We are planning to use CC2538 in our next generation product – a RPM recorder – to add wireless connectivity, as removing the device to retrieve data requires much labor.
The circuit must be fitted within a 1-inch diameter hole, which is drilled on a steel rod, as shown in the picture I attached. And sealed with epoxy from the top.
Only a very short wireless range is required (typically within 1 feet), it’s like an RFID, and we can design device with much larger antenna and power budgets to which it communicates.
My thought is to use a dipole PCB antenna where no balun is required. And whether folded or half wave length… I don’t know. I have limited knowledge of antenna design. So any recommendation?
http://www.ti.com/lit/an/swra421/swra421.pdf
I think it will be similar with this one, the half wavelength dipole antenna, where I only have to decrease the radius of the antenna’s arc to around 12mm.
