能量测量，典型的NEJ约为1??

宽带光谱：30GHz到3THz以上

感应区域大约??0mm

探头

探头为声光探测器，使用密封的空气室和压力传感器。

使用电池内置金属薄膜的电阻加热方式校准。

支持单元

支持单元基于National Instruments USB-6211数据采集模块。

附带的电子器件可增加校准时的薄膜加热功能和放大从探头的扩音压力传感器输出的信号。

写入LabVIEW的软件应用了锁定放大器，可以显示微波功率。

Absolute Terahertz Power/Energy Meter

A new USB version of our successful absolute power meter support unit is now available,

with continuous FFT display of noise and dynamic as well as digital readout of power levels.

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The system is comprised of two parts:

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1. The power meter head. n
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2. The support unit, based on a National Instruments USB-6211 data acquisition module.
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Specifications:

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• Measures power in free-space beams n
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• Displays power on a computer n
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• Fully automatic absolute calibration using electrical film heating under software control n
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• Frequency dependent window loss correction n
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• Accuracy better than 10% n
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• NEP typically 5??/Hz^{??/sup> n}
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• For energy measurement the typical NEJ is about 1?? n
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• Broad Band: 30GHz to 3THz and beyond n
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• Sensitive Area greater than 30mm in diameter
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The Head

The head is a photo-acoustic detector using a closed air-cell and a pressure transducer.

Calibration is provided by ohmic heating of a thin metal film within the cell.

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The Support Unit

The support unit is based around a National Instruments USB-6211 data acquisition module.

Additional electronics have been added to provide film heating for calibration and to amplify

the signal from the head's microphone pressure sensor. The compiled software, written in

LabVIEW, implements a lock-in amplifier and displays the microwave power.

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