## 4 Summary and Conclusions  
This work provides different MWs configurations to obtain a tunable and multiple response in the L and S bands (GHz). In addition, the suitability of different external stimuli, such as the application of AC and DC magnetic fields and the overlapping of variable thickness of polymer slabs, are demonstrated for the modulation of the microwave scattering coefficient. A ferromagnetic amorphous Co-based MW with low magnetostriction is the sensing material used, which presents high intensity electromagnetic scatterings that can be modulated by GMI effects. When MW linear arrays are fabricated, the amplitude of the microwave scattering is intensified and the resonant frequency \(f_{\rm min}\) shifts towards lower frequencies as the MW length increases. Subsequently, three array configurations are designed and a substantial improvement in attenuation amplitude is achieved in configurations 2 and 3 with \(\sim\)\(-\)16.8 and \(\sim\)\(-\)47.9 dB, respectively. In addition, a large reduction of the FWHM of the band pass filter of \(\sim\)0.03 GHz is obtained for configuration 3, narrowing the bandgap that is associated with the antenna resonance. When external DC and AC magnetic fields up to 17 Oe are axially applied through the MWs, the antenna resonance signature is progressively flattened and broadened. These effects are caused by the change in surface impedance produced when the MW switches from a circumferential anisotropy (maximum attenuation state) to an axial anisotropy (minimum attenuation state). With the DC field applied, variations of \(\sim\)62%, \(\sim\)67% and \(\sim\)77% are obtained for configurations 1, 2, and 3, respectively. In contrast, an adjustable response in the time domain representation is also obtained when an AC magnetic field is applied. Furthermore, the addition of different thicknesses of overlapping polymeric slabs can be discerned with high sensitivity (5.10\({}^{-3}\) dB/\(\upmu\)m), due to the high resolution of the measurements. Interestingly, measurements as a function of overlapping polymeric thicknesses evidence the ability of these sensing array platforms to experimentally obtain different matching thicknesses at a fixed frequency within the dipole resonance range. These features open up the possibility of applying these configurations as overlapping thickness measurement platforms. An advanced approach is also successfully tested by intercalating Cu MWs in the Co-based array to improve the intensity of microwave scattering, while maintaining the ability to tune its properties by the stimuli that are described above. As an application example, configuration 2 improves from \(\sim\)\(-\)14.4 dB to \(\sim\)\(-\)17.8 dB with Co-based MWs and with a Cu MWs intercalation in the Co-based one, respectively. In addition, a maximum difference of approximately 40% of the absorbed signal is obtained with an applied DC magnetic field with intensity of 17 Oe by maintaining an electromagnetic shielding of \(\sim\)\(-\)11.2 dB at \(\sim\)2.38 GHz. Conceptualization, P.M. and E.N. ; methodology, P.M., E.N., D.A. and J.L.-S.; validation, P.M., E.N., D.A., J.L.-S. and A.H.; formal analysis, P.M., E.N., D.A., J.L.-S. and A.H.; investigation, P.M., E.N., D.A., J.L.-S. and A.H.; data curation, P.M., E.N., D.A. and J.L.-S.; writing--original draft preparation, P.M., E.N., D.A. and J.L.-S.; writing--review and editing, P.M., E.N., D.A., J.L.-S. and A.H.; supervision, P.M., E.N., D.A., J.L.-S. and A.H.; funding acquisition, P.M. All authors have read and agreed to the published version of the manuscript. Funding: The authors acknowledge the Spanish Ministry of Industry, Economy and Competitiveness for financing the project MAT2015-65445-C2-1-R, MAT2017-86450-C4-1-R, MAT2015-67557-C2-1-P, RTI2018-095856-B-C21, and RTI2018-095303-A-C52, the Comunidad de Madrid by S2013/MIT-2850 NANOFRONTMAG and S2018/NMT-4321 NANOMAGCOST, and the European Commission under H2020 frame by AMPHIBIAN Project ID: 720853.