Modern radio technologies such as IoT, TETRA, Smart Metering, MIMO, Car to Car, military communication and many more require new test solutions. Not so much the frequency range, but the classic structure in mobile communication from the sender side to the receiver side was abolished. Modern communication takes place not only vertically but also horizontally. This enables a direct connection between different terminal devices without a network infrastructure. Thus, applications, products or terminal devices of this type sometimes create their own networks, expand the network or pass on information from neighbouring network subscribers.

In order to simulate such structures in a test environment, MTS Systemtechnik has developed radio field simulations of the AIAD-X+ series. The core of these consists of a fully meshed network (see figure below). This makes it possible to connect RF ports to all other RF ports via separate signal paths. Programmable attenuators in each path emulate the signal attenuation to any neighboring cells.

The AIAD-X+ devices offer a number of advantages:

• System can be adapted to specific frequencies or frequency ranges between 30 and 6000 MHz
• Arbitrary scalability from 3 to 33 HF ports
• Combinations or division of ports, e.g. Main + Diversity
• Partially meshed or unbalanced networks are also possible (e.g. only 2 adjacent cells can be addressed or only 2 ports are connected to all others)
• Adjustment of signal attenuation up to 190 dB in 1 dB steps
• Bidirectional transmission
• The systems can be designed for high input powers of up to 50W
• Outstanding isolation between ports of 165 dB
• An indirect isolation* of 75 dB (700 - 3600 MHz / 790 - 5850 MHz) could be achieved by a special circuit design.