Difference between a multiplexer and Power Divider

Multiplexers and Power Dividers are also useful tools for increasing the number of antennas that can be connected to a single reader port. One of the key advantages is that by sharing costly hardware, the expense of a UHF RFID programme can be reduced. We clarify the variations and what to consider when choosing the best computer for your application in this blog post.

What is the difference between a multiplexer and a de-multiplexer?

We'll quickly go over the general function of multiplexers (mux) and de-multiplexers to help you understand what an RFID reader Multiplexer is (de-mux).

A multiplexer is an electronic system that selects one of several input signals and sends it to an output.

A demultiplexer is a system that sends a signal from one input to one of several outputs.

Switches are required to select the inputs and/or outputs in both multiplexers and demultiplexers. Since these switches are operated, mux and de-mux are called active devices.

What is an RFID reader multiplexer, and how does it work?

A RFID reader multiplexer incorporates the features of a mux and a de-mux. It has one input/output port and a variety of output/input ports. An RFID reader is normally connected to a single port of a mux/de-mux, while the other ports are used for antenna connections.

It either sends signals from the RFID reader's port to one of the output ports or receives signals from one of the input ports and sends them to the RFID reader's port.

The signal switching between the ports and the switch timing are done by a built-in switch.

A system that divides power is known as a power divider (splitter). The input power is split into two outputs by a 2-port power divider. In the output ports, the power is halved in magnitude.

The power divider is called a power combiner when used in reverse

The RFID multiplexer allows multiple antennas to attach to a single RFID reader port. Regardless of the number of ports in a mux/de-mux, the magnitude of the signal switched is unchanged.

An 8-port RFID multiplexer, for example, will transform a 4-port RFID reader into a 32-port RFID reader in this manner.

Some businesses refer to their mux as a hub.

Regardless of the number of ports, a mux can suffer continuous power loss across them. Losses per port would be the same for a 4-port, 8-port, and 16-port mux.

Depending on the number of available ports, a power divider will divide the power into 12 or 14. As the number of ports increases, each port experiences a greater power reduction.

A mux is a computer that is in operation. To function, it needs DC power and control signals.

A passive system is a power divider. It does not need any additional input besides the RF input.

In a multi-port mux, not all ports are switched on at the same time. Between the ports, the RF power is switched. Just one attached antenna will be switched on at a time, and the switching is quick enough that the antennas will not skip a tag read.

In a multi-port power divider, all of the ports receive the same amount of power at the same time.

The ports are isolated to a very high degree. This is important to prevent antenna-to-antenna cross-tag reads. Isolation is typically in the 35 dB range or higher.

When compared to a Mux, port isolation is a little less. Port isolation is typically around 20 dB or higher. Cross-tag reads could become a problem.

In a power divider and an RFID mux, what are the losses involved?

Regardless of the number of ports, an RFID mux will have losses in the range of 1 to 1.5 dB. (4, 8 or 16). This loss will be triggered by the mux's RF switches and other logic. The loss is known as insertion loss, and it is consistent across all RFID multiplexer ports.

The inherited insertion loss and the splitting loss are two losses that are correlated with a power divider. As the number of ports grows, the insertion loss grows as well. The type of power divider manufacturer also influences insertion failure. The insertion loss of a standard 3-port, 4-port, 6-port, 8-port, and 12-port power divider is 0.8 dB, 1.1 dB, 1.5 dB, 2 dB, and 3 dB at each port, respectively. Furthermore, power loss during the power split is 4.7 dB, 6 dB, 7.7 dB, 9 dB, and 10.7 dB for a standard 3-port, 4-port, 6-port, 8-port, and 12-port power divider, respectively.

And for those who are new to RF, a Mux will not be a challenge, and it is better to use.

The use of a power divider could result in a violation of the rules and regulations. As an example, consider the following:

Assume you're in the United States and you've hooked up a 6 dBi antenna to an RFID reader. With a cable loss of 1 dB, the reader power is set to 31 dBm. This configuration produces 4 W EIRP, which is the maximum permitted power for UHF RFID systems in the United States. The Federal Communications Commission needs this (FCC). You are now under the legal limit, and you have not violated the rule.

Let's assume you decided to use a 2-way power divider to connect two antennas that were right next to each other. You might think you've connected two x 6 dBi antennas to a power divider, but the beams of those two antennas will combine to give you an 8 dBi gain. Since you are now producing 6.3 W EIRP, you will be breaking the rule.

Can I use a power divider to combine a near-field and a far-field antenna?

If the near-field antenna is a pure near-field only antenna, the beams of the two antennas can not be able to combine. Some loop antennas with far-field gain are available on the market as near-field antennas. When a power combiner is used, these antennas can have an effect on the overall RF beam. The realised RF beam can be unpredictable, and it can also cause null zones.The only way to prevent this is to keep the antennas separated by about 2 feet.In the majority of cases, a multiplexer is suggested.

Jordan is a Managing Editor working in California. She writes about the past of the internet, consumer-facing technology, and social media. Jordan is the programming director for the world-famous Disrupt conference and flagship event. You may recall her from her appearances as the event's host and moderator of panels and fireside chats.She is now working as a Managing Editor for Eravant Tech company.