Square PCB Coil for a PI detector

[lucifer]

Hi,
Making well balanced IB coils at home was always too difficult for me to do at home. That's why I decided to design an inductively balanced PCB coil for a PI detector. On the top layer there are two separate TX coils (9.5" x 4") wound in opposite direction connected in series and on the bottom layer there's a 4" RX coil. Entire design is completely symmetrical so induction balance is achieved by geometry of the coil.
The parameters of the PCB coil are:
- Overall dimensions: 10" x 10";
- TX inductance: ~ 300 uH;
- TX resistance: 19 Ohm
- RX inductance: ~ 1 mH
- RX resistance: 95 Ohm;
Some benefits of a PCB coil are less interwinding capacitance and the extremely low weight of the coil.
I'm going to drive the TX with a square current wave circuit.
Any ideas of more improvements/optimizations are welcomed.

[alex---1967]

Hello! Interesting. But, poor image quality. How many turns are there in the coils? Why is the coil resistance so high?

[lucifer]

Hello! Interesting. But, poor image quality. How many turns are there in the coils? Why is the coil resistance so high?

TX Coil is 2 x 23 turns each.
RX Coil has 103 turns.

Resistance depends on the trace width (0.635 mm for TX and 0.127 mm for RX). Resistance can be lowered (wider traces) but up to a certain point as the space on board is limited. With the circuit I have I expect +/- 150 mA square current wave through this coil. I'm currently working on a classic PCB DD coil but it's more complicated. Will post of I have any success with it and I can also share the Gerber files if anyone is interested.

[alex---1967]

and I can also share the Gerber files if anyone is interested.

Yes, it would be interesting to take a look... I was thinking of making a similar coil myself...

[lucifer]

Yes, it would be interesting to take a look... I was thinking of making a similar coil myself...

I've attached the Gerber files. I was able to create a DD coil too but it's less flexible and I'm unsure how well balanced it will be.

[Carl-NC]

You can increase the copper thickness, 2 ounce copper will cut the R in half.

[lucifer]

You can increase the copper thickness, 2 ounce copper will cut the R in half.

True, unfortunately it doubles the cost of manufacturing too.