Coaxial connectors primarily feature characteristic impedances of 50Ω and 75Ω; 50Ω models are used for RF communications and test instrumentation, while 75Ω models are mainly used for video signals and cable TV systems. BNC connectors support a frequency range of 0 to 4 GHz; SMA connectors range from DC to 18 GHz (with some types reaching 26.5 GHz); and N-type connectors range from 0 to 11 GHz (with enhanced versions reaching 18 GHz). Voltage Standing Wave Ratio (VSWR) is a key indicator of signal matching; for BNC connectors, a good VSWR value is typically ≤1.3; for straight SMA connectors, it is usually ≤1.10 + 0.02f; and for N-type connectors, the VSWR falls between 1.08 and 1.15 in the 0.8 GHz to 2.4 GHz range.
Regarding insertion loss, SMA connectors typically exhibit ≤0.15 dB at 6 GHz, while N-type connectors generally show ≤0.12√GHz. In terms of rated voltage, BNC connectors have an operating voltage (insulation) of 750 V, SMA connectors operate at 335 Vrms, and N-type connectors can handle up to 1000 Vrms. Regarding contact and insulation resistance, BNC connectors have a maximum center contact resistance of 1.5 mΩ and an outer conductor resistance of 0.5 mΩ; SMA connectors have a center contact resistance of ≤3 mΩ and an outer conductor resistance of ≤2.5 mΩ; N-type connectors have an inner conductor contact resistance of ≤1.0 mΩ and an outer conductor contact resistance of ≤0.25 mΩ; and the insulation resistance for common connectors is typically ≥5000 MΩ.
Regarding mechanical durability, the mechanical lifespan (mating cycles) of coaxial connectors should generally exceed 500 cycles.
Environmental parameters include operating temperature range and ingress protection ratings; common coaxial connectors typically operate within the range of -65°C to +155°C. Some models (such as N-type) offer water and dust resistance meeting the IP67 standard. When selecting a connector, factors such as impedance matching, frequency range, voltage standing wave ratio (VSWR), power rating, and mounting method (e.g., panel mount, cable mount, or PCB mount) must be considered. Generally, straight connectors offer superior electrical performance compared to right-angle connectors, while threaded connectors provide better electromagnetic compatibility than bayonet or push-pull types. Unless system requirements dictate otherwise, connectors offering higher performance or incurring higher costs are typically not selected.