Overview
IEC TS 61994-1:2007 is a Technical Specification from the International Electrotechnical Commission (IEC) that provides a standardized glossary of terms and definitions for piezoelectric and dielectric resonators used in frequency control and selection. Published as Part 1 of the IEC 61994 series (second edition, 2007), this document codifies the state-of-the-art terminology intended for use across IEC TC 49 standards and related documents. It includes clear definitions, explanatory notes and figures (resonator configurations, equivalent circuits and frequency characteristics) to improve consistency in specifications, testing and product documentation.
Key topics
- Core definitions for resonator parameters: adjustment tolerance, ageing tolerance, drive level dependency, clamped/free capacitance, anti-resonance and resonance frequencies.
- Electrical models: equivalent circuit for one-port piezoelectric resonators (motional L, C, R and shunt C0) and related impedance/admittance concepts.
- Performance metrics: capacitance ratio, figure of merit, external quality factor, fractional pulling range and fractional load resonance offset.
- Device types and structures: crystal resonators, dielectric resonators (TE mode, coaxial, coplanar), SAW resonators and interdigital transducer (IDT) terminology.
- Material and coupling terms: electromechanical coupling factor and dielectric material definitions.
- Illustrative figures: configurations of dielectric resonators, equivalent circuits, SAW resonator layouts to aid interpretation.
Practical applications
- Ensures consistent use of terminology in product datasheets, test reports and procurement specifications for frequency control components (crystal units, SAW devices, dielectric resonators).
- Supports design and verification tasks in RF, microwave and timing applications by clarifying parameters engineers use for modeling, simulation and test.
- Aids test laboratories and quality assurance teams in interpreting measurement conditions and acceptance criteria.
- Useful for standards writers and regulatory documentation to harmonize language across IEC TC 49 deliverables.
Who should use this standard
- RF and microwave designers, oscillator and filter engineers
- Component manufacturers and test laboratories (crystal, SAW, dielectric resonator producers)
- Procurement, compliance and technical documentation teams
- Standards developers working on frequency control and selection technologies
Related standards
- Other parts of IEC 61994 series: Part 2 (filters), Part 3 (oscillators), Part 4-x (materials for crystal, ceramics, dielectric and SAW devices)
- Normative references cited: IEC 60050(561), IEC 60122-1, IEC 60642, IEC 61019-1, IEC 61338-1
By adopting IEC TS 61994-1:2007, organizations improve clarity and interoperability when specifying or testing piezoelectric and dielectric resonators used for frequency control.