QAM Receiver I. General Description of Complete Receiver Block Diagram and Details of the Symbol Clock Recovery and Other Front-End Subsytems

This paper describes an achieved result in designing of the four-receiver microwave hyperspectrometer based on zero measurement method and the multi-receiver concept of realization. The block diagrams of the microwave front-end with operating frequency band from 18 to 26.5 GHz, the radiometric receiver, and the frequency transmission module are shown. The technical implementation of every described blocks of the microwave hyperspectrometer are described. Presented technical implementation includes a list of modern components are used to designing of laboratory model of hyperspectrometer. The detailed block diagram of the microwave front-end is presented. Description of main technical characteristics of parts of the microwave front-end is also presented. The analysis of a technical characteristics influence to measurement errors is shown. The mathematical model of a measurement error calculation in hyperspectral modeis described. The influence of the active reference noise generator temperature accuracy, the directional coupler insertion loss and the passive reference noise generator temperature accuracy to a measurement errors are described. A numerical experimental results of designed mathematical model are presented. The dependence of the minimum value of measurement errors form the temperature of passive noise generator is presented.

Download Full-text

Simulation of the effects of load on hydraulic servo actuators

SIMULATION ◽

10.1177/003754976901200309 ◽

1969 ◽

Vol 12 (3) ◽

pp. 145-151 ◽

Cited By ~ 1

Author(s):

Myron Glickman

Keyword(s):

Control System ◽

Closed Loop ◽

Block Diagram ◽

System Simulation ◽

Loop System ◽

General Description ◽

Control Loop ◽

Closed Loop System ◽

Servo Actuator ◽

Hydraulic Servo

Control system analysts are frequently called upon to include a hydraulic servo actuator as part of the loop in a complex closed-loop system simulation. This article presents a general description of several common types of hydraulic servo actuators and several methods for inclusion of the effects of load on the simulation of the actuator in the control loop. These methods are pre sented in block diagram form and are suitable for inclu sion in a larger simulation loop. The block diagrams themselves may be somewhat condensed and modified before inclusion in a larger simulation, but are presented here with all the details shown explicitly for clarity.

Download Full-text

An Image Reconstruction System Applied to High Voltage Microscopy

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100115080 ◽

1975 ◽

Vol 33 ◽

pp. 292-293

Author(s):

D. E. Johnson

Keyword(s):

High Voltage ◽

Prior Information ◽

Block Diagram ◽

Three Dimensional ◽

Real Space ◽

Two Dimensional ◽

Efficient Manner ◽

Fourier Methods ◽

Tilt Series ◽

Methods Of Reconstruction

Increased specimen penetration; the principle advantage of high voltage microscopy, is accompanied by an increased need to utilize information on three dimensional specimen structure available in the form of two dimensional projections (i.e. micrographs). We are engaged in a program to develop methods which allow the maximum use of information contained in a through tilt series of micrographs to determine three dimensional speciman structure.In general, we are dealing with structures lacking in symmetry and with projections available from only a limited span of angles (±60°). For these reasons, we must make maximum use of any prior information available about the specimen. To do this in the most efficient manner, we have concentrated on iterative, real space methods rather than Fourier methods of reconstruction. The particular iterative algorithm we have developed is given in detail in ref. 3. A block diagram of the complete reconstruction system is shown in fig. 1.

Download Full-text

On-line alignment and astigmatism correction using a TV and personal computer

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100146850 ◽

1993 ◽

Vol 51 ◽

pp. 202-203

Author(s):

F. Hosokawa ◽

Y. Kondo ◽

T. Honda ◽

Y. Ishida ◽

M. Kersker

Keyword(s):

High Resolution ◽

Personal Computer ◽

Block Diagram ◽

Incident Beam ◽

Ccd Camera ◽

Alignment Procedure ◽

Astigmatism Correction ◽

Transmission Electron ◽

Alignment System ◽

On Line

High-resolution transmission electron microscopy must attain utmost accuracy in the alignment of incident beam direction and in astigmatism correction, and that, in the shortest possible time. As a method to eliminate this troublesome work, an automatic alignment system using the Slow-Scan CCD camera has been introduced recently. In this method, diffractograms of amorphous images are calculated and analyzed to detect misalignment and astigmatism automatically. In the present study, we also examined diffractogram analysis using a personal computer and digitized TV images, and found that TV images provided enough quality for the on-line alignment procedure of high-resolution work in TEM. Fig. 1 shows a block diagram of our system. The averaged image is digitized by a TV board and is transported to a computer memory, then a diffractogram is calculated using an FFT board, and the feedback parameters which are determined by diffractogram analysis are sent to the microscope(JEM- 2010) through the RS232C interface. The on-line correction system has the following three modes.

Download Full-text