RF/microwave systems with large number of elements usually require switching elements with very small footprint, but providing very good electrical performance, low switching times, and good power-handling capabilities. In this sense, nonvolatile switches based on 2-D materials are emerging as a very suitable alternative to CMOS or MEMS-based technologies, mainly due to the capability of keeping a certain state with no energy consumption. In this article, different switches have been designed and fabricated using a multilayered structure based on 18 2-D hexagonal boron nitride (hBN) layers on three different substrates, high-resistivity silicon, quartz, and polycrystaline CVD diamond. The proposed device has been characterized in a frequency range up to 26.5GHz for these three substrates. The ON-state resistance and off-state capacitance have been extracted from experimental data using an equivalent electric model being 28~\Omega and 22 fF, leading to insertion losses (ILs) better than 2.5 dB in case of CVD diamond, and isolation better than 10 dB in case of quartz, for the on- and off-states, respectively.