RF Coax Connector Guide

June 7, 2018 at 8:00 AM

 

When transmitting radio frequencies over cable, coaxial cables are a perfect fit. With shielding to efficiently carry radio signals, there is a coaxial cable for everything – from cable television to Wi-Fi to industrial and scientific measuring instruments, and every application in between. To maintain the frequency flow and shielding effect, the cables need to be joined by coaxial connectors. These connectors are small but are necessary to transmit signals and they need to match the specifications of the coaxial cable. For your convenience, we’ve compiled a guide to the most popular connector types.

  

BNC

 

BNC (Bayonet Neill-Concelman) connectors are one of the oldest connector types. They are round with a slotted mating collar and have a bayonet mechanism that is quick-fastening, secure and quick to disconnect. BNC connectors are used with coaxial cable in wireless antenna, television, radio, video, RF electronics and test instrument applications. These connectors are available with 50 or 75 Ohms of impedance. They are usually limited to a frequency of 4 GHz, but that can be increased with higher-quality models.

 

Type-N


 Type-N, or N-Type, connectors are the largest RF connectors and are an ideal high-performance option. They are typically used with antennas, communications equipment, power transmitters, receivers and in general RF applications. Type-N connectors are typically rated up to 11 GHz, with higher powered models capable of performance of up to 18 GHz. They have a threaded coupling mechanism and are offered with 50 or 75 Ohm impedance.

 


TNC

 

TNC (Threaded Neill-Concelman) connectors are similar to BNC connectors except that instead of a slotted mating collar, they are threaded and screw-down to connect. When using BNC connectors, noise is frequently introduced into the transmission signal because if the bayonet fastening. TNC connectors solve that problem by screw-down connector, which allows them to perform better and at higher frequencies than BNC connectors. TNC connectors have an 11 GHz frequency limit and deliver 50 Ohm of impedance. TNC connectors are also available with reversed polarity (RP-TNC) which makes it more difficult to attach high-gain, professional-grade antennas to commercial-grade equipment.

 

  

SMA

 

The SMA (Sub-Miniature A) is a much smaller RF connector, approximately half the size of a BNC connector. With a diameter of 6.24 mm-7.9 mm, this connector is ideal for RF connectivity between microwave filters, oscillators, mixers, attenuators and boards. These connectors are rated up to 18 GHz, provide 50 Ohm of impedance and have a threaded coupling for a secure connection. Like RP-TNC connectors, reverse polarity SMA (RP-SMA) connectors were also designed to make it more challenging for consumers to connect larger, more powerful, and potentially illegal, antennas.

 

SMB

 

Last, but not least on our list, is the SMB (Sub-Miniature B) connector. With a diameter of only 2.2mm-3mm, these are even smaller than SMA connectors, and are small enough to be used with equipment for inter-board or assembly connections. SMB connectors are generally used in GPS, telephone and CATV applications. They use a snap-on fastening system for easy mating and un-mating, are offered with an impedance level of either 50 or 75 Ohm and have a frequency limit of 4 GHz.

 

 

Readers’ Choice -Top Blog Posts of 2017

December 21, 2017 at 8:00 AM

 

As we wrap up another year, we’d like to take a moment to look back on some of our most popular posts. We pride ourselves on providing informative content for our readers by covering a range of wired and wireless technology topics. We sincerely hope that you enjoyed reading our posts as much as we enjoyed writing them and in case you missed anything, here’s a highlight reel of the most popular posts of 2017.

 

 1.       Cable Showdown: Cat6 vs. Cat6a

 

It’s a Cat eat Cat world out there and Cat6 and Cat6a are two of the most popular standards for Ethernet cables. So, how do you decide between the two? One may work better than the other, depending on your application. To help you pick a winner, we compared them side-by-side for a showdown of category proportions. To see how each Cat fared, read the post.

 

 

2.       White-Space Wi-Fi 802.11af

 

Waste not, want not, seems to be a growing way of life for many people these days, and that theme will soon apply to the Wi-Fi spectrum as well. The IEEE standard 802.11af, also known as white-space Wi-Fi or White-Fi, will utilize the unused space in the TV spectrum, the TV white-space, to support Wi-Fi networks. Read the post to find out how it all works.

 

 

3.       OM5 – The Next Generation of Multimode Fiber

 

OM5 was chosen to be the new standard for cabling containing wideband multimode fiber in the 3rd edition of the ISO/IEC 11801 standard. The acceptance of this standard is a milestone for the fiber cabling performance category because it extends the benefits of this revolutionary multimode fiber within connected buildings and data centers worldwide. To find what you need to know about OM5, click here.

 

 

4.       802.11ax – The Next Big Thing

 

The IEEE will be adding to its 802.11 series of standards again with the launch of 802.11ax. 802.11ax is under development and will pick-up where 802.11ac left off by taking MIMO to the next level with MIMO-OFDM. This next big upgrade to Wi-Fi networks might not make its debut for a couple of years, but here’s a look at what’s coming.

 

 

5.       75 Ohm vs. 50 Ohm – Coaxial Comparison

 

Ohm may sound like something you’d say while meditating, but when it comes to coaxial cables, it is actually a unit of resistance. Ohms measure the impedance within the cable. Impedance is resistance to the flow of electrical current through a circuit. To see how 75 Ohm and 50 Ohm compare, read our post.

 

 

75 Ohm vs. 50 Ohm - Coaxial Comparison

September 21, 2017 at 8:00 AM

 

Ohm may look like something you’d say while meditating, but when it comes to coaxial cables, it is actually a unit of resistance. Ohms measure the impedance within the cable. Impedance is resistance to the flow of electrical current through a circuit.

 

A smaller Ohm measurement equals less impedance. This means that a 50 Ohm cable has less resistance to the electrical current than a 75 Ohm cable. Though there really isn’t a "good" or "bad" level of impedance, it just depends on what is right for your application.

 

75 Ohm cables are the standard coaxial cables used throughout the home, they are often pre-wired into many homes and businesses. The primary application for 75 Ohm cables is transmitting video and audio signals. They are used to connect televisions to cable and satellite receivers and internet routers. These cables are ideal for smaller applications where a signal is transmitted up to 50 feet before the signal is repeated by an active device.

 

50 Ohm coaxial cables are mainly utilized in wired and wireless networks to relay data signals. Low-loss 50 Ohm cables are used for transferring RF signals in wireless networks. For commercial installations, 50 Ohm cables typically have the advantage over 75 Ohm because they perform better (less attenuation than 75 Ohm) over longer distances of more than 100 feet and over larger areas. The disadvantage of 50 Ohm cables is that they are much thicker and use larger connectors. Typical applications for 50 Ohm cables include GPS, cellular and test and measurement applications.

 

To recap, for the lowest impedance of electrical current, 50 Ohm is the best bet. 75 Ohm cables lose almost two times the amount of dB gain every 10 feet when compared to 50 Ohm cables.

 

Also, keep in mind that the 50 Ohm and 75 Ohm ratings only refer to the cables themselves and they can be mixed and matched with cables and connectors in any other system.

 

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