Vector Measurement of Nonlinear Responses Generated by SAW/BAW RF Devices Using Lock-in Amplifiers

This paper describes a development of vector (amplitude and phase) measurement system for detecting nonlinear responses generated by SAW/BAW RF devices. The system employs universal lock-in amplifiers instead of unique equipment such as the Cross-Domain Analyzer (XDA). As demonstrations, the second- and the third-order harmonic responses generated by a one-port SAW resonator whose resonant and anti-resonant frequencies are 833.8 and 862.8 [MHz], respectively, are measured. The measured amplitude and phase by the proposed method coincide with those measured by the XDA with reasonable accuracy. This result demonstrates that the proposed method can measure feeble nonlinear responses from the SAW/BAW RF devices as vector data, with at least comparable SNR with those measured by the XDA. The proposed measurement system provides practical tools to acquire the complex amplitude of nonlinear responses from the SAW/BAW RF devices.