Help Me Solve the Troubles about PCB Antenna

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varmear

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Apr 25, 2017
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beijing
Hello,all
I myself made a field intensity indicator recently,but I can’t always solve the part of antenna. I have copied other’s antenna as the following picture shows:

The antennas were made according to the frequency--2.5G. I have calculated the length of antennas: 1/4 wave length of 2.5G. I want to make a field intensity indicator with space triaxial. There is an equilateral triangle column consisted of three boards like this on. My questions:
1).What are the functions of two resistances--316ohm? I have tried to change it,but there are no any effects.
2). The antennas is copied by others,however the chip I used is LMV221 that is different from others.This is the datasheet of LMV221: http://www.kynix.com/uploadfiles/pdf9675/LMV221SDX.pdf you can learn details from it if needed. But the discreteness of boards is so big and the measuring signal form -20dbm to -5dbm showed here.
3).Do the antennas need impedance matching? Because in the inputted pins of LMV221,there are a down-pull resistance of 50oh.
4). The frequency response of this board is so bad. Can you solve this problem?
I’m the first time to learn antenna ! Please help me!
Thanks a lot.
Wishes
 

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