Microwave watt meter

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cmac76
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Posts: 15
Joined: Tue May 24, 2011 11:12 am

Microwave watt meter

Post by cmac76 »

I am looking for a watt meter for 6 and 11 ghz microwave. Hoping for something small and that could be adapted to a wide range of freqs. Any advise would be great!
Al
Posts: 1045
Joined: Tue Sep 04, 2001 4:00 pm

Re: Microwave watt meter

Post by Al »

You didn't say what power range(s) you're wanting to measure or what kind of accuracy you're looking for in your measurements. Because of the short wavelengths at 6 and 11 Ghz, inline type power meters are not common(I've never seen one). The more common methods consist of a thermoelectric power head/meter and a directional coupler at 6 & 11 Ghz or a thermoelectric power head/meter and calibrated(at 6 & 11 Ghz) attenuator. If the power levels are relatively low(less than +30 dBm or so) only a thermoelectric power head/meter would be needed. Thermoelectric power measuring elements are inherently broadband in nature(50 Mhz to 18 Ghz is common).
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Bill_G
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Joined: Thu Sep 17, 2009 5:00 am

Re: Microwave watt meter

Post by Bill_G »

I've used both Anritsu and Agilent power meters. They are an external sensor and extension cable that plugs into their multi-purpose RF analysis device with the power meter option loaded. Most modern microwave products have an internal power measurement screen you access with your laptop. I use the external power meter during system construction as part of the ATP to verify OEM calibration. After that, I rely on the internal meter comparing it to my RSL records for verification.

As Al explained, they are low power devices with a max input of +30dbm which is adequate for modern systems. Sometimes there is a decoupled measurement port already available with the attenuation factor printed on it that you plug into your power meter offset. But, if the customer requires you measure power at the top of the stack, put a load on, with an attenuator, so you don't burn up the sensor. Never plug the sensor straight into the xmit line without some kind of pad.

I rent power meters when they are required for a job so I can avoid the cost of purchase, have a valid cal sticker, and not tie up our test equipment for weeks as I work hither, thither, and yon. That let's me record the return loss of the waveguide before I attach to it as well.

Agilent Guide to Power Meters and Sensors
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fineshot1
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Joined: Wed Oct 12, 2005 5:13 am

Re: Microwave watt meter

Post by fineshot1 »

We use a slightly older HP5348A, if you can pick up one of them for a good deal, they work well
up to about 26Ghz with the Sensor we have.

http://www.keysight.com/upload/cmc_uplo ... =US&lc=eng
fineshot1
NJ USA
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