Reprogrammable microwave properties based on magnetic nanostructures are of great interest for future information-processing technologies in the GHz frequency range. Tunable microwave properties are typically obtained by varying the bias magnetic field, which, however, hinders the device integration capability at the nanoscale. Here, we show a route for bias-field-free giant tunability of microwave properties based on isolated and dipolar coupled networks of multilayer rhomboid nanomagnets. A comprehensive investigation of multilayers beyond trilayer and various complex networks of them are carried out using micromagnetic simulations. The giant tunability of the microwave properties has been attributed to the strong dipolar field variations associated with different remanent states which can be reconfigured with a nanosecond pulse field. We have also presented an approach for realization of an artificial 3D antiferromagnetic crystal. These results have potential applications in fast reprogrammable and energy-efficient microwave devices which operate without any bias magnetic field. © 2018 IOP Publishing Ltd.