above. The Moon must be above the horizon in order for EME communications to be possible. Voyager program The Voyager program spacecraft have the highest known path loss (308dB as of 2002) and lowest link budgets of any telecommunications circuit. The Deep Space Network has been able to maintain the link at a higher than expected bitrate through a series of improvements, such as increasing the antenna size from 64m to 70m for a 1.2dB gain, and upgrading to low noise electronics for a 0.5dB gain in 2000–2001. During the Neptune flyby, in addition to the 70-m antenna, two 34-m antennas and twenty-seven 25-m antennas were used to increase the gain by 5.6dB, providing additional link margin to be used for a 4× increase in bitrate. See also Friis transmission equation Antenna gain-to-noise-temperature Isotropic radiator Radiation pattern Multipath propagation RF planning References External links Link budget calculator for wireless LAN Link budget tutorial Point-to-point link budget calculator MUOS Link budget calculator/planner Example LTE, GSM and UMTS Link Budgets Python link budget calculator for satellites Small satellites link budget (with python examples) Budgets Telecommunications engineering Radio frequency propagation