666 results about "Return-to-zero" patented technology

An improved Rail Adaptor System / Rail Accessory System (RAS) which attaches to a firearm. The rail is top opening, modular, and free floats the barrel. Provided is a rigid, lightweight, strong platform for mounting firearm accessories. Heat transmission from the barrel assembly to the user is limited. The user is also protected from ventilated gases originating from the operating system. A quick detachable top rail section is provided so that that gas system may be easily accessed. This removable top section of the rail is what makes this device unique because the RAS may be installed without removing the barrel, gas system, front sight base, flash hider or the barrel nut. The herein described RAS is adaptable to a wide variety of firearms with the use of conversion parts. The top rail “returns to zero” on reinstallation allowing the remounting of various optics and electronic gun sites without the need to realign them.

A method and apparatus for controlling a bias voltage of a Mach-Zehnder modulator (MZM) use a digital pilot signal and a digital correlation technique to produce a feedback signal for adjusting the bias voltage to the quadrature bias point. Embodiments of the invention include apparatuses performing a non-return-to-zero (NRZ), return-to-zero (RZ), or carrier suppressed RZ (CSRZ) high-speed optical modulation.

A “return-to-zero” (RZ) current switching DAC includes an analog output node for which a “zero” potential has been defined. The outputs of a plurality of current sources are selectively directed to respective intermediate nodes in response to respective control signals, which are varied in synchronization with a clock signal CK. A plurality of RZ circuits are connected between respective intermediate nodes and the analog output node. In a preferred embodiment, each RZ circuit directs the current applied to a respective intermediate node to ground or to the analog output node in synchronization with CK. An output network pulls the analog output node to the “zero” potential when currents applied to the intermediate nodes are directed to ground.

Invention resides in a switching amplifier having a quaternary input control signal that provides quaternary levels (1, 0H, -1, and 0L) which is coupled to an H-bridge amplifier to provide error cancellation in switching amplifier output signal. The quaternary control signal alternates from a zero state at a high level ("0H") to a zero state at a low level ("0L") between each non-zero state (+1 or -1). In a preferred embodiment, a three-level sigma-delta modulator is provided for greater operational efficiency for ease of detecting zero states and minimizing power. The three-level sigma-delta modulator receives and converts an amplifier input signal into a ternary output signal that is then coupled to a ternary-to-quaternary converter to generate the quaternary control signal to provide as input to the H-bridge.

Optical transmitter / receivers for use in a DWDM systems are provided. Transmission of data signals in a quadrature-return-to-zero (QRZ) format achieves a data transmission rate equal to eight times a base data rate, i.e., 80 Gbps over a 100 GHz channel if the base data rate is 10 Gbps, with high non-linear performance by setting the polarization state of the data bands such that non-linear effects induced by PMD are reduced. Additionally, a transmitter achieves a transmission data rate equal to 16 times the base data rate by sharpening the QRZ pulses and interleaving pulse-sharpened QRZ data signals in the time domain, further doubling the data rate. Using counterpropagation in the transmitter, carrier signals and data signals traverse the same length of fiber, reducing fringing effects in the transmitter. Related techniques enhance reception and detection of data at high data rates. A local pulse-sharpened carrier is mixed with a QRZ data signal at a detector reducing amplification noise by a factor of two. A bi-directional Erbium-doped fiber amplifier is used to amplify a carrier signal while limiting fringing effects by sending carrier and data signals along equal optical path lengths. Non-linear effects are reduced by transmitting carrier signals in an othogonal polarization state with respect to data signals, and PMD phase noise effects are compensated for in both single channel and DWDM multi-channel systems by using delay management.