IEEE 802.15 <subject>

1
Project IEEE P802.15 Working Group for Wireless
Personal Area Networks (WPANs) Submission Title
TG3a-Wisair contribution on multi band
implementation Date Submitted 5 May,
2003 Source Gadi Shor Company
Wisair Address 24 Raoul Wallenberg st. Ramat
Hachayal, Tel-Aviv, ISRAEL Voice
972-3-7676605 FAX [phone], E-Mail
gadi.shor_at_wisair.com Re 802.15.3a Call for
proposal Abstract Wisairs contribution on
multi band implementation issues Purpose
Response to questions from TG3a
members Notice This document has been prepared
to assist the IEEE P802.15. It is offered as a
basis for discussion and is not binding on the
contributing individual(s) or organization(s).
The material in this document is subject to
change in form and content after further study.
The contributor(s) reserve(s) the right to add,
amend or withdraw material contained
herein. Release The contributor acknowledges and
accepts that this contribution becomes the
property of IEEE and may be made publicly
available by P802.15.
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Multi-BandImplementation Issues
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Contents

• Multi band generator
• Requirements
• Band Plan
• Design example
• Design considerations
• Lo leakage

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MultiBand Generator

• Many possible architectures
• Digital based
• Analog Based
• Combined approaches
• Can be implemented using either SiGe or CMOS
  process
• Low power consumption / Small die size

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Requirements

• 3.79 nSec between pulses in 132 Mpps
• Back to back pulses in 264 Mpps
• Better than 20 dB in adjacent sub-band
• Better than 25 dB in other sub-bands
• Rejection of out of band harmonics (To simplify
  UWB filter requirements)

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Band Plan

• Two frequency groups A B
• 220 MHz frequency shift between groups
• 440 MHz separation between sub-bands
• 538 MHz sub-band bandwidth

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Design Example

• Example of combined digital and analog
  implementation
• Example is scalable with required pulse rate
• Supports requirements for 132 Mpps and 264 Mpps
• Covers lower set group A which allows up to 480
  Mbps
• To support group B additional division and
  multiplication is required
• Future systems can use upper set with additional
  PLL and the same sub-band generator to support 1
  Gbps

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MultiBand Generator 132 Mpps
2mW
DC
18mW
440 MHz
Chip Rate Clk 1056 MHz
880 MHz
MUX
Sub-Band
5 1
5280 MHz
1320 MHz
Generator
1760 MHz
10mW
12, 19.2, 20 MHz and others
9mW
5280 MHz
MultiBand Generator Out
SSB U/L

• Power Consumption of 132 Mpps MultiBand
  Generator 39 mW

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Sub-Band Generator
- Simple, low power consumption design - Based on
mature radio technology
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Single Sub-Band Spectrum
Adjacent sub-band is 23 dB down relative to main
sub-band
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MultiBand Generator 264 Mpps(Back to Back Pulses)
3mW
18mW
DC
440 MHz
Chip Rate Clk 1056 MHz
880 MHz
MUX
Sub-Band
5 2
Generator
5280 MHz
1320 MHz
10mW
1760 MHz
9mW
12, 19.2, 20 MHz and more
5280 MHz
SSB U/L
MultiBand Generator Out
9mW
SSB U/L

• Power Consumption of 264 Mpps MultiBand
  Generator 49 mW

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264 Mpps MultiBand Signal
Switching is done when pulses amplitude is close
to zero Realistic switching time has negligible
effect on pulse shape
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Design Consideration

• Design requires generation of I and Q components
• Achieved through 50 duty cycle and divide by 2
• Out Of Band rejection filter (1.8 GHz)
• On chip design for I and Q
• Matching requirements are reasonable (e.g. 25 dB
  image rejection)
• Switching effects minimized by use of dual SSB
  mixers and signal shape
• Switching effects can be seen in the next slide

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Switching effects
Negligible degradation under realistic switching
time 500pSec -gt 0.1 dB relative
degradation 750pSec -gt 0.2 dB relative
degradation
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LO Leakage

• LO leakage need to be considered to avoid
  problems with FCC mask
• LO attenuation is better when LO goes through
  several mixers
• Each mixer gives 25-30 dB
• Only one real LO in the example design
• Sub-band frequencies are not in-band signals
• Allows traditional techniques as used for
  non-hopping LO suppression
• Benefits from heterodyne like design (e.g. 2
  mixers in a row)

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Summary

• Multi band generator can be implemented in many
  ways
• Requirements are set to allow reasonable
  implementation