This is a Diabolo-shaped transmitter antenna with 500 µH inductance, designed for automotive applications like passive keyless entry systems (KES). Operating at frequencies of 20 kHz, 125 kHz, and 134.2 kHz, this antenna offers excellent stability across temperatures ranging from -40°C to +85°C. It also provides resonant frequency adjustments within ±2 kHz and meets the AEC-Q200 automotive quality standards. The compact design (67 x 45.66 x 16.5 mm) ensures mechanical robustness, making it ideal for automotive use