N Series (GJB681A-2002 / MIL-C-39012)
GJB681A Series RF Coaxial Connector
The GJB681A family is Hengji's military-grade RF coaxial connector platform, designed, manufactured and qualified to GJB681A-2002 — the Chinese national military standard equivalent to MIL-C-39012. One 50 Ω interface platform spans the SMA, SMB, SSMB, MCX, MMCX, N and BNC series, covering threaded, snap-on and bayonet coupling in plug, square-flange receptacle, bulkhead and jam-nut body styles. Solder, crimp and PCB terminations accept flexible, semi-rigid and semi-flexible cable, with gold-plated brass or passivated stainless-steel shells and PTFE dielectric for stable VSWR and low insertion loss. Typical uses include avionics, radar, satellite and microwave equipment, test instrumentation, and wireless base-station RF interconnections.
Product Description & Technical Specifications
TECHNICAL DATASHEET1. Product Overview & Features
The GJB681A family is Hengji's military-grade RF coaxial connector platform, designed, manufactured and qualified to GJB681A-2002 — the Chinese national military standard equivalent to MIL-C-39012. One 50 Ω interface platform spans the SMA, SMB, SSMB, MCX, MMCX, N and BNC series, covering threaded, snap-on and bayonet coupling in plug, square-flange receptacle, bulkhead and jam-nut body styles. Solder, crimp and PCB terminations accept flexible, semi-rigid and semi-flexible cable, with gold-plated brass or passivated stainless-steel shells and PTFE dielectric for stable VSWR and low insertion loss. Typical uses include avionics, radar, satellite and microwave equipment, test instrumentation, and wireless base-station RF interconnections.
- Qualified to GJB681A-2002 (MIL-C-39012) — the national military standard for RF coaxial connectors.
- One 50 Ω platform covering SMA, SMB, SSMB, MCX, MMCX, N and BNC interfaces.
- Threaded (SMA, N), snap-on (SMB, SSMB, MCX, MMCX) and bayonet (BNC) coupling options.
- Plug, square-flange receptacle, bulkhead and jam-nut body styles.
- Solder, crimp and PCB terminations for flexible, semi-rigid and semi-flexible cable.
- Gold-plated brass or passivated stainless-steel shells with PTFE dielectric.
- Low contact resistance (≤ 3.0 mΩ inner / ≤ 2.0 mΩ outer) and 500-cycle mating life.
2. Technical Specifications
| Executive Standard | GJB681A-2002 (MIL-C-39012) |
|---|---|
| Characteristic Impedance | 50 Ω |
| Series Covered | SMA / SMB / SSMB / MCX / MMCX / N / BNC |
| Frequency Range | SMA DC–18 GHz (semi-rigid) / N DC–11 GHz / SMB & BNC DC–4 GHz / SSMB DC–3 GHz |
| Coupling Style | Threaded (SMA, N) / Snap-on (SMB, SSMB, MCX, MMCX) / Bayonet (BNC) |
| Body Styles | Straight plug / square-flange receptacle / bulkhead / jam-nut receptacle |
| Termination | Solder, crimp and PCB / flange mount |
| Center Contact | Beryllium copper or phosphor bronze, gold plated |
| Shell & Metal Parts | Brass, gold or nickel plated; stainless steel, passivated or gold plated |
| Insulator | PTFE (polytetrafluoroethylene) |
| Contact Resistance | Inner conductor ≤ 3.0 mΩ; outer conductor ≤ 2.0 mΩ |
| Insulation Resistance | ≥ 5000 MΩ (SMA / N / BNC); ≥ 1000 MΩ (SMB) |
| Dielectric Withstanding Voltage | 1500 V (N, BNC) / 1000 V (SMA) / 750 V (SMB) |
| VSWR | ≤ 1.15 + 0.02 f (SMA, flexible cable); ≤ 1.3 (N, BNC, SMB) |
| Durability | 500 mating cycles |