Hub Fan-out Transceiver Test Systems for Radio Testing

A hub fan-out transceiver test systems is constructed as a star matrix with all ports connected through a central hub. The star configuration limits the number of paths in the matrix to be equal to the number of ports. This type of construction allows for radio-to-radio communication testing. The attenuators can be remotely controlled to simulate static or dynamic environments.

With the hub configuration, there is a single programmable attenuators between the port and the hub. Two 4 port example block diagrams are listed below the table. The hub fan-out design is the most basic of JFW’s transceiver test systems. It is also the least costly since it uses a minimum number of internal RF components to construct the matrix.

By including RF switches into the construction, you may have multiple hubs. Each port will have an RF switch that is used to select between hubs. The isolation of the switches allows the hubs to act as separate networks.

Please contact us or use our Inquiry Form if you do not find a model that meets your requirements. JFW does not charge NREs for new test system models.

JFW Model #	Impedance	Configuration	dB Total	dB Step	Frequency Start	Frequency Stop	Control	RF Connectors
50PMA-029	50 Ohm	8 Ports with 3 Hubs	63 dB	1 dB	DC	2000 MHz	Ethernet, RS-232	SMA
50PMA-031	50 Ohm	6 Ports with 2 Hubs	63 dB	1 dB	30 MHz	3000 MHz	Ethernet, RS-232	SMA
50PMA-045	50 Ohm	4 Ports with 1 Hub	127 dB	1 dB	DC	1000 MHz	Keypad, Ethernet, RS-232	N, SMA
50PMA-073	50 Ohm	8 Ports with 2 Hubs	63 dB	1 dB	30 MHz	2000 MHz	Keypad, Ethernet, RS-232	N, SMA, TNC
50PMA-078	50 Ohm	12 Ports with 2 Hubs	127 dB	1 dB	DC	500 MHz	Keypad, Ethernet, RS-232	N, SMA
50PMA-099	50 Ohm	16 Ports with 6 Hubs	63 dB	1 dB	30 MHz	2000 MHz	Keypad, Ethernet, RS-232	SMA

4 Port Hub Fan-out System w/ 1 RF Hub

Below are two diagrams. The left diagram shows how all ports are connected to each other. The right diagram shows the attenuator addressing for each path. Each port has its own individually controlled programmable attenuator. A signal transmitted into port #1 is received at the other ports at the following signal levels:

Rx at Port #2 = (Tx into Port #1) – (Attenuator #1) – (loss of Hub) – (Attenuator #2)
Rx at Port #3 = (Tx into Port #1) – (Attenuator #1) – (loss of Hub) – (Attenuator #3)
Rx at Port #4 = (Tx into Port #1) – (Attenuator #1) – (loss of Hub) – (Attenuator #4)

Each programmable attenuator in this example can be varied from 0-127 x 1dB to achieve dynamic RF signal fading between ports. The RF hub is designed with an internal star configuration. This star configuration allows all ports to be simultaneously connected to each other with equal port-to-port loss.

4 Port Hub Fan-out System w/ 2 RF Hubs

The below block diagram shows an example of a 4 port hub test system with two RF Hubs. The two RF hubs are used to create two isolated groups of radios. Each port can be connected to either hub by setting the 1P2T RF switches. Once connected to a hub, each programmable attenuator can be varied from 0-127 x 1dB to achieve dynamic RF signal fading between ports.

Custom Models

The models listed in the above table showcase some of our standard transceiver test systems. Email us your specific requirement to sales@jfwindustries.com. We will respond with a ROM (rough order of magnitude) quote in 1-2 days.

Remote Commands

The transceiver test system models are available with Ethernet/Serial remote control.  Our current generation of Ethernet/Serial firmware is called 3.x.x firmware. It features easy to use ASCII formatted remote commands. Use our Ethernet Test Box to demo the 3.x.x firmware.

Test Software

JFW provides a GUI test program with all Ethernet and RS-232 controlled test systems. The test software for transceiver test systems has all of the remote commands built in for easy testing. In addition to the remote commands, the GUI test program has additional functionality such as keypress, handover, and indefinite handover. Several of our sample test programs are available online.