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公开(公告)号：US3752923A
公开(公告)日：1973-08-14
申请号：US3752923D
申请日：1971-12-09
发明人： BURKE N
CPC分类号： H04L27/12
摘要： A transmitter produces a plurality of frequencies for application to a communications channel by generating a number of triangular waveforms in response to a plurality of selection signals and converts these waveforms into their respective frequencies.
摘要翻译： 发射机通过响应于多个选择信号产生多个三角形波形而产生用于应用于通信信道的多个频率，并将这些波形转换成它们各自的频率。
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公开(公告)号：US3752922A
公开(公告)日：1973-08-14
申请号：US3752922D
申请日：1971-12-09
发明人： BURKE N
CPC分类号： H04L27/10
摘要： An FSK transmitter includes a crystal controlled generator which includes a counter which when cycled provides a number of output signals which are logically combined to produce pulse waveforms having different repetition frequencies. The generator counter is arranged to be cycled in accordance with the state of bilevel signals applied to a plurality of input selection lines to apply pulse waveforms of the appropriate repetition frequencies to an output circuit for transmission over a communications channel. The transmitter further includes a ramp generator which is synchronized with cycling of the crystal controlled generator and which is also operative in response to the state of input selection lines to produce pulse waveforms whose repetition frequencies approximate those produced by the crystal controlled generator. During a shift in frequency, the transmitter uses the ramp generator waveforms to establish the cycle time of the counter so as to provide a nominal time period for the pulse waveforms being applied to the output circuit during the time of frequency shift thereby minimizing distortion of the waveforms at the time of crossover.
摘要翻译： FSK发射机包括晶体控制发生器，其包括计数器，当循环时，计数器提供多个逻辑组合的输出信号，以产生具有不同重复频率的脉冲波形。 发生器计数器被布置成根据施加到多个输入选择线的双电平信号的状态循环，以将适当重复频率的脉冲波形施加到输出电路，以在通信信道上传输。 变送器还包括与晶体控制的发生器的循环同步的斜坡发生器，并且响应于输入选择线的状态产生脉冲波形，其脉冲波形的重复频率接近由晶体控制的发生器产生的脉冲波形。 在频率偏移期间，发射机使用斜坡发生器波形来建立计数器的周期时间，以便在频率偏移期间为施加到输出电路的脉冲波形提供标称时间间隔，从而最小化 交叉时的波形。
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