Recently, we reported evidence for a novel mechanism of peripheral sensory coding based on oscillatory synchrony. Spontaneously oscillating electroreceptors in weakly electric fish (Mormyridae) respond to electrosensory stimuli with a phase reset that results in transient synchrony across the receptor population (Baker et al., 2015). Here, we asked whether the central electrosensory system actually detects the occurrence of synchronous oscillations among receptors. We found that electrosensory stimulation elicited evoked potentials in the midbrain exterolateral nucleus at a short latency following receptor synchronization. Frequency tuning in the midbrain resembled peripheral frequency tuning, which matches the intrinsic oscillationfrequencies of the receptors. These frequencies are lower than those in individual conspecific signals, and instead match those found in collective signals produced by groups of conspecifics. Our results provide further support for a novel mechanism for sensory coding based on the detection of oscillatory synchrony among peripheral receptors.
Contributors:Nguyen Hoang Mai, Tran van Dung
Hydropower Plants; Speed Control System; Magnetic Excitation; Power Grid; Gas Turbine; Power Plant; Damping; Low FrequencyOscillation; Linear Observer.
We further develop recently proposed new approach to description of the relativistic neutrino flavour νLe↔νLμ
, spin νLe↔νRe
and spin-flavour νLe↔νRμ
oscillations in a constant magnetic field that is based on the use of the exact neutrino stationary states in the magnetic field. The neutrino flavour, spin and spin-flavour oscillations probabilities are calculated. In general, the obtained expressions for the neutrino oscillations probabilities exhibit new inherent features in the oscillation patters that are missing when the customary approach (based on the use of the neutrino helicity states) is used. It is shown, in particular, that in the presence of the transversal magnetic field for a given choice of parameters (the energy and magnetic moments of neutrinos and strength of the magnetic field) the amplitude of the flavour oscillations at the vacuum frequency is modulated by the magnetic field frequency.
A new low-cost test approach is proposed for testing embedded RF passive filters (ERPFs) by one-port measurement. By this method, ERPFs testing is possible without a vector network analyzer. This method also enables testing of ERPFs without external test stimulus. In the proposed test approach, a shift in the oscillationfrequency of the test-setup is used to detect faults in the filters, but this test approach does not require reconfiguration or conversion of filters into an oscillator as it is done in conventional oscillation-based methods. The core principle of the method is to include an ERPF through a one-port substrate surface probe into an external RF oscillator circuitry, located on the probe card. Such one-port probing causes a change in the oscillationfrequency of the oscillator because of the loading from the RF filter, thus enabling low-cost testing of RF filters.
Contributors:Lörch, N, Nigg, SE, Nunnenkamp, Andreas, Tiwari, RP, Bruder, C
Classically, the tendency towards spontaneous synchronization is strongest if the natural frequencies of the self-oscillators are as close as possible. We show that this wisdom fails in the deep quantum regime, where the uncertainty of amplitude narrows down to the level of single quanta. Under these circumstances identical self-oscillators cannot synchronize and detuning their frequencies can actually help synchronization. The effect can be understood in a simple picture: Interaction requires an exchange of energy. In the quantum regime, the possible quanta of energy are discrete. If the extractable energy of one oscillator does not exactly match the amount the second oscillator may absorb, interaction, and thereby synchronization, is blocked. We demonstrate this effect, which we coin quantum synchronization blockade, in the minimal example of two Kerr-type self-oscillators and predict consequences for small oscillator networks, where synchronization between blocked oscillators can be mediated via a detuned oscillator. We also propose concrete implementations with superconducting circuits and trapped ions. This paves the way for investigations of new quantum synchronization phenomena in oscillator networks both theoretically and experimentally.
Contributors:Gianluca Cornetta, David J. Santos
This paper describes a 2.4 GHz passive switch mixer
and a 5/2.5 GHz voltage-controlled negative Gm oscillator (VCO)
with an inversion-mode MOS varactor. Both circuits are implemented
using a 1P8M 0.13 μm process. The switch mixer has an input
referred 1 dB compression point of -3.89 dBm and a conversion
gain of -0.96 dB when the local oscillator power is +2.5 dBm.
The VCO consumes only 1.75 mW, while drawing 1.45 mA from a
1.2 V supply voltage. In order to reduce the passives size, the VCO
natural oscillationfrequency is 5 GHz. A clocked CMOS divideby-
two circuit is used for frequency division and quadrature phase
generation. The VCO has a -109 dBc/Hz phase noise at 1 MHz
frequency offset and a 2.35-2.5 GHz tuning range (after the frequency
division), thus complying with ZigBee requirements.
Contributors:Augustin, Moritz, Ladenbauer, Josef, Obermayer, Klaus