This thesis investigates new techniques exciting microwave whispering gallery modes in Perovskite crystals, and reveals the underlying physics of phonons and spins. Such a system probes two-level and multi-level states for fundamental physics development and quantum applications. Masured hyperfine-structure including Jahn-Teller effects proofs high preecision of the performed ultra-sensitive spectroscopy. Nuclear perturbation and identified ferromagnetic state of Mn4+ ion shows nephelauxetic-effect. Performed investigations using the achieved experimental results leads to a new level of advanced physics study.