An angle grinder is provided including a radial fan assembly. Accordingly, moisture congregates only at a portion where the cross-section of the air passage is great, so that the external air smoothly passes into or out the heat exchanger through the air passage where the moisture congregation does not occur, minimizing the pressure drop, and efficiency in heat exchange of the heat exchanger can be thusly improved. The floating antenna element is configured to operate in conjunction with the first antenna element within a second operating frequency band. The single-chip multi-sublayer PHY comprises at least one selection register communicating with at least the program module, where the selection register is adapted to store at least the default polarity setting. The invention is characterised in that the capacitor of the filtering and interference suppression device is non-inductive.