This notch would gradually move across the displayed frequency plot and was virtually invisible on the Rigol analyzer. I believe it had something to do with the TFT display sync signal. In Figure 8, I managed to freeze part of that sweeping signal, which shows up as a downward notch in the emission (circled).ДЇigure 8 вЂ“ The sweeping signal was captured as it slowly moved from right to left using the BB60C analyzer (circled). In fact, there was a periodic signal sweeping slowly from right to left (blue-colored trace), that was difficult to detect using the Rigol. With persistence turned on, the Signal Hound reveals a lot more activity around the central portion of the frequency scan. I scanned around with the probe to find the largest average emission profile and then left it there during the comparison measurements.ДЇigure 6 вЂ“ The emission profile of the STM32-F4 Controller as measured with the Rigol DSA815.ДЇigure 7 вЂ“ The emission profile of the STM32-F4 Controller as measured with the Signal Hound BB60C.ДЄs you can see, comparing Figures 6 and 7, we get virtually the same spectral profile. The primary clock frequency is 8 MHz, which gets unconverted to the 180 MHz processor clock.ДЇigure 5 вЂ“ Measuring the near field emissions of the STM32-F4 embedded controller using a Beehive Electronics H-field probe.ДЄs a quick check, IвЂ™ll compare the spectral profile of this board between my Rigol DSA815 and the Signal Hound BB60C. This is an evaluation board with STM32F-series microcontroller, built-in 2.4-inch TFT display and 64 MB of SDRAM.

One of the first things I tried was to measure the near field emissions of my ST Microelectronics STM32-F4 вЂњDiscoveryвЂќ embedded controller. In Part 2, weвЂ™ll show you some actual measurements and several screen captures. In Part 1 of this review, we discussed the basic architecture, specifications and controls of the Signal Hound BB60C real-time spectrum analyzer.

Dsa815 spectrum analyzer colors mea