N Adapters (Type N)
Adapters with N connectors
Nickel-Plated for Weatherproofing and Outdoor Durability
Radio frequency adapters with an N connector are passive coaxial cable components that are capable of facilitating a mechanical and electrical connection between an N connector and another, distinct, type of radio frequency connector. They can be solid units that form a connection between each type of connector on either size or be a pigtail adapter with the two classes of connector separated by a short length of coax. A good quality N connector adapter should maintain the electrical connection and have fully matched impedance with discontinuities and signal loss kept to an absolute minimum. Adapters will also vary in gender and geometry to be able to make the required connection. N connector adapters also can be broadly divided into:
- In-series N connector adapters: in series adapters have the same type of connector on both sides. They may be male to male, male to female, female to female, and can be straight or right-angled.
- Between-series N connector adapters: between series adapter have an N adapter on one side and a different type of adapter (eg. SMA, RP-TNC, BNC) on the other side.
What is an N connector?
The N connector is a medium-sized, threaded radio frequency connector that is designed to conduct microwave frequencies. N connectors are used to connect antennas, coaxial cable, and other radio frequency equipment. It is also known as the N-type connector or Navy connector and is thought to be named after its designer, Paul Neill of Bell Labs, NY. Neill, an American electrical engineer, who designed the connector in the 1940s. It was a novel type of radio frequency connector as is was capable of handling microwave frequencies while being weatherproof and durable. The original design has, over time, been refined with precision improvements to enhance its performance with the multi-gigahertz frequencies in contemporary use.
N connector specs
N connector is manufactured in line with the military standard MIL-C-39012. It is available with either precision, industrial, or commercial-grade fabrication which will affect the cost and the frequency range of the connector. They may be standard N connectors or a helical variant, designed to accommodate corrugated coax.
Physical characteristics of the N-connector
The N connector is a cylindrical connector with an outer diameter of 0.827 inches (20.3 millimeters) for the male and 0.627 inches (15.7 millimeters) for the female. has 5/8-24 United Extra Fine (UNEF) pitch threading. The male and female connectors mate by screw coupling by hand for a weatherproof connection assisted by silicone or synthetic rubber gaskets. N connectors are robust and are rated for 500 mating cycles. Some versions are rated for 5000 mating cycles.
- The male N-type connector (plug) is made from brass, which may be silver or nickel-plated. It carries internal threads and has an inner mating interface with a silver or gold-plated brass pin conductor. The inner conductor is surrounded by air. Some male connectors also carry a hex nut to assist in tightening.
- The female N connector (jack) is made from brass and has externalized threads and an inner receptacle into which the male pin is inserted. It has no dielectric but carries a gasket to aid a moisture and airtight seal. The receptacle is made from phosphorus bronze or beryllium copper.
Electrical profile of the N-type connector
- Impedance: The N-type connector is available with either a 50 Ohm or 75 Ohm impedance. 50 Ohm N connectors are not fully compatible with 75 Ohm connectors and can cause damage to the connectors if mated. The 50 Ohm connector is widely used in mainstream applications such as wireless networking or amateur radio.
- Frequency range: The typical frequency range of the N connector is DC to 11 GHz. Precision N-type connectors can achieve a frequency range of up to 18 GHz depending on the manufacturer.
- Voltage rating: Voltage rating is important as the center conductor of the mated connector is surrounded by air. The peak voltage rating is 1500 volts.
- VSWR: Voltage Standing Wave Ratio is 1.35
- Insulation resistance: 5000 megohms
- Radio frequency leakage: -90dB at 3 GHz
- Insertion loss: .15 dB maximum at 10 GHz
Why are N-type connector adapters important?
