基于零中频的新型调制体制遥测发射机设计

Design of a New Modulation System Telemetry Transmitter Based on Zero Intermediate Frequency

随着我国航天器新型号的发展,无线遥测数据量急剧增长,受频谱所限,脉冲编码调制/调频(PCM/FM)体制已无法满足未来航天运载器高码率遥测系统的带宽需求。同时考虑到超外差发射机方案结构复杂、功耗大和成本高等缺点,急需一款可以适应高码率且结构简单的产品。设计一种零中频体制新型调制方式的发射机,采用多调制指数连续相位调制(Multi-h CPM)方式,相较于PCM/FM调制方式,输出信号具有频谱主瓣窄、旁瓣低、包络恒定、频带利用率高的特点,同时正交变频方式也极大地简化了设计,可较好地适应未来航天遥测系统需求。所提出的基于零中频的新型调制体制遥测发射机性能优良、带内外无杂波干扰,满足发射机各项指标要求。

With the development of new launch vehicle products in China,the telemetry data volume of aerospace has rapidly increased.Due to the limitation of spectrum performance,the pulse code modulation/frequency modulation（PCM/FM） system has been unable to meet the bandwidth requirements of high-data-rate telemetry systems of future spacecraft. At the same time considering such shortcomings of superheterodyne transmitter scheme as complex structure,high power consumption and high cost,a product that can adapt to high data rate and simple structure is urgently needed.In view of this development direction and demand,this paper designs a new zero-IF modulation system transmitter by using the multi-h continuous phase modulation（Multi-h CPM）.Compared with the PCM/FM,the output signal has such advantages as narrow spectrum main lobe,low side lobe,constant envelope,high bandwidth utilization,while the orthogonal frequency conversion method is also greatly simplified and able to satisfy the requirements of future aerospace telemetry system. The new modulation system telemetry transmitter based on zero-IF proposed in this paper has such advantages as excellent performance,no in-band and outband clutter interferences,and meeting the requirements of various specifications of transmitter.