I am designing a bluetooth low energy device. It basically reads a sensor over I2C and collect data. You can check data in your phone whenever you want. I have two questions, one related with antennas and another one related with battery.
first of all, this is my layout so far
It is based in this schematic
IC2 is B1 from schematic, IC3 is X1. The left part is my specific sensor.
My questions are: First, the one related with antennas. Since this is a homemade project I do not have a vector network analyzer so I can't tune the antenna. However, I found this antenna from Texas Instruments:
They claim its impedance is 50 ohm, so could I just attach its 50 ohm feed point to my 50 ohm output from the balun? with a extremly short wire so I don't add extra resistance or inductance (or as low as possible)
Second question is I need it to be battery powered and small. I went for a CR2032 battery. However I checked its current specifications and it says 4mA maximum discharge current. I need around 20mA in some moments when the radio is working. I thought I could add a large capacitor (C14) so it can provide higher current for a short time and then it will be charged again when the system is sleeping. It is possible?
I added a pi-network just in case. My layout is this now
and this is the schematic
I'll use a 0 ohm resistor as R3. R4 and R5 are not mounted initially. This would allow to eventually tune the antenna, but it won't be easy since I don't have lab equipment. I am wondering if this would work without tuning?