【摘要】 分析了锁相环技术与直接数字频率合成技术的工作原理,提出了结合两种技术设计高频电磁法仪器信号源的方法。克服了以往单纯采用锁相环技术设计信号源时跳频时间长、频率准确度低的弱点,测试结果显示,该方法设计的信号源频率准确度高,到小数点后两位,输出交、直流电压衰减小,达到信号源设计要求。更多还原

【Abstract】 The principle of phase\|locked loop and direct digital synthesizer are discussed. The method of designing signal source of high frequency electromagnetic instrument is proposed by combining two techniques which gets rid of the weak point of phase\|locked loop. The frequency accuracy is improved to two bit after point and the output AC(Alternating Current) and DC(Dirfect Current) voltages decrease less. The satisfied test results demonstrate DDS(Direct Digital,Synthesizer) have a bright application future in geo\|exploration instrumentation.更多还原