Reconfigurable microwave devices which operate without any external bias magnetic field are of great importance for monolithic device integration of microwave components. Magnetic nanostructures and arrays are found to be promising due to the ease of their control parameters. However, use of a bias magnetic field for tunable microwave operation hinders the advantage of nanomagnets. Here, we propose a novel method for reconfigurable microwave operation based on zigzag nanowires which do not require any external bias magnetic field. Tunable microwave operation relies on reconfigurable remanent magnetic states which are associated with distinct magnetization dynamic responses. Owing to two different domain configurations for different remanent magnetic states, variation of internal magnetic fields governs the observed tunability of microwave operating frequency. In addition, microwave properties are highly sensitive to the zigzag angle which offers additional functionality along with bias-field-free operation. © 2020 IOP Publishing Ltd.