Pulse Pattern Generator Research Articles

Three Level IGBT Inverters for Industrial Drives and Traction Applications

The advantages of application of IGBTs in PWM-inverters in industrial motor drives with 3-phase voltage of 400 V and medium power range are well known. To extend the application to industrial motor drives with 3-phase voltage of 690 V and to local traffic with de-line voltage of 600/750 V three level IGBT inverters present a good solution. In this paper some details regarding the realization of the power circuit and the pulse pattern generator with space vector modulation are explained. Three level IGBT inverters are now successfully applied in drives for modern low floor trams. The advantageous performance of these inverters will be illustrated.

Surface Acoustic Wave Multiple Phase Shift Keying Modulator-Demodulator Circuits

Multiple phase shift keying technology is effectively used in various communication systems because of its high-capacity data transmission capability along a restricted passband. This-paper proposes a high-performance offset quadri-pulse shift keying modulator and demodulator with a new simple circuit configuration employing surface acoustic wave (SAW) devices. We propose two types of modulators (modulation and pulse pattern generation method) and a demodulator with a differential-operation SAW device. A fundamental experiment verified the feasibility of the circuits.

Design and performance of clock recovery GaAs ICs for high-speed optical communication systems

Design and performance of clock-recovery GaAs ICs are presented. Four kinds of ICs were developed: a limiting amplifier, a tuning amplifier, a rectifier, and a differentiator. The cascaded limiting amplifier together with a tuning amplifier achieved a 58-dB gain and a 10-degree phase deviation with 20-dB input dynamic range at 10 GHz. A clock-recovery circuit successfully extracts a low-jitter 10-GHz clock signal of 1-dBm constant power from 10-Gb/s NRZ pseudorandom bit streams using a pulse pattern generator. >

A HDTV Sync Pulse and Test Pattern Generator for 1050/59.94/2:1 and 525/59.94/1:1

At the time HDTV is the most discussed issue in the professional world of television. From this discussion it is becoming more and more obvious that in the United States will be a strong demand for a compatible standard. — This paper discribes the digital signal generation of a combined HDTV Sync Pulse and Test Pattern Generator for, besides other standards. 1050/59.94/2:1 and 525/59.94/1:1. — The principle of generating complex test patterns, especially circular test patterns is discussed. This principle is implemented in the Test Pattern Generator. Thus, one important feature is a zoneplate test pattern with variable motion. In addition there are other standard test patterns like colour bars, sawtooth, grid etc. — A second part of the paper describes the Sync Pulse Generator portion. This portion, which can be externally synchronised, delivers besides the tri- level sync, horizontal drive, vertical drive, field identification, composite blanking and a two- level sync. — In genlock operation it is possible to shift the horizontal output sync with respect to the input sync by +/ — 4.6 μs. — All user set-ups including the change-over between the two standards can be achieved by a menu driven control system. — The TEST H 1000 is housed in a 19 inch rack frame, which is only one rack unit high.

Field Orientated Control with Subordinated Pulse Pattern Generation of PWM Converter Fed Induction Machines

A field orientated control strategy with subordinated pulse pattern generation, for induction machines fed by PWM converters with low switching frequencies, is presented. The control circuit supplies the fundamental waveforms of the stator currents, while the current harmonics are optimized by the voltage control scheme. The whole control system is digitally implemented, by means of a microcomputer system.After describing the function of the PWM-modulator the control concept is shown. The signal processing strategy, which includes the applied machine model, the coordinate transformations and the embedding of the modulator is explained. The acquisition of the quantities to be measured, speed and stator currents, is depicted in detail.The controller functions are mainly performed by software. After classifying these tasks according to their priority the software section is described, which comprises the control and pulse pattern generation algorithms.By means of measurements on a test drive the principles of operation of the presented concept, the independent execution of closed loop control and pulse pattern generation is documented.

Power penalty due to decision-time jitter in receivers using avalanche photodiodes

Power penalties on receiver sensitivity due to the presence of timing jitter are derived for receivers incorporated with PIN detectors and with avalanche photodiodes. It is shown that the presence of timing jitter will lower the optical gain of the avalanche photodiodes and will reduce the improvement in receiver sensitivity of using avalanche photodiodes over PIN detectors. Using computer simulation on results of transmission experiments it is shown that the receiver sensitivity can be degraded by several decibels owing to the presence of timing jitter in the Anritsu pulse pattern generator and/or error detector.

A Programmed Digital IC Pulse Generator for Transient NMR Spectrometry

A pulse pattern generator for NMR spectrometry using SGS micrologic IC's for the logic and counters is described. Time intervals between pulses, gate times controlling the number of pulses in a sequence, and delay times controlling the sequence repetition rates are all digitized. Auxiliary pulse outputs to use as suppression pulses, for controlling delay lines, and for gated signal averaging devices are provided. The pulse sequences are those most commonly used in relaxation times measurements, including T1ρ. The generation of further sequences and the possibilities of using the flexible logic of this apparatus for extending its use are discussed.

A high-speed wide-band X-band FM deviator with a Gunn-effect diode

An X-band FM deviator with a Gunn diode has been developed which can be tuned from 9.8 to 10.5 GHz by a 2.7 volt change in bias voltage, with an output power of greater than +10.5 dBm over the band flat to within 2 dB. High-speed operations employing a 224 Mbit/s (megabits per second) pulse pattern generator have shown that the deviator is capable of following the input signal.

Pulse Pattern Generator for Transient NMR Experiments

A pulse pattern generator for transient NMR experiments has been built using commercially available solid state circuit modules. The generator provides stable pulse widths and delays from a few microseconds to several seconds. By replacing a single blank module the logic can be changed from a Carr-Purcell T2 sequence to a T1 sequence of pulse pairs with systematically increasing delay between pulses. The 90 and 180° pulse widths are accurately preserved in the change over. A variety of gating pulses are available to synchronize oscilloscopes or to activate circuits for suppressing the ring following a transmitted pulse.