WEB ASSISTED DESIGN OF COMMUNICATION

CIRCUITS AND SYSTEMS

Galia Marinova

Telecommunications Faculty, Technical University – Sofia-1000,

8, bul. Kliment Ohridski, Sofia, Bulgaria,

gim@tu-sofia.bg

Keywords: Online calculators, Web assisted design, Computer-aided design, Antenna, LED, SMPS, PSPICE, PCB

Abstract: Online calculators, generators, wizards and free design tools increased considerably the accessibility of

communication circuits and systems design. The paper presents a study on the online design tools and

defines design tasks that can be solved with their assistance. The concept of Local resources, assisted by

Web assistants in a Web portal, is considered. The Web assistants in the portal integrate Sets of connexions

and e-Content. The paper gives examples combining online tools with locally installed Computer-aided

design (CAD) tools for more effective communication circuits and systems design

1 INTRODUCTION

Nowadays we are witnessing a boom of specialized

web resources, online platforms, portals, programs,

calculators. Smaller or bigger centers make research,

characterization, categorization and development of

sets of connections to these web resources. One of

the biggest centers for connections with specialized

online resources is the MARTINDALE’S

Calculators Online Center (MARTINDALES) where

connections are built forward 24385 online

calculators, 4145 e-learning materials and lecture

courses and 1000 films, video and animation

products and simulations, created by more than 8620

authors from all over the world. The web

connections in the Center are categorized by areas,

covering a very wide specter, from agriculture and

archeology passing through mathematics and

engineering and ending by physics and chemistry.

Smaller specialized portals in the area of

communications exist, as for example, the portals

of the SPICE community (YOUSPICE, e-

CircuitCenter, etc. ), the portals for audio design,

which have built sets of tens to hundreds of

connections to useful resources in the Web. Besides

the disconnected online resources, online platforms

for solving complex research and design tasks in

communications became accessible during the last

years. The Free online platform for switch-mode

power supply (SMPS) design, on web address

www.PowerEsim.com and the SCA-Based Open

Source Software Defined Radio on web address

http://ossie.wireless.vt.edu/ are such examples. Both

are developed as result of serious scientific projects.

PowerEsim is the result of a research project in

Hong Kong, and SCA-Based Open Source Software

Defined Radio is the result from a project of the

National Research Foundation in USA. All

specialized online platforms and portals can be used

in education, but this is neither their main

application, nor the unique one. They make

accessible an environment for solving real tasks

from system design in communications with

elements of business analysis and decisions. Some

of these platforms integrate local resources with

online resources for solving design and test tasks.

The platforms as WeBench Designer of Texas

Instruments: for designing SMPS, LED, FPGA,

Sensors, which make available considerable free

resources, are between the most popular in this

category. We have experienced applying online

resources mainly in e-education and most

universities have e-Learning Centers or Distance

Learning Centers. In the present work the accent is

on the Useful resource on the web and the

development of Sets of connections in order to solve

Computer-aided design (CAD) tasks in the area as

communications. Thus acceleration of scientific

research can be achieved.

175

Marinova G.

WEB ASSISTED DESIGN OF COMMUNICATION CIRCUITS AND SYSTEMS.

DOI: 10.5220/0005415601750184

In Proceedings of the First International Conference on Telecommunications and Remote Sensing (ICTRS 2012), pages 175-184

ISBN: 978-989-8565-28-0

2 CONCEPT OF PORTAL WITH

WEB ASSISTANTS TO LOCAL

RESOURCES FOR CAD OF

COMMUNICATION CIRCUITS

AND SYSTEMS

A Multitool environment for Computer-Aided

Design in Communications was described in

(Marinova, 2010). The goal was to combine multiple

tools in order to design a communication system.

The set, of locally installed CAD tools in the

environment, is composed from the following

programs:

• MATLAB,

• ORCAD/Capture, ORCAD/Layout,

• PSpice A/D and Advanced analysis,

• WARP 6.2,

• ISE WEBPACK,

• II, QUARTUS

•

MMICAD,

• FilterCAD,

• PAC Designer,

• MICROWIND.

The integration of these tools for solving

different tasks is described in details in (Marinova,

2010). At a next step it becomes interesting to assist

these Local resources by a Set of Useful online

resources. This is realised through definition of a Set

of CAD tasks suitable for the Local resources. Then

a Portal is developed with Web assistants in order to

provide knowledge from the web helping the task

solution. The Web assistants are composed by a Set

of connections to the Useful web resources and e-

Content. The Useful net resources are determined

after a serious research in the web and selection of

online tools suitable for the Set of CAD task.

