| 摘要 |
PURPOSE: To provide a phase sampling function by including a step to provide intermediate frequency signals by mixing L2 signals with signals of a local transmitter. CONSTITUTION: A computer 12 has timing and controlling functions as to synchronize the operation of an L2 card 14 and the operation of an L1 receiver 10. The card 14 receives L2 P-encoded signals through an antenna, a band-pass filter, and a low noise preamplifier for setting a system noise follower after the signals are properly converted for free space transmission through an r.f. cable 16. The outputs of an image rejection filter 20 are converted into nominal intermediate frequency(IF) values of 37.2 MHz by being added to a mixer 22 which receives signals of 1190.4MHz of a local transmitter. The IF signals are consequently added to a STOP terminal of a ÷32 counter 30 and, therefore, a phase sampling function can be obtained.
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