50 Ohm Fakra Plug, 9 GHz — Code D Keying
The Amphenol RF FM4-NDRP-PCB-1 is a 50 Ohm Fakra plug from the AUTOMATE series, designed for single-port coaxial RF interconnect in automotive-grade applications. It carries a male pin contact and uses a Code D keying feature — that color-coded violet/claret housing and latch lock prevent cross-mating with other Fakra codes in a multi-connector harness. The right-angle through-hole mounting puts the plug parallel to the board, saving height in a tight enclosure.
What the 50 Ohm and 9 GHz Ratings Mean for the RF Path
The 50 Ohm impedance is standard for RF signal chains — antenna feeds, telematics modules, and GNSS receivers all expect a 50 Ohm transmission line. The 9 GHz max frequency covers the full 5 GHz Wi-Fi band and most automotive radar bands, with headroom for emerging V2X channels. The LCP dielectric and brass/zinc alloy body with tin finish keep the return loss in check across that band; the shield termination is soldered to the PCB ground plane, so the launch impedance stays clean if the footprint matches the recommended land pattern.
Code D Keying — Why It Matters in a Multi-Connector Harness
Fakra connectors come in color-coded keying variants — Code A, B, C, D, Z, etc. — each with a unique housing shape and latch position. The FM4-NDRP-PCB-1 uses Code D, which means it physically cannot mate with a Code A or Code B receptacle. In a vehicle or equipment harness carrying multiple RF signals (e.g., GPS, cellular, satellite radio), the keying eliminates mis-mating at the assembly line or during field service.