Proposal of the frequency measurement method for GHz band crystal units

The paper describes the reproducibility of resonance frequency measurements for GHz band lead-less crystal units for international standards. The paper examines reflection as a new measurement method, which achieves crystal unit reproducibility with accuracy on the level of 10^-6. The admittance circle technique and mid-frequency locus technique are applied as basic measurement methods. The frequency range of the measurement method is 150 MHz to 3 GHz. The admittance circle technique is applied to crystal units of M>2. The mid-frequency locus technique is applied to crystal units of M≤2. Frequency measurement reproducibility for 600 MHz, 1.8 GHz, and 3 GHz crystal units is about ±1×10^-6.