LimeSDR - Measurements

Introduction

tbd

Equipment

• LimeSDR mini  bought at Mouser.com 
• Preamplifier 
• WIFI Poweramplifier EDUP 

Preamplifier

The preamplifier is rated with a gain of 18dB with -0.9dB/GHz if I interpret the datasheet correctly, the amplifier should have a gain of about Diese E-Mail-Adresse ist vor Spambots geschützt! Zur Anzeige muss JavaScript eingeschaltet sein!.

The maximum input power at 2GHz is rated with 22dBm.

So you should power the amplifier with +7dBm to get 22dBm output power.

Measured is a gain of 9dB. So only 1/4 of the rated output power is generated.

Poweramplifier

The poweraplifier has a specified maximum output power of 39dBm which equals to 8W.

The maximum input power is rated as 20dBm (100mW). This would end up in an gain of 19dB. But on the package there is a typical gain of 17dB specified - hm?!

The measurements show a gain of 11db - this 6db away from the typical gain - or only 1/4 of the output power is reached.

Measurements

Reference trace

Preamplifier

Preamplifier + Poweramplifier

Conclusion as of 2019-04-13

If the devcies specifications are correct, the stacked amplifiers should give a gain of about 17dB + 15dB = 32dB. 

• With input power of 0dBm, the output power should be 32dBm ~ 1.6W.
• With input power of 5dBm, the output power should be 37dBm ~ 5.0W 

As can be seen, the output power produced by the stacked amplifiers is only +20dBm = 100mW.