Radio Frequency (RF) & Wireless Design

There are many types of RF connectors depending on the cable medium that you are attaching to and also the impedance (in ohms) of the connection.

https://en.wikipedia.org/wiki/List_of_RF_connector_types

The most common form of RF cable is the coaxial cable, since the impedance is controlled linearly and that the Electro-Magnetic (EM) field is contained between the core and shield.

https://en.wikipedia.org/wiki/Coaxial_cable

The most basic standard for coaxial cables is the 'Radio Guide' or RG types that are listed in this table ;

https://en.wikipedia.org/wiki/Coaxial_cable#Standards

Notice that the impedance for most cables is around 50 ohms, at 50 ohms, at 75 ohms, and a few rarer ones at around 93 ohms and 125 ohms. Most typical systems are 50 ohms and also there is cable TV at 75 ohms.

An RF cable is chosen at the design stage to 'match' the source (transmitter or receiver) to the antenna for the most basic systems.

https://en.wikipedia.org/wiki/Impedance_matching

The reason for this is to accomplish Maximum Power Transfer and there is a theorem for this :

https://en.wikipedia.org/wiki/Maximum_power_transfer_theorem

The cable type will determine the amount of loss (in dB) that the signal will be attenuated. However attenuation is based upon the frequency that is being passed thru the cable, therefore your performance will vary.

Older connectors are typically bayonet type or screw on. Bear in mind that even connectors suffer from attenuation and should be chose carefully too. One of the most common instrument connector is the BNC connector. This connector is not that good for high performance compared to the SMA types, but is good for a general purpose fast connecting RF connector.

https://en.wikipedia.org/wiki/SMA_connector

More recently micro coax (MCX) and mini-micro coax (MMCX) has emerged with its connectors which are typically used on Bluetooth, Zigbee, WiFi and other small modules. U.FL, IPEX, IPAX, IPX,[1]AMC, MHF and UMCC are other types.

https://en.wikipedia.org/wiki/MCX_connector

https://en.wikipedia.org/wiki/MMCX_connector

https://en.wikipedia.org/wiki/Hirose_U.FL

These small connectors have varying cable sizes and assembled heights, therefore choosing an MCX connector should be performed carefully !