Wireless Connectors Guide

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A pigtail (photo), is a short cable needed to connect the DIY antenna to a laptop or desktop wireless card and/or access point. A pigtail (sometimes called a laptop adapter cable) is a short length of microwave-friendly coaxial cable with connectors on both ends. It needs to be short because coaxial cable is very lossy at microwave frequencies, and the loss is proportional to the length of the cable.You can make you own (see below), but unless you have experience soldering small connectors to coax, spend you money on a ready-made pigtail. Since the DIY antenna uses a standard N-Female connector, the antenna end of the pigtail will need to be a standard N-Male connector. Look for quality N connectors, low loss silver-plated with gold contacts, not the cheaper silver contacts. If necessary, you can add a PCMCIA or USB adapter to your laptop that will accept the other end of the pigtail. Look for cards/adapters with external antenna connections!

Sex, Connecting and Disconnecting

If you don't understand the reason for using the terms male connector and female connector, ask your parents.

RF and microwave connectors can be easily damaged by mistreatment. As a general rule, if the connectors have threaded sleeves, you should rotate these to tighten, leaving the rest of the connector (and cable) stationary. If other parts of the connector are twisted while tightening or loosening, damage can easily occur. Take into consideration the number of connect-disconnect cycles that a connector pair can tolerate.

Stress Relief to Protect Weak Connectors

Protect your card's RP-MMCX or MC jack by using a manufactured 6-inch RF pigtail. The "stress-relief" pigtail has a RP-MMCX or MC connector at one end and a RP-SMA connector on the other end.

This allows a user to connect to any devices and antennas that support the stronger and more common RP-SMA connector (used by D-Link and others.)

Cable Organization

What happens when you coil copper wire together into a large bundle? You make an antenna which could cause interference which could be a problem with your signals. Your goal in organization is to minimize the times that any cable crosses any other cable. Running all of your cables at 90-degree angles and keeping them to the minimum length possible -to prevent coils- can accomplish this. This will help ensure there is as little interference to the signal path as possible.

Choosing the proper connector

1. Virtually all connectors have a well defined gender consisting of either a pin (the male end) or a socket (the female end). Usually cables have male connectors on both ends, while RF devices (i.e. transmitters and antennas) have female connectors. Devices such as directional couplers and line-through measuring devices may have both male and female connectors. Be sure that every male connector in your system mates with a female connector.
2. Try to minimize the number of connectors and adapters in the RF chain. Each connector introduces some additional loss (up to a few dB for each connection, depending on the connector!)
3. Buy cables that are already terminated with the connectors you need whenever possible. Soldering connectors is not an easy task, and to do this job properly is almost impossible for small connectors as U.FL (photo) and MMCX. Even terminating foam cables is not an easy task.
4. Don't use BNC for 2.4GHz or higher. Use N type connectors (or SMA, SMB, TNC, etc.)
5. Microwave connectors are precision-made parts, and can be easily damaged by mistreatment. As a general rule, you should rotate the outer sleeve to tighten the connector, leaving the rest of the connector (and cable) stationary. If other parts of the connector are twisted while tightening or loosening, damage can easily occur.
6. Never step over connectors, or drop connectors on the floor when disconnecting cables (this happens more often than what you may imagine, especially when working on a mast over a roof).
7. Never use tools like pliers to tighten connectors. Always use your hands. When working outside, remember that metals expand at high temperatures and reduce their size at low temperatures: a very tightened connector in the summer can bind or even break in winter.
8. SMA, RP-SMA, and RP-TNC connectors, are the most common connector types for most all of the popular routers on the market. SMA - The SMA Male connector has threads on the inside and a center pin. RPSMA - The RPSMA connector has threads on the inside and a center socket (instead of the standard pin). RPTNC - The RPTNC connector has threads on the inside and a center socket.

Connector Types

Chess Anyone?

Reverse polarity (RP) connectors have the normal "male" and "female" inner connector parts swapped over so that female contacts are used in the plug connector and male contacts in the jack. Their purpose is to prevent the user from inadvertently plugging in equipment (such as a radio antenna) that differs from the type specified by the manufacturer.

What are SMA, SMB, SMC, MCX and MMCX connectors?

Of these five subminiature connector families, the largest of these connectors is the SMA connector, SMA Male (photo), SMA Female (photo), RPSMA Male (photo), RPSMA Female (photo), which has a threaded interface and is capable of operating up to 26.5 GHz. The SMB connector, smaller in size than the SMA, features a snap-on interface mechanism for quick connect/disconnect capabilities. The SMB operates to 4 GHz in the 50 ohm version, and up to 2 GHz in the 75 ohm version. The SMC connector is similar in size as the SMB, but utilizes a threaded coupling interface for tighter control of the contact and insulator locations, allowing operation up to 10 GHz. The MCX (photo) is approximately 30% smaller than the SMB connector. MCX connectors utilizes a snap-on interface, and operate up to 6 GHz. The MMCX (photo) is the smallest connector available for use with Standard coaxial cables. It is approximately 30% smaller than the MCX connector. The MMCX features a snap-on "C" spring interface to minimize RF leakage, and operates up to 6 GHz.

Connector Table of PC interfaces for external peripherals and connections inside a PC system.

What are RJ-45, RJ-11 and USB connectors? Photos and Descriptions. (photo) Ethernet cable instructions, ethernet cable tips and basic theory when using ethernet cable and RJ-45 connectors are dsescribed at Ethernet Cable: Color-Code Standards.

You made it this far and as a reward I'm giving you a great tip. Home Depot sells a lot of electronics cables right on the same aisle as the extension cords. Everything from RCA adapters to ethernet cables - and mostly they’re really cheap! So the next time you head over there for some generic home repair stuff, check out their cable and connectors selection.

The handbook of hardware pinouts, cables schemes and connectors layouts contains useful information about pin assignments for a variety of devices.