APARM2504-SG3 is a compact multi-constellation GNSS patch antenna designed to receive signals from GPS, GLONASS, Galileo, BeiDou, QZSS, IRNSS/NAVIC, and SBAS systems across multiple frequency bands. The antenna features a peak gain of 4.1 dBi at L1/E1 frequency (1575.42 MHz), with maximum efficiency of 89.2% at the G1 band (1602 MHz), and employs right-hand circular polarization (RHCP) for optimal signal reception. With dimensions of 25.0 × 25.0 × 4.0 mm and a weight of 10.4 g, it offers a compact form factor suitable for space-constrained applications, featuring through-hole and adhesive mounting options on ceramic substrate. The antenna operates reliably across -40°C to +105°C and maintains VSWR below 2.0, making it ideal for UAVs, drones, asset tracking, telematics, precision agriculture, and intelligent transportation systems requiring multi-constellation positioning accuracy.