We propose a reconfigurable 8PSK/8QAM modulator implementation by employing two cascaded QPSK modulators with an interferometer in between. With simple control of bias voltage of the interferometer, a flexible switching between 8PSK/8QAM can be achie
基于直接数字频率合成DDFS（Direct Digital Frequency Synthesize）技术，依据调制信号相关原理，设计以DDS集成电路AD9851为核心的正弦信号发生器，可精确输出幅度调节范围为50mV PP ~20V PP ，频率调节范围100Hz~30MHz的正弦波，还可输出调幅波、调频波、PSK、ASK信号。该设计在宽频带内能获得大幅度的低失真波形。采用多种抗干扰措施以减少噪声并抑制高频自激，通过软件补偿提高频带内输出幅度的平坦度。该系统输出波形谐波
The relation between the phase shift and the mean optical power (MOP) output from a delay-line interferometer (DLI) port applied for phase-shift keying (PSK) signal demodulation is proven of a cosine law irrelevant to signal modulation condition. The