Additional tests and verifications of the online tools

are performed before admitting them as a Useful

resource. A characterization is made for their

application area. The Concept of the Web assistants

combined to Local resources, for CAD of

communication circuits and systems is presented on

Figure 1. The Portal with Web assistants for CAD of

communication circuits and systems is presented on

Fig

ure 2.

defined:

A set of CAD tasks is

• Antenna design;

• LED array, controller and driver design;

Switch-m

• ode power supplies (SMPS)

• PCB design price estimation.

design;

• Design with PSpice;

• PCB trace estimation;

Figure 1.

Figure 2.

3 SETS OF CONNECTIONS IN

THE WEB ASSISTANTS

The Set of connections for each Web assistant is

built after a serious research in the web for online

calculators, tools and materials, related to the

corresponding Set of CAD tasks. Each online tool is

tested and if the test result is satisfactory the web

address is added to the Set of connections. Each

online tool is accompanied by short characteristics,

describing its specific functions. Six Sets of

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176

connections are built in order to assist solving the

Set of CAD tasks described above:

Set of connections for Antenna design: 10

online calculators are considered for the design of 7

of the most popular types of antennas: LPDA, Yagi,

Moxon, Helix, Microstrip Patch, Delta loop and

Magnetic loop. The Set is presented in Table 1.

Set of connections for LED array, driver and

controller design: 5 online calculators and one free

downloadable program for LED array design,

Current limiting resistor calculation, LED driver

design and LED controller programming are

selected and presented in Table 2.

Set of connections for SMPS design: The free

online platform for SMPS design PowerEsim, as

well as WEBENCH POWER DESIGNER (TI) and a

portal for SMPS projects simulated with PSpice are

selected and presented in Table 3. The PowerEsim

platform was tested. Verification with PSpice was

performed for the design of a Full bridge DC-DC

converter and the results from the verification are

presented in (Marinova, July 2012). The content of

the portal SMPS was studied in details and an

application limitation coming from the paid PSpice

projects of SMPS was observed.

Set of connections for Design with Spice –

Three portals – eCircuitCenter, YOUSPICE and

SMPS are selected and considered and the set of

connections is presented in Table 4. The free

Circuits collections were tested with a local PSpice

A/D tool and several remarks and corrections were

reported for some of the projects in these portals.

The specific advantage of the portal YOUSPICE is

the mechanism for SPICE project exchange. New

point in the portal eCircuitCenter is the online

EXCEL based design calculations for the design of

certain circuits – audio amplifiers for example. The

PSpice projects of the portal SMPS are entirely paid

and even the electrical circuit of the SMPS is not

fully visible without registration.

Set of connections for PCB trace estimation –

6 online calculators are selected and a free

downloadable tool Saturn and their main

characteristics are presented in Table 5.

Set of connections for PCB design price

estimation – an online calculator and 2 tabular

online tools are selected and presented in Table 6.

The research covers until now 32 resources from

the Web which are selected, studied and added to the

Sets of connections to the Web assistants in the

Portal for computer-aided design of communication

circuits and systems. The research continues by

adding new Sets of connections with:

• Online calculators for resistors and

capacitors;

• Online matching network tools – Smith

Chart diagram tools;

• Online analogue/digital/crystal filters

design tools;

• Online 555 timer calculators;

• Online design tools for loudspeakers and

microphones (mono and stereo);

• Online SCA based open source software

defined radio - OSSIE.

4 ILLUSTRATIVE EXAMPLES

OF WEB ASSISTED

COMPUTER-AIDED DESIGN

In (Marinova, June 2012) there are some examples

given for web assisted computer aided design. Two

additional examples, design with WENENCH LED

DESIGNER and design with WARP 6.2. and LED

current limiting resistor calculator, are given further.

4.1 Design of LED array with 5x7

orange LEDs and a driver in

WEBENCH LED DESIGNER

Orange LEDs 35 (5х7), with forward voltage 2.9 V

and forward current of 0.35 mA, are chosen. The

power supply is 12 V. The LEDs chosen for the

design are Philips LXML Ph01.

WEBENCH LED DESIGNER proposes a list of

drivers suitable for such LEDs. Besides the driver IC

and the datasheet, an electrical circuit is proposed

for each driver. The drivers with the highest

efficiency are selected. Then they are compared for

their dimensions and price. The driver chosen for the

design is LM3424MH and the electrical circuit of

the design is presented on Figure 3.

