This paper by Handel, presented at the International Symposium on Single Photon based Quantum Technologies in Berlin, examines quantum theory of 1/f frequency fluctuations Part 1, focusing on de-coherence as the cause of fundamental 1/f noise. The research establishes that quantum decoherence processes resulting from environmental interactions and measurement-induced wavefunction collapse are the primary physical mechanism generating fundamental 1/f noise in oscillators, sensors, and quantum systems, providing rigorous theoretical foundation connecting decoherence theory with ubiquitous 1/f noise observations.