摘要:
Methods and apparatus for implementing stable self-starting and self-sustaining high-speed electrical nonlinear pulse (e.g., soliton, cnoidal wave, or quasi-soliton) oscillators. Chip-scale nonlinear pulse oscillator devices may be fabricated using III-V semiconductor materials (e.g., GaAs) to attain soliton pulse widths on the order of a few picoseconds or less (e.g., 1 to 2 picoseconds, corresponding to frequencies of approximately 300 GHz or greater). In one example, a nonlinear pulse oscillator is implemented as a closed loop structure that comprises a nonlinear transmission line and a distributed nonlinear amplifier arrangement configured to provide a self-adjusting gain as a function of an average voltage of the oscillator signal. In another example, a nonlinear oscillator employing a lumped nonlinear amplifier and a nonlinear transmission line in a closed loop arrangement may be used in combination with a two-port nonlinear transmission line that provides additional pulse compression for pulses circulating in the oscillator.
摘要:
Methods and apparatus for implementing stable self-starting and self-sustaining electrical nonlinear pulse (e.g., soliton, cnoidal wave, or quasi-soliton) oscillators. In one example, a nonlinear pulse oscillator is implemented as a closed loop structure that comprises a nonlinear transmission line, an improved high-pass filter, and a nonlinear amplifier configured to provide a self-adjusting gain as a function of an average voltage of the oscillator signal, to provide a pulse waveform having a desired target amplitude. In one implementation, the nonlinear amplifier and high pass filter functions are integrated in a two stage nonlinear amplifier/filter apparatus employing complimentary NMOS and PMOS amplification components and associated filtering and feedback circuitry configured to essentially implement an electric circuit analog of a saturable absorber via an adaptive bias control technique.
摘要:
Methods and apparatus for implementing stable self-starting and self-sustaining high-speed electrical nonlinear pulse (e.g., soliton, cnoidal wave, or quasi-soliton) oscillators. Chip-scale nonlinear pulse oscillator devices may be fabricated using III-V semiconductor materials (e.g., GaAs) to attain soliton pulse widths on the order of a few picoseconds or less (e.g., 1 to 2 picoseconds, corresponding to frequencies of approximately 300 GHz or greater). In one example, a nonlinear pulse oscillator is implemented as a closed loop structure that comprises a nonlinear transmission line and a distributed nonlinear amplifier arrangement configured to provide a self-adjusting gain as a function of an average voltage of the oscillator signal. In another example, a nonlinear oscillator employing a lumped nonlinear amplifier and a nonlinear transmission line in a closed loop arrangement may be used in combination with a two-port nonlinear transmission line that provides additional pulse compression for pulses circulating in the oscillator.
摘要:
Methods and apparatus for implementing stable self-starting and self-sustaining electrical nonlinear pulse (e.g., soliton, cnoidal wave, or quasi-soliton) oscillators. In one example, a nonlinear pulse oscillator is implemented as a closed loop structure that comprises a nonlinear transmission line, an improved high-pass filter, and a nonlinear amplifier configured to provide a self-adjusting gain as a function of an average voltage of the oscillator signal, to provide a pulse waveform having a desired target amplitude. In one implementation, the nonlinear amplifier and high pass filter functions are integrated in a two stage nonlinear amplifier/filter apparatus employing complimentary NMOS and PMOS amplification components and associated filtering and feedback circuitry configured to essentially implement an electric circuit analog of a saturable absorber via an adaptive bias control technique.
摘要:
Methods and apparatus utilizing the quantum inductance of one-dimensional (ID) nanoscale structures (e.g., nanowires, carbon nanotubes). In one exemplary circuit implementation, all elements of a high-frequency circuit path are constituted by nanoscale structures without significant intervening structures (e.g., metal contacts) that would introduce undesirable resistance in the high-frequency circuit path. In this manner, the deleterious effects of contact resistance (e.g., metal-to-nanostructure interfaces) on the quality factor associated with the quantum inductance, and ultimately operation of the circuit, may be significantly reduced or avoided.