4.2 Design of LED array 16x4

controlled by shift registers and

pseudo-random vector generator

The electrical circuit in ORCAD/Capture of the LED

array 16x4 controlled by shift registers and pseudo-

random vector generator (PRVG) is presented on

Figure 4. The 4 shift registers and the PRVG are

described in VHDL and simulated on CYPRESS

CPLD in WARP 6.2 (www.cypress.com). The

limiting current resistors R1-R64 from Fig. 3 are

calculated in the online calculator Ledz. From

Table_2.

Web Assisted Design of Communication Circuits and Systems

177

Table 1: Set of connections for Antenna design

Antenna Picture Calculator Web address in the Set of

connections

Log Periodic

antenna LPDA

Changpuak http://www.changpuak.ch/electronics/lpda.php

Radiohobby

http://radiohobby.hit.bg/antcalc.htm

Yagi antenna

Va3css

http://www.va3css.ca/calculators.html

Moxon antenna

Vp9kf

http://w4.vp9kf.com/moxon_design.htm

Jcoppens

http://jcoppens.com/ant/helix/calc.en.php

Helix antenna

Daycounter

http://www.daycounter.com/Calculators/Helic

al-Antenna-Design-Calculator.phtml

Microstrip patch

antenna

Emtalk

http://www.emtalk.com/mpacalc.php

Delta loop antenna

DxZone http://www.dxzone.com/catalog/Antennas/Ant

enna_Calculators/

66pacific

http://www.66pacific.com/calculators/small_t

x_loop_calc.aspx

Magnetic loop

antenna

Am-dx

http://www.am-dx.com/loop_calc.htm

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Table 2: Set of connections for LED array, controller and driver design

LED

calculator

Illustration Functions Web address in the Set of

connections

Ledz

Current

limiting

resistor

calculation for

one or several

LEDs

connected

serially or in

parallel

http://ledz.com/?p=zz.led.resistor.calculator

Ledlinear

LED

serial/parallel

array design

http://led.linear1.org/

LedCalculator

LED

serial/parallel

array design

http://ledcalculator.net/

LedCalc

array design

ttp://ledcalc.com/

LED

serial/parallel

LED Designer

calculation

.ti.com/ww/en/analog/webench/

led.shtml

EBENCH LED driver

circuit design

and efficien

http://www

MAX6952

controllers

atrix-display-using-lpt-port-and-driver-ic/

Programmin

LED

http://www.scienceprog.com/drive-dot-led-

Web Assisted Design of Communication Circuits and Systems

179

Table 3: Set of connect esign

tool Illustration Characteristic ress in the Set of

ions for SMPS d

CAD

or Portal s

Web add

connections

PowerEsim

S design –

Simulation tool

poweresim.com

Online platform for

SMP

www.

free

Transforme

calculator

WEBENC

POWER

DESIGNER

optimiza n

http ch.ti.com/webench5/power

Multiple circui

synthesis and

tio

://weben

SMPS

SMPS – all paid

ww .smps.com

PSpice projects fo w

le 4: ctio gn w

ols r

Tab Set of conne ns for Desi ith PSpice

Portal Characteristics CAD to Circuit

collection

Free

paid

Web address in the Set

of connections

eCircuitCenter

CEL 6

ww .ecircuitcenter.com

Project design

with EXCEL and EX

simulation with

PSpice

PSpice 115 projects

in 1

Free

categories

and

projects

ww .youspice.com

ORCAD

PSpice;

ap;

Micro-C

LTspice;

TINA;

EDWinXP;

Proteus;

NI Multisim

Altium

Designe

SPICE

OPUS.

392 projects

in 1

Free

Paid

72 free

SMPS SMPS projects PSpice

projects

Paid www.smps.com

SMPS

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180

Table 5: Set of connect trace estimation

Calculator Characteristic Illustration Web e Set of

ions for PCB

address in th

connections

Saturn PCB

Design

toolkit

v.5.6.

gnal

sing

current etc.

