N to SMA cables and adapters for antennas

SMA to N cables and adapters create competent physical and electrical connections between two of the leading classes of radio frequency connectors and is often used for connecting antennas and base station components.

Both connectors are hard-wearing, threaded, suitable for outdoor installation, and found on a range of radio components. The N connector, in particular, is rugged and suitable for long-term outdoor installation. Between-series SMA/N connector adapters are precision machined for excellent signal conduction, without discontinuities that impair performance. SMA to N cables use flexible, low-loss cables to add utility to this already practical combination of connectors.

About the SMA connector

This threaded subminiature connector is mated by screw coupling and is rated for over 500 mating cycles.

Physical specifications of the SMA connector

• Dimensions: the male connector's diameter is 7⁄16 inches (11 mm) and the female connector's diameter is 3⁄8 in (9.5 mm)
• Threading: 36 threads per inch
• Material: gold or nickel-plated machined brass with a Teflon insulator
• Male SMA connector: cylindrical body with outer hex-nut and internalized threads. Center pin conductor.
• Female SMA connector: barrel-shaped body with externalized threads, inner beryllium copper receptacle, and silicone rubber gasket.

Electrical specifications of the SMA connector.

• Nominal impedance: 50 ohms
• Frequency range: 0 to 18 GHz
• Voltage rating: 500 volts.
• VSWR: 1.05 to 1.15
• Contact resistance: 2.0 milliohms.
• Insertion resistance: 5000 megaohms.
• Signal leakage: -90dB max (at 2 to 3 GHz)

About the N connector

The N connector is a medium-sized threaded connector that is rated for over 500 mating cycles.

Physical specifications of the N connector

• Threaded medium-size connector
• 5/8 - 24 pitched UNEF threading
• Material: nickel-plated brass or stainless steel
• Male N connector: diameter of 0.800 inches (20.3 millimeters) with internalized threads and hex nut
• Female N connector: diameter of 0.620 inches (15.7 millimeters)with externalized threads
• O-ring seal achieves an IP 67 rating, making the connection dust and moisture-free
• Standard N connectors do not have a dielectric

Electrical specifications of the N connector

• Nominal impedance: 50 ohms
• Maximum frequency: up to 11 GHz
• Peak voltage rating: 1500 volts
• Dielectric withstanding voltage: up to 2500 volts.
• VSWR of 1.3.
• Contact resistance: 1 milliohm
• Insertion loss: 0.15 dB.
• Signal leakage: -90 decibels at 3GHz.

SMA to N cables    

These cable assemblies use a semi-rigid, double-shielded cable that is known for its low attenuation and reliable performance. The SMA to N cables are available in two diameters:

1. 100-series coax: this flexible double-shielded coax has an overall diamete of 2.79mm
2. 200-series coax: this larger diameter coax also has low attenuation and isa better choice for outdoor installations.

SMA to N cables and adapter applications

Outdoor antennas

N connectors can support the long-term mounting and performance of outdoor antennas. The nickel plating and silicone rubber gaskets make the N connector durable. Combining an N connector with an SMA connector enables you to run an antenna cable from the SMA connector of an indoor radio device to the N connector of an outdoor antenna.

Surge protection

N connectors are routinely used in lightning arrestors and surge protection devices (SPDs). You can use SMA to N cables to install arrestors in line ahead of sensitive electronic equipment that you want to protect from a lightning strike or surge.

Cellular base stations

Both N and SMA connectors are used in cellular networking because they have good power handling and frequency limit that accommodates cellular frequencies. These cables can be used to connect components that include antenna arrays, transceivers, and digital signal processors.

Testing and measurement

SMA to N connector cables and adapters are used in instrumentation setups that include power amplifiers, network analyzers, and automated test equipment.