Last week，we finish 20 ?pcs EP2 sample for RF module,
?Fistly尊浪，we need to test PCBA ?performance test .include tranamitted power, frequency deviation匣屡，and harmonic wave，that took a long time拇涤，but not to worry捣作，we can finish it。
Secondly 工育，we must complete three product test in this week虾宇，because customer need to check it and prepare the next ?mass production搓彻，Based oncustomerneeds,inmeeting theperformanceandreliability?underthepremise?ofcustomerstoselectthe mostpricecompetitiveproductsisourdefinitionofquality.
? Lastly如绸，the distance test must be completed today嘱朽，and analysis the data，come up with a credible solution to slove the problem about ?signal attenuation怔接。（Um搪泳，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扼脐，carrier signal岸军，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.?
