The physics and the engineering formulas of 1/f noise in ErAs-based all-epitaxial, GaN-based, and other
types of Schottky diodes are presented in a way related to the general pn junction quantum 1/f noise
formulas developed by the author and van der Ziel earlier, but with inclusion of the image force
contribution of an electron at the metal-semiconductor interface. On this base the phase noise introduced
by mixers constructed with the ErAs Schottky diodes was also studied and can now be calculated
analytically with the Quantum 1/f effect formulas.