Many common connector formats, such as D-type connectors and other multiway connectors, are made up of a series of pins connected in parallel. RF connectors are usually very distinctive and have a variety of distinct features. Screened: Since radio frequency signals can radiate, it's crucial to avoid unwanted signals from being picked up. As a result, RF connectors by their very design continue to screen the coaxial cable. Circular shape: RF coaxial connectors must preserve the coaxial aspect of the cable for which they are used, because they are circular. As a result, they have a central pin for the coax cable's inner conductor and an outer connection around the inner conductor for the cable's outer conductor. Characteristic impedance: A feeder's or coaxial cables characteristic impedance is important. Power will be mirrored back to the source if there is a mismatch. It's also vital that the RF coaxial cable connections have the same characteristic impedance as the cable. If not, a discontinuity would be imposed, resulting in losses, but this is unlikely to affect the majority of installations using frequencies up to around 250 MHz The majority of RF connectors are 50 ohms, but other impedances, such as 75 ohms for some domestic applications and other impedances for data transmission, are also available. Males are usually used for coaxial cables, while females are fixed: Unlike other types of connectors, where it is normal practice to use the female connector to supply signal or power because it is more protected and less likely to be shorted out, this is not always the case for RF connectors. Here, male connectors on leads are more common than female connectors on equipment, though the traditional connector convention may be used in a few cases. Types of cables: Since various types of coaxial cable have different dimensions, different coaxial connector variants are available to suit a specific cable form. It is vital to use the correct RF connector variant with the required coaxial cable; otherwise, the connector may be difficult to fit, if it can be done at all, and even if it can, the connection between the coaxial cable and the RF connector may be insufficient.
One of the most commonly used RF connectors today is the BNC coax connector. It's simple and straightforward to use, and it provides excellent results. From oscilloscopes to audio generators, power meters to feature generators, the BNC connector is used on test equipment. In reality, BNC connectors are commonly used in applications that require coaxial or screened cable, particularly in RF applications.
The BNC connector has a number of functionality. Its use of a bayonet fixing is one of its most prominent mechanical features. This is particularly useful because it prevents the cable from being inadvertently cut if it is pulled slightly or pushed repeatedly.
The BNC connector is also known as a constant impedance connector. This means that the characteristic impedance is the same in the connector. Characteristic impedance is a concept used to characterise the impedance of coax cable. As a result, RF signals travelling over coax will not encounter any impedance changes as they pass through the BNC connector. This is especially important for RF applications because it means less reflections and less loss. The requirements of the BNC connector vary from one manufacturer to the next, so it's always a good idea to double-check that the part you're buying is right for the job. There are, however, a few guidelines that should be followed. There are two basic types of connectors: 75 ohm 50 ohm
The 50 ohm variant of the BNC connector is the more popular of the two. The BNC connector is frequently specified for use at frequencies up to 4 GHz, but it can be used at frequencies up to 10 GHz if specific high-quality models designed for that frequency are used. However, it is advisable to carefully examine the specification. The different varieties of BNC connectors come in a wide range of options. Not only are there sockets and plugs, but there are also adapters and other accessories such as attenuators. These coax connectors are designed to accept only the specified impedance, but can also take advantage of certain coax cable configurations. So, in this way, all of the internal piece parts are compatible with the coaxial cable that is used. As a result, it is necessary to include the BNC plug in the cable in order to use it. The options for cable format are reasonably flexible, but for most applications, the right cable format should be selected. In addition to this, there are variants that are parallel to the base, and variants that are perpendicular to the base. Among these, the straight connectors are the most widely used, though there are also right angled connectors that are used when the cable leaves the plug at right angles to the centre of the connector. In many applications, these work well because the cables have to leave the connector in this manner to ensure cables are neatly arranged, or where space is at a premium. To the detriment of noise reduction, right-angled connectors have a marginally higher level of loss than their straight through counterparts. This may not be a significant issue for most applications, but for frequencies that are near the operational limit of the connector, there may be a slight difference. As well as being offered in various colours, the socket/female BNC connectors come in different varieties as well. A common type of BNC connector, found in set-top boxes, consists of a panel-mounting assembly with a single coaxial connection at the centre. Finally, a single nut is used to bolt the panel to which the connector is attached, after which the earthing is done. The use of large washers allows for an earth connection to be made directly to the connector. A number of these connectors may additionally use four nuts and bolts to affix them to the panel. For low-frequency applications only, these arrangements are appropriate. They are not suitable for RF applications. Where the impedance needs to be matched and a full screening must be done. connectors that are installed into bulkhead mounting positions for coaxial cable
John is a straightforward, intelligent techie with a passion for blogging. He loves delving into the inner workings of the Coaxial High-Pass Filters from Monday to Thursday. He is a little more reserved on weekends, though, and simply enjoys spending time with his dog.