The N connector is widely used because of its size, ruggedness, and consistent performance at high frequencies. These connectors are often selected for larger diameter, low loss coax, and high voltage rating for higher gigahertz frequencies also sets it apart for applications where robust power handling and increased data transfer are needed. N connectors are capable of being used to terminate a range of medium caliber and mini coaxial cables. It is easy to handle and forms a physically and electrically reliable connection that is available in a range of configurations including:
- Straight and right-angle plugs
- Bulkhead, panel mount, and receptacle jacks
It is also a common antenna connector, especially for vehicle-mounted and rapid deployment radio devices as it is larger and heavier than other types of antenna connectors like SMA and TNC. Its size is also what often necessitates the need for an adapter. As a larger connector, not all radio devices have the room to accommodate N-type connectors, so adapters can facilitate the connection of an N connector antenna to a smaller caliber connector.
When connecting an N-type connector adapter, consideration must be made to the electrical specifications and ratings of the connector type on the other end of the connector. Though the connector adapter will be impedance matched, the voltage rating, frequency range, and other parameters may differ and need to be accommodated.
Key applications for the N-type connector adapter
N-type connector adapters are likely to be needed in the many civil, defense (radar and Satcom), and industrial applications.
- Instrumentation: Their robust panel mounting and heavy caliber yet precision cable assemblies mean that they are of particular use in instrumentation or testing and measurement applications. Between-series N connector adapters can be used to connect miniature connector cabling, antennas, and radio devices to a larger and more resilient panel-mounted and benchtop N connection that will withstand repeated connection and disconnection without loss of performance.
- Radio devices: Both in-series and between series N-type connector adapters can support seamless multi gigahertz connectivity in a wide range of radio devices. The range of conformations available, including jack-to-jack and plug-to-jack means that cabling and N-type connector antennas for broadcast equipment can be readily installed via alternate connectors.
- Wireless Local Area Networking: As a larger, hand-tightened 50 Ohm connector, the N connector is increasingly prevalent in consumer-facing wireless networking. The connectors weatherproof connection is also of use in outdoor antenna and base station installations. High-quality nickel-plated (corrosion-resistant) brass bodies and contacts on both sides of the connector ensure sound electrical performance needed for networks with high data throughput.
- Lightning surge protection: The voltage rating of the N-type connector means that is the connector of choice for protecting cellular and wireless networking antenna installations from damaging voltage surges caused by lightning strikes. N connector adapters can also be used to integrate lightning surge protectors so that they can be connected to miniature and even micro connectors where necessary.
Frequently asked questions
How is an N-type connector attached to coaxial cable?
Making a reliable and secure N connector termination on coaxial cable requires the following tools and equipment:
- An N connector with the connector sleeve
- Coaxial cable
- Cable cutter
- Coaxial cable stripper
- Crimp tool
- Utility knife
- Heat shrink
- Firstly slip the heat shrink and connector sleeve onto the coaxial cable.
- Use the coax stripper to strip the outer jacket of the coax cable.
- Carefully peel back the wire braid of the coax to expose the inner dielectric, being careful not to unravel it.
- Cut away the dielectric, taking care not to damage the inner conducting wire. Use the connector as a guide to determine the amount of dielectric to be removed.
- Place the brass pin of the N connector over the connecting wire, ensuring that it fits snugly against the cut back dielectric (no more than 0.18 inches / 4.76mm should be exposed).
- Crimp the brass pin to the coax conducting wire while holding it in place. Check for a solid crimp.
- Place the connector body onto the cable, ensuring that the pin is in line with the connector’s face.
- Slide up the coax braid and connector sleeve over the connector. Trim off any excess braid.
- Crimp the connector sleeve to the connector.
- Cover the connector sleeve with the heat shrink and use the heat gun to shrink to size.
What is the best coaxial cable for the N connector?
Despite its large size, N connectors are a versatile partner for a range of coaxial cable types including:
Radio Guage (RG)
What is a Tee connector?
A T-connector can connect three coaxial cables. The connector points may vary in gender. They can be used to connect two antennas to a single feed line or split radio frequency energy from the feedline into to divert it to separate radio frequency circuits or devices.
Summary in Conclusion
N-type connector adapters are necessary for a broad range of radio frequency circuits and wireless networks due to the unique specifications of the N connector. For wireless and cellular networking where SMA and RP-SMA connectors predominate, an N-type connector adapter introduces the advantageous features of this rugged connector into otherwise miniature caliber radio frequency circuits.