is conceived to be used in applications with low bandwidth requirements such as dual-comb spectroscopy or integrated low-cost LiDARs. An initial analytical study of the system was carried out and subsequently validated by simulations. Then, we obtained experimentally the most relevant parameters of the system and evaluated its performance under frequency shifter operation. Good performance up to 250 MHz is achieved, thus proving its suitability for the intended applications.