Related Experiment Video
Updated: Jul 7, 2026
09:10
Fabrication and Testing of Microfluidic Optomechanical Oscillators
Published on: May 29, 2014
Extremely low phase noise UHF oscillators utilizing high-overtone, bulk-acoustic resonators
M M Driscoll1, R A Jelen, N Matthews
1Westinghouse Electric Corp., Baltimore, MD.
Summary
High-overtone, bulk acoustic resonators (HBAR) achieve 80,000 Q-factor at 640 MHz. These HBARs enable ultra-low phase noise oscillators with state-of-the-art frequency stability.
Area of Science:
- Electrical Engineering
- Materials Science
- Physics
Background:
- High-overtone, bulk acoustic resonators (HBAR) are critical components in advanced electronic systems.
- Achieving high Q-factor and stable frequency control remains a key challenge.
Purpose of the Study:
- To design and characterize HBARs for high-performance frequency control.
- To integrate these HBARs into low phase noise oscillators and evaluate their stability.
Main Methods:
- Design and fabrication of HBARs with specific performance targets.
- Development of oscillator sustaining stage circuitry with low-noise components.
- Measurement of oscillator output signal flicker-of-frequency noise and phase noise floor.
Main Results:
- HBARs exhibited 9-dB insertion loss and loaded Q of 80,000 at 640 MHz.
- Oscillators demonstrated state-of-the-art short-term frequency stability.
- Achieved a white phase noise floor of -175 dBc/Hz at 16-dBm resonator drive.
Conclusions:
- The designed HBARs are suitable for ovenized frequency-control elements.
- The oscillator circuitry effectively suppresses HBAR adjacent resonances and contributes minimally to noise.
- The study achieved excellent frequency stability and low phase noise performance.
Related Concept Videos
01:17Design Example: Underdamped Parallel RLC Circuit
Consider designing an oscillator circuit, a crucial component in various electronic devices and systems. The objective is to create an oscillator circuit with specific characteristics: a damped natural frequency of 4 kHz and a damping factor of 4 radians per second. To accomplish this, a parallel RLC circuit is employed, known for its ability to sustain oscillations at a resonant frequency. In this case, the damping factor is pivotal in achieving the desired performance.
Starting with a fixed...
Starting with a fixed...
01:19Concept of Resonance and its Characteristics
If a driven oscillator needs to resonate at a specific frequency, then very light damping is required. An example of light damping includes playing piano strings and many other musical instruments. Conversely, to achieve small-amplitude oscillations as in a car's suspension system, heavy damping is required. Heavy damping reduces the amplitude, but the tradeoff is that the system responds at more frequencies. Speed bumps and gravel roads prove that even a car's suspension system is not immune...
01:30Oscillations In An LC Circuit
An idealized LC circuit of zero resistance can oscillate without any source of emf by shifting the energy stored in the circuit between the electric and magnetic fields. In such an LC circuit, if the capacitor contains a charge q before the switch is closed, then all the energy of the circuit is initially stored in the electric field of the capacitor. This energy is given by
01:24Characteristics of Series Resonant Circuit
Series resonance occurs in a circuit containing inductive (L), capacitive (C), and resistive (R) elements connected sequentially. At the resonance frequency, the inductive and capacitive reactances are equal in magnitude but opposite in sign, effectively canceling each other. This causes the circuit's impedance is minimal, primarily determined by the resistance R. The resonant frequency of an RLC circuit is defined as:
01:14Sound Waves: Resonance
Resonance is produced depending on the boundary conditions imposed on a wave. Resonance can be produced in a string under tension with symmetrical boundary conditions (i.e., has a node at each end). A node is defined as a fixed point where the string does not move. The symmetrical boundary conditions result in some frequencies resonating and producing standing waves, while other frequencies interfere destructively. Sound waves can resonate in a hollow tube, and the frequencies of the sound...
01:23Parallel Resonance
The parallel RLC circuit is an arrangement where the resistor (R), inductor (L), and capacitor (C) are all connected to the same nodes and, as a result, share the same voltage across them. The parallel RLC circuit is analyzed in terms of admittance (Y), which reflects the ease with which current can flow. The admittance is given by: