What are the Benefits of RF over Fiber Technology?

RF over fiber is the method of converting a radio wave into light by modulating the intensity of the laser. Fiber optic cable has many benefits over traditional copper coaxial cable including lower loss, EMI immunity and simple installation.

In this video, Richard Jacklin (Director of ViaLite Communications) explains the benefits of RF over fiber, how the technology works and where it can be used.

For more information, read our guide on RF over fiber technology.

 

Video Transcript

Hello, my name is Richard Jacklin and I’m the Director of ViaLite Communications. ViaLite is a manufacturer of RF over fiber technology and platforms and in this short video I’m going to explain what RF over fiber is as a technology and how it’s used.

 

What is RF over fiber?

Okay, so let’s start at the beginning. What is RF over fiber?

Well, in a short sentence, it’s really a coaxial cable replacement product. So we’re all familiar with RF coax cable. Typically, it’s a 50 Ohm or 75 Ohm product. We see various different ends. This is a BNC type connector that’s quite commonly used. It’s used everywhere, in the home, in industry and it’s a great product. It’s cheap, readily available, but as you go up in frequency, up in the spectrum and as you go longer in length, you tend to get longer and bigger losses with this type of product. And for short distances it’s not a problem, but for longer distances, this can become a problem for users.

So the alternative to that is a product called fiber optic cable. We all know about this. It’s in the street and it’s now connected to many homes around the world. This is a great product. In terms of losses it has a loss capability of a magnitude less than the humble coax. So we can go kilometers, or tens of kilometers with this where, with coax, you might be limited just to tens of meters.

Fiber optic cable also brings with it lots of other benefits as well. So it’s immune to high energy electromagnetic interfering-type environments because it’s kind of a plastic and glass product. It means that it provides isolation from things like lightning strikes through to sensitive equipment. You can see here it’s a small, it’s a lightweight product. It’s easy to install, it’s quite cheap and when we actually put a radio signal over it, we actually get very good dynamic range, great phase and frequency response.

So really, RF over fiber is built on using the benefits of fiber optic cable.

 

How does RF over fiber work?

So let’s dive a little bit deeper now into RF over fiber and how it works.

We’ve talked about the bit that connects it in between, which is our fiber optic cable. So the other parts of RF over fiber is actually made of two parts. We have a transmitter which is the RF and the electrical conversion into optics, and at the other end, we have the receiver, which is the optical back into RF and electrical. Just to sort of demonstrate that a bit better. This is actually a transceiver product. So it has a transmitter and a receiver on the same card, the PCB card that we have here.

On the lower section here, we have the transmitter. Just behind this metal collar is a laser and actually that is the core component that does the conversion from the RF electrical energy into optics. And in RF over fiber, we intensity modulate that laser to actually move that RF energy into the optical world. On the other side, on the receiver side we have this product here, you may be able to see it. This is a photodiode and that’s the core component that moves the optical energy back into RF.

You can see that on this particular PCB, there’s other capabilities. We have dip switches here, which can control things like gain or automatic gain control, or if you need to put power onto the RF cable. This type of product is also chassis-based, so it connects into a chassis and a controller which is typically SNMP enabled.

RF over fiber though can come in lots of other different form factors. So this type of product here is a single receiver or a single transmitter in a much smaller, self-contained unit. So lots of different ways that this can be formatted.

 

How can RF over fiber be used?

So as I previously mentioned, in RF over fiber we use intensity modulated lasers. And what that actually gives us is a modulation agnostic conversion capability. So it actually enables us to use this type of technology across a very very wide range of wireless and radio applications.

So you’ll see RF over fiber used very heavily in satcom, connecting the dishes. Particularly gateway sites through to the network equipment rooms. We use it in broadcast, connecting wireless cameras and microphone systems back to the production desk. For GPS and GNSS systems, taking those signals which can normally be seen only outside to indoor locations such as underground transport for instance. We use lots in aero and defense applications, maritime, radar. Basically, the list is pretty much endless.

So if you’re interested to see more around the applications and use cases for RF over fiber, you’re very welcome to visit our website you can find out more about those and also about our products. Anyway, hopefully this video has been helpful and look forward to seeing you again soon. Thanks.