| 摘要 |
A digital Non Return to Zero (NRZ) and Frequency Modulated (FM) radio transmitter intended but not unique to, for the transmission of Digital, Tone Only or Tone and Voice paging messages is described. This transmitter is built on the concept that the separate signals required are individually constructed, and then combined together into the actual RF output. This provides for optimized circuitry for each particular function for the highest performance. There is no reason for compromising the performance of a particular function, and the implementation of the modulation and synthesis with direct digital technology provides extremely linear and fast radio performance at no extra cost. Maintenance is also simplified since the individual blocks can be troubleshooted and repaired (or replaced) requiring a minimum of down time.
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