Cable-Mount Connector
Understanding Cable-Mount Connectors
You cannot use an RF connector without attaching it to something. While panel-mount connectors bolt to metal chassis, Cable-Mount Connectors are engineered specifically to grip onto the soft, flexible layers of a coaxial cable.
Attaching a connector to a cable is a highly precise, destructive mechanical process. If the technician strips the Teflon dielectric 1 millimeter too short, the impedance of the joint is ruined, causing a massive VSWR spike at the connector base.
The Anatomy of Attachment
Every cable-mount connector must make two completely separate, flawless electrical connections: one to the center wire, and one to the outer braided shield.
| Attachment Method | The Mechanical Process | Engineering Tradeoffs |
|---|---|---|
| Crimp / Crimp | The center pin is crimped onto the center wire using a specialized hex-die tool. The outer ferrule is crimped over the braided shield. | Pros: Extremely fast assembly for high-volume manufacturing. Very reliable under vibration. Cons: Cannot be disassembled or repaired. If crimped incorrectly, the center pin geometry is crushed, ruining high-frequency performance. |
| Solder / Crimp | The center pin is meticulously hand-soldered to the center wire. The outer shield is crimped. | Pros: Phenomenal electrical performance. Soldering the center pin ensures zero resistance and excellent PIM performance. Cons: Slower assembly. Requires highly skilled technicians to avoid melting the Teflon dielectric during soldering. |
| Clamp (Field Installable) | Uses a threaded back-nut and a rubber gasket to physically clamp down on the outer shield. | Pros: Can be installed in the field with basic wrenches. Reusable. Cons: Bulky, heavy, and highly susceptible to coming loose over time, causing massive PIM issues. Rarely used above 3 GHz. |
Hardline (Corrugated) Cable Mounting
Flexible braided cables (like RG-58) are easy to crimp. However, massive cell tower cables (like LDF4-50A) use solid, corrugated copper pipes for their outer shields. You cannot crimp a solid copper pipe. Connectors for corrugated cables use a complex Flaring process, where a specialized tool physically bends the edge of the copper pipe outward, and the connector tightly bolts down against the flared lip to create a flawless, PIM-free 360-degree contact.
Key Equations
A Cable-Mount Connector is an RF interface specifically designed to be permanently attached to the raw end of a bulk coaxial cable, terminating the transmission...
Key specifications:
1 m | 3 GHz | -50 A | 0 dB | 1 mW | 30 dB
Power: P(dBm) = 10log(PmW), 0dBm = 1mW
Comparison
| Connector | Freq Max | Impedance | Power | Interface |
|---|---|---|---|---|
| SMA | 18 GHz | 50 Ω | 0.5 W | Threaded |
| N-Type | 11 GHz | 50 Ω | 5 W | Threaded |
| 2.92mm (K) | 40 GHz | 50 Ω | 0.3 W | Threaded |
| 1.85mm (V) | 67 GHz | 50 Ω | 0.2 W | Threaded |
| 1.0mm (W) | 110 GHz | 50 Ω | 0.1 W | Threaded |
Frequently Asked Questions
Does the cable type matter when buying a connector?
Absolutely. You cannot buy a generic 'SMA Male' connector. You must buy an 'SMA Male for RG-316' or an 'SMA Male for LMR-400'. Every single coaxial cable has different jacket thicknesses and dielectric diameters. The internal ferrule of the connector must perfectly match the exact physical dimensions of the cable, or it will not fit.
What is the 'pull strength' of a crimped connector?
A properly crimped connector should have a pull strength exceeding the physical break-strength of the cable itself. If a technician yanks on a heavy cable, the braided copper wires should snap before the crimp ferrule ever lets go. If the connector slides off, it was severely under-crimped.
Why do some high-frequency cables use solder-solder connectors?
For elite semi-rigid cables (which use a solid copper outer jacket instead of a braid), crimping is impossible. The center wire is soldered to the pin, and the entire outer copper jacket of the cable is directly induction-soldered to the brass body of the connector. This creates an absolutely flawless, continuous metal shield capable of 50 GHz performance.