A NETWORK ANALYZER QCM SHIELD
Just like with the Q-1, the primary component of the openQCM NEXT electronics is a network analyzer. This device passively interrogates the quartz sensor by sweeping around its resonance frequency.
The actuation signal is produced by the AD9851 DDS/DAC frequency synthesizer, and the resultant output signal is assessed by the AD8302 gain and phase detector. This detector is capable of measuring both the gain (magnitude ratio) across the quartz crystal and the phase difference between the actuation and output signals.
Analyzing the gain curve enables the characterization of the sensor, allowing simultaneous measurement of the resonance frequency and quality factor. A key advantage of this measurement scheme is its ability to measure quartz sensor parameters in isolation, eliminating the influence of external circuitry.