This project provides a 3D-printable mechanical chassis designed for a 4-channel Angle of Arrival (AoA) direction-finding / RWR system covering a full 180° frontal azimuth sector. The holder is specially tailored to fit ultra-wideband (UWB) Vivaldi PCB antennas (48.2 mm x 38.0 mm) fabricated on 0.508 mm (20 mil) Rogers RO4350B substrate. ## Key Features-**180° Frontal Coverage:** 4 antenna channels oriented in a fan array at -67.5°, -22.5°, +22.5°, and +67.5° for optimal 45° beam crossover. -**RF Isolation Septa:** Features 2.5 mm thick vertical separation walls between adjacent channels to minimize mutual coupling and sharpen individual beam patterns. -**Tight Tolerance Slots:** 0.85 mm guide slots ensure a snug, precise fit for 0.508 mm thick PCBs without blocking the radiating aperture. -**SMA Clearance Windows:** Dedicated rear cutouts for Edge-Launch SMA connectors and phase-matched coaxial cabling. -**Mounting Point:** Central bottom mounting hole for standard tripods or laboratory fixtures. ## Assembly & Tip Slide the 4 Vivaldi PCB antennas into their respective slots. For maximum inter-channel isolation (>20 dB), line the vertical separation walls with conductive copper tape.