@ky2006170This took a lot longer than I thought it would take: designed a custom antenna for the #frc x #onboard trinket. It's specifically tuned for biz card.
Some additional resources for y'all curious in designing your own:
• NFC Antenna Design Webinar
• Key equation: Ideal Inductance = 1/( (2pi freq)^2 chip_capacitance))
• Impedance Calculator
• Antenna footprint generator