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AN9949

ISL36342U-EVAL PRISM II 11Mbps USB Wireless

LAN Evaluation Kit User’s Guide

Introduction

This kit allows evaluation of the

Intersil PRISM® II Direct Sequence

chip set design in a Wireless Local

Area Network (WLAN) USB Card implementation.

Software drivers are included allowing data to be transmitted

between cards at 1, 2, 5.5 and 11Mbps transfer rates, with a

diagnostic program to display the real data throughput from

system to system.

Included in the kit are PRISM II chip set data sheets with

application notes describing the implementation of a

wireless networking card using the chip set.

Contents of Your Evaluation Kit

Your PC Card Wireless LAN Evaluation Kit contains the

following items:

Should you discover that your PC Card Wireless LAN

Evaluation Kit is incomplete, please contact Intersil

Corporation.

Overview of IEEE 802.11

The IEEE 802.11 specification is a standard for wireless

connectivity for fixed, portable, and moving stations within a

local area.

The IEEE 802.11 standard describes the services required

by a compliant device to operate within an “ad hoc” or

“infrastructure” network, as well as dealing with the issues

related to mobility within those networks. Spread spectrum

techniques are used to tolerate mobility and multipath

effects. They are also a requirement for compliance with

FCC, ETSI and those of other regulatory authorities when

operating within the Industrial, Scientific, and Medical (ISM)

frequency band.

An ad hoc communications network is created quickly and

informally for a temporary time period. An infrastructure

network usually requires more planning so that wireless

stations can communicate over longer distances through

access points, and may also communicate with existing

wired LANs using portals.

The IEEE 802.11 standard describes Media Access Control

(MAC) procedures. The principal method of communication

is the Carrier Sense Multiple Access with Collision

Avoidance (CSMA-CA) protocol. Using this protocol, each

station senses the communications medium (RF channel),

and does not transmit until the channel is clear. This avoids

collisions and minimizes the retransmission of subsequent

packets.

The standard also supports the operation of a station within

a wireless LAN that may coexist with several overlapping

wireless LANs. To accomplish this, a scheme of

channelization and spread spectrum techniques is used.

Direct Sequence (DSSS) and Frequency Hopping (FHSS)

spread spectrum techniques are supported by the standard

and both operate in the 2.4GHz to 2.4835GHz frequency

band (the unlicensed ISM band). An infrared technique is

also supported for indoor applications. The standard

supports a 1Mbps and 2Mbps data rate for both DSSS and

FHSS and has recently introduced a high data rate standard

supporting 5.5Mbps and 11Mbps DSSS using

Complementary Code Keying (CCK) modulation.

The standard has also specified the requirements and services

that enable private and secure communications to occur.

Wireless LAN Configurations

For ease of use in evaluating these cards, an ad hoc

network for peer to peer communications can be created.

An ad hoc network is usually created for a specific purpose

(such as file transfer or accessing a database). Ad hoc

networks simplify the process of creating and dissolving

networks for nontechnical users of the network facilities.

Two cards form an IEEE 802.11 Independent Basic Service

Set (IBSS), the simplest ad hoc network. The cards

communicate with each other directly and must remain

within radio range. When both cards are on, they

immediately “see” each other and the ad hoc network is

formed without user intervention.

TousethecardsinaninfrastructureBSS(alsocalledan

Extended Service Set) where the two cards may not be in direct

radio contact, access points are needed. The association

between a card (station) and an infrastructure BSS - where

communication occurs only between a station and an access

point and not between stations directly is dynamic.

QUANTITY DESCRIPTION

2 PRISMIIWirelessLANPCCards

1 ISL36342U Wireless LAN Evaluation Kit User’s

Guide, AN9949

1 PRISM II Chip Set Data Sheets

1 PRISM II Application Notes

1 Microsoft® Windows® 98, 98SE, MS, Win2000

Drivers

1 PRISM® Test Utilities (PTU) Software

1 Features/Benefits Card

1 Product Registration Form

1 Notification Card

Application Note June 2001

Author: Richard L. Abrahams

1-888-INTERSIL or 321-724-7143 | Intersil and Design is a trademark of Intersil Americas Inc.

PRISM® is a registered trademark of Intersil Americas Inc. PRISM and design is a trademark of Intersil Americas Inc.

Microsoft® Windows® and Windows NT® are registered trademarks of Microsoft Corporation. LINUX® is a registered trademark of Linus Torvalds.

Summary of content (12 pages)

