2018.2.27 RF module distance test part I

Last week，we finish 20  pcs EP2 sample for RF module,

 Fistly，we need to test PCBA  performance test .include tranamitted power, frequency deviation，and harmonic wave，that took a long time，but not to worry，we can finish it。

Secondly ，we must complete three product test in this week，because customer need to check it and prepare the next  mass production，Based oncustomerneeds,inmeeting theperformanceandreliability underthepremise ofcustomerstoselectthe mostpricecompetitiveproductsisourdefinitionofquality.

  Lastly，the distance test must be completed today，and analysis the data，come up with a credible solution to slove the problem about  signal attenuation。（Um，that‘s a bit difficult ）

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The record of distance test today as follow。

1  The principle of RF

Firstly, basedona lot of literature anoverview ofRFtechnology is presentedincluding fundamental wave signal，carrier signal，modulation and demodulation signals.

Theprocess ofretrievingintelligence(data)from amodulatedcarrierwave;thereverse ofmodulation.

Whenreceiving,the modemperformsthe reverseprocess, anddemodulatesthedatafrom thecarriersignal. 

 2 Environment disturbance

Thecommunicationsprotocolsusedbymobilephonesoftenresult inlow-frequencypulsingof thecarriersignal. 

 3  Characteristic

Theratioofpeak andaveragepower inmulticarriersystemis muchlarger than thatin single carrier system,and may grow unboundedlyas thenumberof subcarriersgrows toinfinity.