Cavity pulling in Galileo passive hydrogen maser

The paper derives the theoretical expression of the cavity pulling factor in Galileo space passive hydrogen Maser, based on the 'single frequency modulation'. The sensitivity of the cavity pulling vs. the phase selection is deduced in order to account for the experimental errors in the phase adjustments. The theoretical calculation shows the new phase setting exists to achieve a zero cavity pulling, and the preliminary experimental results comparing with the two phase selection are presented.