Transatlantic 2.5 MChip/s two-way satellite time and frequency transfer with surface acoustic wave filters

From August 2010 to April 2011, NIST and OP conducted an experiment of using surface acoustic wave (SAW) filters in transatlantic two-way satellite time and frequency transfer (TWSTFT) with 2.5 MChip/s pseudo-random noise (PRN) codes. The SAW filters used in the experiment are 2.5 MHz band-pass filters with a center frequency of 70 MHz. Instead of using 3.5 MHz bandwidth required for the 2.5 MChip/s signal, the use of SAW filters allows the 2.5 MChip/s TWSTFT to use only 2.5 MHz bandwidth on a satellite transponder. We evaluated the SAW filters. We compared the time transfer instability of the filtered 2.5 MChip/s TWSTFT to the 1 MChip/s TWSTFT with and without the SAW filters. This paper presents the experiment results.