/www.saturnpcb.com/pcb_toolkit.

htm

Free downloadable

software for Via,

Conductor, Si

properties

calculation, P

impedance,

Thermal, Fu

http:/

TECHNIK

n for 7

geometries

hp?aiocp_dp=util_pcb_imp_

calculator

Impedance,

Inductanc

capacity

calculatio

different

http://www.technick.net/public/code/

cp_dpage.p

Selektronik

acity,

alculation

http://www.skottanselektronik.com/

Impedance,

crosstalk, current

carrying cap

thermo-via

Wordpress

, using

EXCEL

ind-pcb-trace-width-based-

on-power/

Trace Width

calculation based

on power

http://circuitcalculator.com/wordpress/2

006/04/20/f

EMCLAB

n for 4

geometries

http clab.mst.edu/pcbtlc2/

Trace impedance

calculatio

different

://em

EEWEB

n for 9

/or

striplines

lbox/microst

rip-impedance/

Trace impedance

calculatio

different

geometries o

microstrip,

striplines and

coupled and

embedded

http://www.eeweb.com/too

Web Assisted Design of Communication Circuits and Systems

181

Table 5: Set of connections for PCB trace estimation (continue)

TI PCB

THERMAL

CALCULATOR

Device junction

temperature

estimation

More than 200 TI

ICs supported

http://www.ti.com/adc/docs/midlevel.ts

p ?contentId=76735

Table 6: Set of connections for PCB design price estimation

PCB design price

calculator

Characteristics Web address in the Set of connections

MIKRON 20 Calculates the price of

PCB production and

assembly

http://www.micron20.com/bg/orders/calculator-

production/

http://www.micron20.com/bg/orders/calculator-

assembly/

SKA Prices for PCB

production are presented

in tables as well as

percentage for additional

services

http://www.cka-bg.com/index.php?page=tseni-

pechatni-platki&hl=bg_BG

MLAD

KONSTRUKTOR

Prices for PCB

production are presented

in tables

http://constructor.bg/shop/pcb_order_2.php

Figu 3.

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Figure 4.

The VHDL description of the 4 bit pseudo random

vector generator is:

The PRVG described in VHDL is simulated in

WARP 6.2 and the waveforms obtained are

presented on Figure 5. The input is the clock signal

and the 4-bit vectors generated are obtained at

random_4bit. The random numbers are presented in

decimal form.

library IEEE;

use IEEE.STD_LOGIC_1164.ALL;

entity rng is

generic ( wd : integer := 32 );

port (clk : in std_logic;

random_num : out std_logic;

random_4bit: out

std_logic_vector (3 downto 0));

end rng;

architecture Behavioral of rng is

signal rand_temp : std_logic_vector(wd-1

downto 0);

signal temp : std_logic;

begin

process(clk)

begin

if(clk'event and clk='1') then

temp <= not(rand_temp(wd-1) xor

rand_temp(wd-2));

rand_temp(wd-1 downto 1) <=

rand_temp(wd-2 downto 0);

rand_temp(0) <= temp;

end if;

end process;

random_num <= rand_temp(wd-1);

random_4bit(3)<= rand_temp(wd-1);

random_4bit(2)<= rand_temp(wd-2);

random_4bit(1)<= rand_temp(wd-3);

random_4bit(0)<= rand_temp(wd-4);

end Behavioral;

Figure 5.

The functionality of the circuit from Figure 4 is

presented on Figure 6, where red circles indicate

lighting LEDs.

Web Assisted Design of Communication Circuits and Systems

183

Figure 6.

This design is a good illustration of the

advantages of combined utilization of Local

resources as WARP 6.2 and online calculator as

Ledz.

5 CONCLUSIONS

The paper illustrates the concept of a Portal with

Web assistants, developed to help the solutions of

The Web assistants are composed by Sets of

connections with Useful web resources and e-

Content. The research work concerning 6 tasks for

CAD is presented in the paper and the Sets of

connections with online calculators and other web

resources of the Web assistant in the Portal are

considered in details. Two examples of LED design

are described in order to illustrate the approach.

Further work is planned in order to enlarge the

Portal with new Web assistants and new Sets of

connections for solving new Tasks for CAD in

communications.

Tasks for computer aided design in communications.

REFERENCES

Marinova, G., June 2012, Multitool online assisted

disciplinary approach

for

2012, PSpice as a

Ver

http l

design of communication circuits and systems,

ICEST’2012, Veliko Tarnovo

Marinova, G., 2010, Multi

teaching Computer-Aided Design in

communications using multiple software tools,

Advanced Aspects of Theoretical Electrical

Engineering Sozopol '2010, Sozopol, Bulgaria,

Plenary lectures, pp. 34 -42

Marinova, G., July

ification Tool for Switch Mode Power Supply

Design with PowerEsim, NDES’2012, Wofenbuttel,

Germany, pp.140-143, ISBN:978-3-8007-3444-3

MARTINDALE’S Calculators Online Center

://www.martindalecenter.com/Calculators.htm

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