The inspection of metallic structures using guided ultrasonic waves is an essential task in nondestructive testing, particularly due to its ability to detect damage over long distances. Among the various types of guided waves, shear horizontal (SH) waves stand out for their low dispersion, simple modal structure, and high robustness in industrial applications. The generation of these waves using electromagnetic acoustic transducers (EMATs) is especially advantageous, as it enables fully non-contact operation, high tolerance to coated surfaces, and considerable flexibility in selecting wave polarization and propagation direction. However, conventional periodic permanent magnet (PPM) EMATs are limited by their structural nature: their nominal wavelength is determined solely by the magnetic periodicity of the magnet array. As a result, each device operates efficiently at only one wavenumber, restricting the transducer to a single mode or region of the dispersion curve - an important drawback in inspections that require multiple frequencies, different SH modes, or varying penetration depths. This work addresses this limitation by studying a new concept of a dual-wavelength PPM EMAT, based on the spatial superposition of two elementary PPM arrays with distinct periodicities. By combining two wavelengths in a single device, it becomes possible to access two independent wavenumbers, enhancing modal selectivity and enabling greater adaptability to different operational regimes. The simultaneous presence of two periodicities results in a composite spatial spectrum, in which two fundamental components coexist, each associated with one of the constituent arrays. Thus, the main objective of this study is to analyze, model, and validate the spatial behavior of the Lorentz force in this hybrid EMAT, demonstrating how the incorporation of two distinct magnetic periodicities enables the selective excitation of SH waves at two different wavelengths using a single transducer, overcoming the intrinsic limitations of conventional PPM EMATs. To achieve this, three complementary levels of analysis are employed: a simplified theoretical model, magnetostatic finite-element simulations, and frequency-domain finite-element simulations (FEM-FS), enabling an integrated evaluation of the device. The results show that the predicted periodicities are reproduced with errors below 5 percent, and that the hybrid transducer exhibits two well-defined excitation bands, confirming its ability to operate selectively at both nominal wavelengths.