SAW Oscillator Circuit for Fast Resonator Startup
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Oscillators using surface acoustic wave (SAW) resonators exhibit an initial delay of approximately 20 to 30 microseconds to start oscillating, which is undesirable for rapid frequency stabilization in radiofrequency and data transmission systems.
Innovation Solution
A surface wave resonator driving circuit is designed with a Colpitts oscillator configuration, incorporating specific values of inductors and capacitors to rapidly resonate with the SAW resonator, allowing it to start oscillating within about 100 nanoseconds by using a parallel circuit of resistor R3 and inductor L3, which determines the initial oscillation frequency and maintains it during operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If a conventional oscillator circuit is used with a SAW resonator, then the circuit is simple to implement, but the oscillation startup time is long (20-30 microseconds)
Solution Approach 1:
The patent applies preliminary action by pre-configuring the driving circuit with specific inductor and capacitor values that are optimized to resonate at the SAW resonator's frequency from the moment power is applied. This pre-configuration allows the circuit to immediately drive the resonator into oscillation without requiring a warm-up period, reducing startup time from 20-30 microseconds to approximately 100 nanoseconds.
Solution Approach 2:
The patent changes the electrical parameters of the driving circuit by selecting specific values for inductors (L1, L2, L3) and capacitors (C1, C2, C3) that create a resonant condition matching the SAW resonator's operating frequency. This parameter optimization ensures maximum energy transfer and rapid oscillation buildup, solving the contradiction between simple circuit implementation and fast startup.
2Speed
If the SAW resonator is driven with high power to reduce startup time, then oscillation starts faster, but energy consumption increases
Solution Approach 1:
The patent employs periodic action through the natural resonant oscillation of the SAW resonator, which efficiently stores and releases energy in a cyclic manner. The driving circuit is designed to supply energy in sync with the resonator's natural frequency, ensuring that energy is added during each oscillation cycle rather than continuously. This resonant coupling allows rapid oscillation startup (100 nanoseconds) while minimizing overall energy consumption, as the system leverages the resonator's inherent energy storage capability.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The driving circuit enables the SAW resonator to initiate oscillations rapidly, overcoming mechanical inertia and stabilizing frequency within 50 nanoseconds, ensuring efficient operation in radiofrequency and data transmission systems.
Implementation Method 1
reactive means, i.e. inductor L3, having a value so as to resonate in combination with said static capacitor Co of the resonator at a predetermined frequency Fo
Implementation Method 2
Oscillators using Surface Acoustic Waves (SAW) are currently used in radiofrequency signal and data transmission systems
Implementation Method 3
Oscillators in which oscillation frequency is stabilized by quartzes or piezoelectric resonators are known
Data Source
Figure 1~3
Figure 4~5
AI summary
A driving circuit of a surface wave resonator (X1) is described; the resonator comprises a static capacitor (Co) and the driving circuit is adapted to supply a voltage (Vx) to the resonator. The driving circuit comprises reactive means (L3) adapted to resonate in combination with said static capacitor (Co) of the resonator at a predetermined frequency (Fo) in the initial driving period of the resonator at said voltage; the driving circuit comprises passive means (R3) adapted to determine oscillations at said predetermined frequency (Fo).