PAGE 1
ISL36342U-EVAL PRISM II 11Mbps USB Wireless LAN Evaluation Kit User’s Guide TM Application Note June 2001 AN9949 Author: Richard L. Abrahams Introduction This kit allows evaluation of the Intersil PRISM® II Direct Sequence chip set design in a Wireless Local Area Network (WLAN) USB Card implementation. Software drivers are included allowing data to be transmitted between cards at 1, 2, 5.5 and 11Mbps transfer rates, with a diagnostic program to display the real data throughput from system to system.
PAGE 2
Application Note 9949 The IEEE 802.11 protocols are implemented in the firmware so that file transfers or database access can begin immediately. Direct Sequence Spread Spectrum Approach The use of spread spectrum techniques for wireless computer communications is widely accepted because of its robustness against multipath effects and interference from intentional or unintentional radiators.
PAGE 3
Application Note 9949 PC Card Evaluation This chapter describes several software programs supplied with the kit. It also details some diagnostic test points that may be accessed on the card. Using the PRISM Test Utility (PTU) Software The PTU permits continuous operation of the transmitter. It is therefore convenient for performing RF measurements such as Transmitter Power.
PAGE 4
OSC 44MHz HFA3983 (FILE #4635) PA PLL VCTRL VCO BUFFER RF LO HFA3683A (FILE #4634) RF/IF CONVERTER I/Q LO VCO IF LO TX DAC TX ADC Q DAC I DAC TX ALC MOD AND FILTER I/O RAKE AND DEMOD AGC CTL CONTROL TEST I/O 6 7 6 6 6 6 1 6 1 FIGURE 1. WIRELESS LAN PC CARD BLOCK DIAGRAM VCTRL HFA3783 (FILE #4633) IF I/Q MOD/DEMOD PLL REF_OUT Q ADC I ADC RF DAC RF ADC IF DAC HFA3863 BBP (FILE #4868.
PAGE 5
TP6 J3 TP3 TP9 C149 TP1 C131 USB Attached P1 TP7 R85 L26 TP2 TP4 C119 C64 X1 C148 TP5 USB D- USB D+ C152 C122 C138 TP10 R95 R72 R92 C146 R90 C4 TP14 Q1 TP11 TP15 C147 vReg +3.
PAGE 6
C65 FL3 L4 C66 R43 R73 C83 R37 C60 C67 C114 R51 C54 L8 C101 C98 L11 C105 R46 R53 C77 C151 C97 C130 U13 C133 U15 C100 C136 C50 C135 R44 R75 R76 C109 C69 R77 C62 C117 C116 C23 R65 C123 C125 R69 C95 C94 R35 C115 FL5 C113 R60 R68 R71 C126 C128 L19 L20 C127 L2 FIGURE 3. WIRELESS LAN PC CARD TEST POINTS (BOTTOM VIEW) C137 R55 TEST POINT F - RF L.O. TEST POINT G RF L.O.
PAGE 7
Application Note 9949 HFA 3683A HFA 3783 Diversity Switch UPG-152TA 1dB IL OCP 27 OIP3 50 Lowpass Filter LTF3216L 1dB IL Bandpass Filter USN 30172450 2dB IL LNA/Image Rejection Mixer Gain 25 dB NF 3.7dB OCP -7.5 OIP3 12 T/R Switch UPG-152TA 1dB IL OCP 27 OIP3 50 374MHz Saw Filter 8.5dB IL HFA 3783 Gain 61 NF 7dB OCP -14.3 OIP3 1.5 FIGURE 4. Receiver Noise/Gain Analysis The ISL36342U is implemented on FR-4 material. It uses 50Ω coplanar micro-strip traces which have a loss of 0.35dB/in at 2.442GHz.
PAGE 8
Application Note 9949 TABLE 1. HIGH GAIN PARAMETERS PART REFERENCE NF GAIN OCP OIP3 CUM NF CUM GAIN ICP OIP3 IIP3 UPG152TA 2 -2 27 50 2.00 -2 29 50.00 52.00 LTF3216L 1 -1 99 99 3.00 -3 29 49.00 52.00 LFSN30172450 2 -2 99 99 5.00 -5 29 47.00 52.00 UPG152TA 2 -2 27 50 7.00 -7 29 43.81 50.81 HFA3683A 3.7 25 -7.5 12 10.70 18 -25.5 12.00 -6.00 SAW374M 8.5 -8.5 99 99 10.74 9.5 -25.5 3.50 -6.00 HFA3783 7 61 -14.3 1.5 10.90 70.5 -84.8 1.
PAGE 9
Application Note 9949 The I and Q are both differential signals and, as such, consist of I+, I-, Q+, and Q- respectively. As these are balanced signals, data is measured using a Tektronix P6247 Differential Probe. For example in the measurement of the I signal, the probe is bridged between Test Points A (I+) and A1 (I-).
PAGE 10
Application Note 9949 Test Points F and G Test Point J RF local oscillator (LO): IF Receive Signal: FIGURE 11. RF LOCAL OSCILLATOR OUTPUT AT CHANNEL 8 (TEST POINT F) The behavior of the RF VCO can be monitored at Test Point F. The VCO output should be locked at the channel frequency minus the IF (374MHz.) This means that the VCO will have to lock between 2038MHz and 2110MHz. The output power at test point F is approximately -6dBm. Ideally, the tuning voltage of the VCO, when locked, falls between 0.
PAGE 11
Application Note 9949 The receive In-phase and Quadrature (I and Q) signals are the demodulated lowpass-filtered data that are coupled to the HFA3861. The output levels of these two signals are approximately 500mVP-P. As these are balanced signals, data is taken using a Tektronix P6247 Differential Probe. • Test point K for RXI+ signal is at the 0Ω jumper, R19. • Test point K1 for RXI- signal is at the 0Ω jumper, R23 TABLE 4.
PAGE 12
Application Note 9949 interference to radio or television reception, which can be determined by turning the equipment off and on, the user is encouraged to try to correct the interference by one or more of the following measures: WARNING! Any changes or modifications of equipment not expressly approved by Intersil could void the user’s authority to operate the equipment.