The　design　can　measure　and　display　other　parameters　such　as　the　modulation　system　of　the　measured　signal　output　by　the　signal　source,　identify　and　display　the　modulation　mode　of　the　measured　signal,　and　output　the　demodulation　signal.　The　measurement　module　is　composed　of　an　automatic　gain　amplifier　circuit,　a　broadband　amplifier,　a　low-pass　filter　circuit,　a　DDS　signal　generation　circuit,　an　amplification　circuit,　and　a　display　circuit.　The　working　principle　of　the　signal　modulation　measuring　device　is　that　the　demodulated　AM　signal　is　obtained　after　the　spectrum　is　transmitted　by　the　multiplier,　and　the　high-frequency　signal　is　filtered　out　by　the　low-pass　filter　and　amplified　by　the　fixed　gain　amplifier.　After　the　amplification　circuit,　the　output　waveform　is　sampled　by　the　onboard　ADC　of　MSP432E401Y,　and　then　the　fast　Fourier　transform　is　performed　to　obtain　various　parameters,　which　are　finally　displayed　on　the　serial　screen.　©　Published　under　licence　by　IOP　Publishing　Ltd.