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本发明是有关使用模拟调频器的相位连续数字调频器(频率键控)。相位连续数字调频与数字调相(相位键控)比较,当采用同步检波或延迟检波的相位面检波时,在误码特性方面,与数字调相一样,但由于调制频谱展宽小,包络线恒定。因此有不受功率放大器非线性影响的优点。要进行相位面检波时,若中心频率为f_c,则码的钟频与调制波的频差〔f_d(Hz)〕和调制波按照码(的状态)形成f_1=f_c-f_(d/2)(Hz)或f_2=f_c+f_(d/2)(Hz)才符合所定义的调制指数〔m=(f_1-f_2)/f_b=f_d/f_b〕。这样,就可以利用整数倍钟频频率的脉冲发生器和分频器构成数字式的调制器。
The present invention relates to a phase continuous digital frequency modulator (frequency keying) using an analog tuner. Phase-continuous digital frequency modulation and digital phase modulation (phase keying) comparison, when using synchronous detection or delay detection of the phase surface detection, the error characteristics, as with the digital phase modulation, but the modulation spectrum broadening is small, the envelope Constant. Therefore, the power amplifier is not affected by the nonlinear advantages. To perform phase plane detection, if the center frequency is f_c, the frequency difference between the clock frequency and the modulation wave of the code [f_d (Hz)] and the modulation wave form f_1 = f_c-f_ (d / 2) (Hz) or f_2 = f_c + f_ (d / 2) (Hz) satisfy the defined modulation index [m = (f_1-f_2) / f_b = f_d / f_b]. In this way, it is possible to make use of an integer multiple of the clock frequency pulse generator and frequency divider to form a digital modulator.