超短波跳频电台频率合成器设计  

Design of Frequency Synthesizer for VHF Band Frequency Hopping Radio

作　　者：徐建斌[1] 尹锁柱[1] 

机构地区：[1]桂林电子科技大学,广西桂林541004

出　　处：《广西通信技术》2007年第4期21-25,共5页Guangxi Communication Technology

摘　　要：针对超短波电台对频率合成器所提出的指标要求,设计了合成器的实现方案,并依据方案软硬结合实现了一套频率合成器。方案中采用了基于∑-△调制的小数分频技术,既实现了很小的频率分辨率又消除了因小数分频而引起的杂散。实验结果表明,其杂散小于-70 dBc,锁定时间小于150 us,频率间隔为25 kHz,这些性能可以满足超短波跳频电台的指标要求。This paper lays out a practical synthesizer scheme based on the required target for VHF hand radio, and realizes a set of synthesizer which combines software and hardware. The scheme adopts sigma - delta fractional - N PLL, which can achieve smaller frequency interval and eliminate the spurs caused by fractional- N PLL. Experimental results indicate that spurs is less than -70dBc, settling time is less than 150us and frequency interval is 25KHz, which can meet VHF band frequency hopping radio＇s need.

关 键 词：超短波 整数分频锁相环 小数分频锁相环 ∑-△调制 频率合成器 

分 类 号：TN74[电子电信—电路与系统]