8,399 research outputs found
An Integrated Subharmonic Coupled-Oscillator Scheme for a 60-GHz Phased-Array Transmitter
This paper describes the design of an integrated coupled-oscillator array in SiGe for millimeter-wave applications. The design focuses on a scalable radio architecture where multiple dies are tiled to form larger arrays. A 2 × 2 oscillator array for a 60-GHz transmitter is fabricated with integrated power amplifiers and on-chip antennas. To lock between multiple dies, an injection-locking scheme appropriate for wire-bond interconnects is described. The 2 × 2 array demonstrates a 200–MHz locking range and 1 × 4 array formed by two adjacent chips has a 60-MHz locking range. The phase noise of the coupled oscillators is below 100 dBc/Hz at a 1-MHz offset when locked to an external reference. To the best of the authors’ knowledge, this is the highest frequency demonstration of coupled oscillators fabricated in a conventional silicon integrated-circuit process
Injection locking of an electro-optomechanical device
The techniques of cavity optomechanics have enabled significant achievements
in precision sensing, including the detection of gravitational waves and the
cooling of mechanical systems to their quantum ground state. Recently, the
inherent non-linearity in the optomechanical interaction has been harnessed to
explore synchronization effects, including the spontaneous locking of an
oscillator to a reference injection signal delivered via the optical field.
Here, we present the first demonstration of a radiation-pressure driven
optomechanical system locking to an inertial drive, with actuation provided by
an integrated electrical interface. We use the injection signal to suppress
drift in the optomechanical oscillation frequency, strongly reducing phase
noise by over 55 dBc/Hz at 2 Hz offset. We further employ the injection tone to
tune the oscillation frequency by more than 2 million times its narrowed
linewidth. In addition, we uncover previously unreported synchronization
dynamics, enabled by the independence of the inertial drive from the optical
drive field. Finally, we show that our approach may enable control of the
optomechanical gain competition between different mechanical modes of a single
resonator. The electrical interface allows enhanced scalability for future
applications involving arrays of injection-locked precision sensors.Comment: Main text: 10 pages, 7 figures. Supplementary Information: 5 pages, 4
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Novel Sub-Harmonic Injection-Locked Balanced Oscillator
A novel sub-harmonic injection-locked balanced oscillator is proposed. The circuit provides two outputs with a 180° ° phase difference by employing a transmission line section for impedance transformation to meet the oscillation conditions. A coupling network is connected at the mid-point of the transmission line to inject the sub-harmonic frequency. This eliminates the need for a circulator or balun. The circuit is small and consumes low DC power. Under the locking state, the circuit provides double the injection frequency and also the phase noise of the two outputs is substantially improved
Injection locking of optomechanical oscillators via acoustic waves
Injection locking is a powerful technique for synchronization of oscillator
networks and controlling the phase and frequency of individual oscillators
using similar or other types of oscillators. Here, we present the first
demonstration of injection locking of a radiation-pressure driven
optomechanical oscillator (OMO) via acoustic waves. As opposed to previously
reported techniques (based on pump modulation or direct application of a
modulated electrostatic force), injection locking of OMO via acoustic waves
does not require optical power modulation or physical contact with the OMO and
it can easily be implemented on various platforms. Using this approach we have
locked the phase and frequency of two distinct modes of a microtoroidal silica
OMO to a piezoelectric transducer (PZT). We have characterized the behavior of
the injection locked OMO with three acoustic excitation configurations and
showed that even without proper acoustic impedance matching the OMO can be
locked to the PZT and tuned over 17 kHz with only -30 dBm of RF power fed to
the PZT. The high efficiency, simplicity and scalability of the proposed
approach paves the road toward a new class of photonic systems that rely on
synchronization of several OMOs to a single or multiple RF oscillators with
applications in optical communication, metrology and sensing. Beyond its
practical applications, injection locking via acoustic waves can be used in
fundamental studies in quantum optomechanics where thermal and optical
isolation of the OMO are critical
Observation of injection locking in an optomechanical rf oscillator
Injection locking of a radiation-pressure optomechanical oscillator is demonstrated through external modulation of the optical pump power near the optomechanical oscillation frequency. It is shown that the frequency and phase of a microtoroidal optomechanical oscillator can be locked to those of an electronic oscillator (or any other signal) that can modulate the optical input power and whose frequency is within the lock range
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