摘要:
The Rabi frequency of oscillation of the nuclear magnetization vector of a sample in an NMR system may be controlled by modifying only the duty cycle of RF pulses delivered to the sample, without modifying the amplitude of the RF pulses, until the energy delivered at the Larmor frequency is adjusted to a desired amount. An impedance matching network between an NMR transceiver and an NMR coil may perform both power matching and noise matching simultaneously. During a transmission mode, the impedance matching network is connected to a transmitter portion of the transceiver, and the impedance of the coil is matched to the driver resistance. During a receiver mode, the impedance matching network is disconnected from the transmitter portion so that the impedance matching network remains connected only to the receiver portion, and signal-to-noise ratio in received NMR signals is maximized.
摘要:
Methods and apparatus for manipulation, detection, imaging, characterization, sorting and/or assembly of biological or other materials, involving an integration of CMOS or other semiconductor-based technology and microfluidics. In one implementation, various components relating to the generation of electric and/or magnetic fields are implemented on an IC chip that is fabricated using standard protocols. The generated electric and/or magnetic fields are used to manipulate and/or detect one or more dielectric and/or magnetic particles and distinguish different types of particles. A microfluidic system is fabricated either directly on top of the IC chip, or as a separate entity that is then appropriately bonded to the IC chip, to facilitate the introduction and removal of cells in a biocompatible environment, or other particles/objects of interest suspended in a fluid. The patterned electric and/or magnetic fields generated by the IC chip can trap and move biological cells or other objects inside the microfluidic system. Electric and/or magnetic field generating components also may be controlled using signals of various frequencies so as to detect one or more cells, particles or objects of interest, and even the type of particle or object of interest, by measuring resonance characteristics associated with interactions between samples and one or more of the field-generating devices. Such systems may be employed in a variety of biological and medical related applications, including cell sorting and tissue assembly.
摘要:
Methods and apparatus involving semiconductor devices based on coplanar striplines (CPS). In one example, high-speed microelectronic devices based on coplanar stripline implementations support differential signals in a range of approximately from 1 Gigahertz to at least 60 Gigahertz. In one aspect, CPS-based devices incorporate various features that dramatically increase the quality factor Q of the resulting device. In another aspect, an enhancement of the quality factor Q is achieved while at the same time reducing the phase velocity of one or more waves propagating in the device, thereby also facilitating the fabrication of relatively smaller devices. In yet another aspect, a tapered coplanar stripline configuration results in position-dependent line parameters, which may be exploited to achieve significantly high-Q devices. Examples of CPS-based devices incorporating such features include impedance matching devices, devices for power combining and division, delays, resonators, oscillators, filters, amplifiers, mixers and the like, including CMOS-based implementations of such devices.
摘要:
Methods and apparatus for implementing standing wave oscillators (SWOS) using coplanar striplines (CPS). One example is given by a quarter-wavelength (λ/4) coplanar stripline standing wave oscillator (SWO), while another implementation utilizes a closed-loop coplanar stripline configuration. In various aspects, SWOs are configured to optimize sinusoidal performance at high frequencies with low power dissipation by incorporating various features that dramatically increase the quality factor Q of the oscillator. In particular, in one aspect, an amplitude-dependent tailored distributed amplification scheme is employed as a mode control technique using multiple amplifiers having different gains along the length of the coplanar stripline. In another aspect, a coplanar stripline configured such that its resistance per unit length R and conductance per unit length G are discreet or continuous functions of position along the coplanar stripline is employed to reduce SWO losses. In another aspect, an enhancement of the quality factor Q is achieved while at the same time reducing the phase velocity of waves propagating in the SWO, thereby also facilitating the fabrication of relatively smaller devices. In yet another aspect, SWOs are configured with frequency adjustability that is again optimized to reduce power dissipation while facilitating significant adjustments of oscillator frequency.
摘要:
Digital background calibration in a pipelined ADC is performed by extracting a capacitor mismatch value Δ that represents a mismatch between a sampling capacitor C1 and a feedback capacitor C2 in the pipelined ADC, and using Δ to correct the capacitor mismatch error. Δ is extracted by performing commutated feedback capacitor switching (CFCS) in a background correlation loop. The error caused by the capacitor mismatch is calibrated out by subtracting the error from a digital output Dout of the pipelined ADC. Convergence speed may be accelerated and convergence accuracy may be increased during digital background calibration of pipelined ADCs, by using a higher order LPF. A bandwidth switching scheme may be implemented by the LPF, i.e. a larger bandwidth may be utilized during calibration start-up to increase convergence speed during start-up and a smaller bandwidth may be utilized during steady state to increase convergence accuracy during steady state.