Military component, antenna and battery testing

Why is resilience against coexisting and jamming becoming more important for secure radio designs?

Secure Radios operate in a congested (e.g law enforcement in an urban area) and even contested environment (e.g. military in a mission scenario). To analyze and optimize secure radio designs against these threats coexistence tests are carried out in order to prevent losing communication performance due to specific interference signals caused by other transmissions.

This is especially important for public safety radios, as they operate in very dense and busy spectrums, where secure waveforms need to coexist with commercial waveforms such as radio broadcasting, WiFi, Bluetooth, LTE between other. For these tests over the air instruments are used to generate digital or analogue spurious signals and verify how the receiver manage the distorted signal.

In the traditional military or law enforcement analog radios, antenna design was relevant, but not critical, as they were mostly oversized. New radio designs, waveforms and digital communications technologies with smaller designs require new advanced antennas such these known as MIMO, whose exquisite design mandates very exhaustive testing. This kind of tests, needs specific antenna chambers, accurately setup for the device under test and realistically emulating the environment where the radios will be operating.

There are many components in a software-defined radio board: clocks, amplifiers, filters, converters, memories, data buses, etc. All these components need to be selected and integrated to ensure that power and signal integrity is kept within acceptable margins. Among others, crosstalk between active and passive components, system clock verification or PLL SerDes performance are tests carried with instruments such as oscilloscopes, vector network analyzers, phase noise analyzers and voltage-controlled oscillators.

To evaluate battery performance of a mobile secure radio, for instance a military handheld radio, developer need to understand the power level of the battery, the power consumption of the radio system and status of the power management system in particular test cases.: For these cases, the objective of the conducted test is to determine how the power from the battery is managed and delivered to the system.

The best approach is to emulate the battery in different start conditions, automate performance tests and evidence how the power is drained compared to the specified or expected scenario. The best way to proceed is connecting cell emulator instruments (like the R&S®NGM200) into the power source of the DUT. These instruments can simulate real behavior of battery drainage for up to two cells, and more instruments can be connected in parallel and series in order to emulate as many cells as desired.

Finally, external instrument remote control software can be used to automatically run test cases to stress the battery management system with scenarios where the BMS needs to proof its good performance.