gōng chéng shī / yòng / bèi pín qì / bǎ / shū rù / xìn hào / de / pín lǜ / tí gāo / dào / yuán lái / de / liǎng bèi工程师用倍频器把输入信号的频率提高到原来的两倍。The engineer used a frequency multiplier to raise the input signal's frequency to twice its original value.