Spectrum analyzers equipped with directional antennas have been the go-to tools for detecting and locating interference. Conventional swept-tuned and fast Fourier transform (FFT)-based spectrum analyzers are effective for detecting relatively constant signals or observing intermittent signals using the Max Hold feature. However, they tend to exhibit considerable dead time. Compared to conventional spectrum analyzers, real-time spectrum analyzers excel at capturing transient, sporadic, or random signals. SIGLENT real-time spectrum analyzers deliver up to 300,000 FFTs per second, coupled with the persistence mode. The analyzers support multidimensional observation of complex transient signals through diverse display modes such as Density, 3D, Spectrogram, and PvT. They also support waveform replay of up to 125,000 frames and incorporate frequency mask triggering. These features are particularly suited for measuring specific signals of complex, dynamically changing spectrums. The analyzers can trigger and record in-phase and quadrature (IQ) signals before and after signal events within a specified frequency range, enabling subsequent replay and analysis.