In many portable instruments, the noise and EMI of its switch power supply must be solved, the preferable method is that EMI power is reduced with spread spectrum frequency technique.

在许多便携式设备中，其开关电源的噪声和电磁干扰(emi)是亟待解决的问题，比较好的办法是利用扩频技术来减少EMI信号的功率成分。

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They were expecting to see one certain frequency or one line in the spectrum at this point here.

他们预计会看到某个特定的频率，或者在这里的光谱中的一条线。

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They suggest that any alien civilisation worth its salt would alight not on the photons of the electromagnetic spectrum-whether optical or radio-frequency-to send messages to other solar systems.

他们指出，任何有头脑的外星文明都不会发射电磁波谱中的光子——无论是可见光波段还是射频波段——向另一个太阳系传送信息。

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But there is a limited amount of radio frequency spectrum available.

VOA: special.2010.03.19

So, let's say they were expecting to see one certain frequency or one line in the spectrum at this point here.

比如说他们预计会看到某个特定的频率,或者在这里看到一个谱线。

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The mobile firm has made no secret of its desire to get its hands on lower-frequency spectrum, which can cover much larger areas and offers better indoor coverage than the high-frequency spectrum it currently owns.

BBC: Mobile firm on rural net crusade

"Low-frequency spectrum on a network as big as ours is a real notspot-killer, " he said.

BBC: Mobile firm on rural net crusade

Developed for secure government communications, Spitfire uses a broad frequency spectrum virtually immune to eavesdropping or interference.

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