*This post first appeared on the Tektronix blog.*
Modern technologies such as MIMO require the need for wide bandwidth, phase coherent, multi-channel analysis. Antenna elements in a MIMO radar system operate independently to cover a wide, often 180-degree, field of view without the need for directivity adjustments. This significantly improves scan times. The MIMO radar employs time, frequency, or coding techniques in each transmit signal to differentiate them in the receiver element to extract target properties.
A wideband oscilloscope, such as a Tektronix DPO70000SX or MSO/DPO70000DX Series oscilloscope, is an ideal instrument because it is designed specifically for wide bandwidths and phase coherency. Paired with SignalVu VSA software version 5.3 for multi-channel controls and analysis, the resulting test system is an excellent choice for validating a MIMO phased array radar because it provides independent settings for parameters such as center frequency, span, and RBW. This is necessary in order to acquire the signals which may have different center frequencies, time slots, or modulation parameters.
Pulse Statistics for Spectrum Analysis
The TDM MIMO radar assigns a time slot for each element. The signal on each channel has a pulse width of one microsecond and PRI of 100 microseconds and slot delay between channel one and channel two is 10 microseconds. With SignalVu software we can see whether the signals generated are aligned correctly to the assigned time slot or not. Using SignalVu’s time overview display to configure the analysis time and spectrum time parameters we can examine the starting position or the start time of the pulses on each channel to determine the time delay between them. Additionally, we can measure the PRI of both channels to determine if this delay is consistently maintained or not. A pulse statistics display allows us to observe the time trend and measurement statistics to see how the PRI varies across pulses over time. The pulse table provides information about the absolute delay between channels or time slot, while the time trend reveals how this delay is maintained over time.