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Design >> RF Design >> Loop Antenna
https://designers-guide.org/forum/YaBB.pl?num=1141999512

Message started by ic_engr on Mar 10^th, 2006, 6:05am

Title: Loop Antenna
Post by ic_engr on Mar 10^th, 2006, 6:05am

Hello,

I have a body worn Rx using an Antenna (llop antenna) tuned to received in the 900MHz range. The model is RLC, where in one end is connected to the LNA input and the other end is connected to the system ground. The reception seems to be low and crappy when I move beyond a certain distance. However, I did some experimentation wherein I placed a metal plate 2mm above the loop antenna on the top side with the metal plate connected to ground. This seems to improve my distance. What I dont understand is why the reception is improveing.

Please note on one side of the antenna is the PCB with circuitry. The PCB is about 4mm below the loop antenna. The metal plate with ground is placed on the other side of the loop antenna about 2mm spacing.

Does it make a difference if the loop antenna is made to stay opn in air instead of connecting to ground.

Please give as many suggestions as possible.

Tx

ic_engr.