Recently, there has been significant interest on the fundamental science and technological applications of complex oxides and multiferroics. Low-power multiferroic have potential to fabricate and characterize frequency tunable, compatible with MMIC Technology, small light-weight for hand-held operation, cost-effective, high-frequency (>10GHz), devices for next generation communication devices and military applications. Multiferroic materials consists of both magnetic and ferroelectric phase and they offer the possibility of magneto-electric (ME) coupling. The purpose of this research is to show strong magnetic field dependent frequency tuning of multiferroics (Nickel doped BFO – BiFe1-xNixO3) based devices over a broad frequency band. We have shown here the magnetic field control of ferromagnetic resonance (FMR) field/frequency from C to Ku band frequencies. Nanoparticles of BiFe1xNixO3 (x=0.025 & 0.05) were prepared by auto combustion method. The XRD study confirms the formation of pure phase Bismuth Ferrite Nanoparticles. Ferromagnetism of un-doped BFO was enhanced by Ni substitution. Microwave characterization was done in co-planar waveguide (CPW) geometry both in field sweep and frequency sweep mode. BiFe1-xNixO3 nanoparticles were deposited using electrophoretic deposition method (EPD) on top of CPW to do the FMR experiments. The operating frequency of the device was tuned by application of magnetic field (H) over a wide range (5 to 20 GHz) with a field up to 8 kOe. Copyright © 2016 VBRI Press