EEVblog Electronics Community Forum
Electronics => RF, Microwave, Ham Radio => Topic started by: miduchp on December 24, 2017, 09:14:25 am
-
Hello everyone,
I'm quite a newbie regarding RF designs. I've recently started to experiment with RFM69HW-433 modules to put them together with my Atmega based sensors. In order to have compact design, I've started to experimeth with Linx Technologies sourface mount antennas https://www.linxtechnologies.com/wp/wp-content/uploads/ant-433-sp.pdf (https://www.linxtechnologies.com/wp/wp-content/uploads/ant-433-sp.pdf)
I've prepared following adapter (https://thumb.ibb.co/mN51em/IMAG0421.jpg) (https://ibb.co/mN51em), in order to experiment with radios using prototype boards.
The problem is my radios are getting killed. After a short time, there radios staring to have short circuit. It was not happening whem I was using antenna of 1/4 wavelength done from piece of wire.
Should I have some matching circuit for antenna ? Is there any way to tune it without spectrum analyzer ?
Could you be so kind to give me any clue / materials to read so I could fix this issue ?
Regards,
Piotr
-
The ANT433 is DC coupled to ground. Make sure your module has a DC blocking capacitor. Also, you might want to add a matching network, as the antenna might not be exactly 50 Ohm on your board.