1. Range Issue :
Generally speaking, we have achieved the phase 1 goal except the transmission range is not long enough. The reason might be:
Tx antenna is not fully matched. The additional 28nH self-made inductor is not accurate enough might introduce parasitic capacitance and resistance.
We set the analog squelch in Rx higher to prevent Noise, however, it also "filtered" out weak signal. The Rx sensitivity drops.
Despite the issue, the Tx / Rx pair we built is able to transmit 2400 bps data up to 55 M or more. This could be used as a prototype in GPS location reporter.
The experience we have learned here could be a great help in building most of Tx / Rx module, which is the most important of all.
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2. Improvement Suggestion:
Order a real 27nH ( 21 - 34 nH) inductor to replace self-made inductor.
Try digital squelch to solve noise problem.
Test different Data rate with different bandwidth (Sel 0 , Sel1 inRx)
Tx Power does matter. Change another Tx chip with bigger transmission power. (Micrel has Tx chip with 10dBm max power)
An additional continuous testing data generator should be include in the test program to monitor real time channel quality.
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Special Thanks to :
Prof. Peter Kinget, our advisor, who gives us great help and valuable advise in the project.
Tasuya Hanasaka, our classmate and friend, who helps us perform the final demo.