UWB Pulse Based Test-Beds for Communication and Radar

IME

UWB Pulse Based Test-Beds for

Communication and Radar

Thomas BucheggerLinz Center of Mechatronics - ICIE

Alexander ReisenzahnUniversity of Linz – IME

UWB Pulse Based Test-Beds for Communication and Radar

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Outline

• UWB Communication Test-Beds– Human Tissue Penetrating

Radio Link Prototype• Cochlear Implant Application

– PPM Test-Bed with Synchronization– Phase Modulated Transmitted Reference

Systems

• UWB Radar


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Communication Test-Beds


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Human Tissue PenetratingRadio Link Prototype• Modulation: On-Off Keying

• PRF: 40 MHz

• Data rate: 1.2 Mbps

• Range: 1 m

• Receiver: non-coherent detector

• Power consumption (Rx): 20 mW Rx with Backward Diode: 0 mW

UWB transmitter UWB detector receiver


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Human Tissue PenetratingRadio Link Prototype – The Chochlear Implant Application

outside componts of a chochlea implant

• high power consumption• optical unfavorable

UWB transmit signal


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UWB PPM Test-Bed with Synchronization

receiver

local oscillator

channeltransmitter

UWBtransmitter

external clock(Information)

radiochannel

PDLNA

PD

LP OPA ADC

microcontroller

DDSUWB

reference pulse

oscilloscop

• block schematic of the prototype


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Results:

UWB PPM transmitterstep recovery diodesdata rate of 10Mbps

UWB PPM coherent receivercorrelation ReceiverDDS for synchronization

Synchronization algorithm:clock synchronization

< 100 ppm data synchronization

< 5 ms UWB PPM and OOK test bed


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Pulse-Based Modulation Schemes1 0 1

Amplitude

t

0 1 0

t

Amplitude

0 1 0

t

Amplitude

0 1 0

t

Amplitude

0 1 0

t

Amplitude

0 1 0

t

Amplitude

t

s1, s2 = 0, 0 0, 1 1, 0 1, 1

Amplitude

On-Off-Keying

Pulse Amplitude

Pulse Position

Pulse Phase

Delay Hopped Transmitted Reference (DHTR)

Phase Modulated Transmitted Reference (PMTR)

Enhanced Phase Modulated Transmitted Reference (EPMTR)


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PMTR UWB Systems

• Fast and easy synchronization with an integrating controller

• Only one broadband mixer in the receiver

• One pulse per bit


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EPMTR Transmitter and Receiver


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Simulation – DHTR, PMTR, EPMTR Systems

Comparison in AWGN channel

DHTR in CM1 with 10 Mbps

PMTR in CM1 with 10 Mbps


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PMTR - Hardware – Test-Bed

R2

C1

GND

Uin

R1 R3

C2

GND GND GND

+3,3 V +3,3 V

R5

C3

R4 R6

GND GND

C4

GND GND

Uout

+3,3 V +3,3 V

T2T1

Stichleitung0,5 mm dick1 mm lang

Stichleitung0,5 mm dick1 mm lang

PMTR transmitter

Pulse generator of an UWB PMTR system

Transmit pulses of a PMTR system


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Radar Test-Bed


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UWB-Radar Test-Bed Principle

PCUSB

ControllerTransistor

Pulse Generator

Direct DigitalSynthesizer

DownConverter

ADC

Target

TXAntenna

RXAntenna

LNAAmp.

Radar test-bed block diagram


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Transmitter – Pulse generation with D-Latch and single bipolar transistor

CLK

D

Q

PR

CLR

Q

R1

+3.3V

+3.3V

CLK In

Pulse Out

StubC1

• TTL-outputsignal drives transistor into saturation

• Due to the step recovery effect a steep rising edge at the collector is generated

• Differentiation with a short circuited stub

• Elimination of the negative components with a clipping diode

Pulse generation circuitry


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Transmitter – Pulse generation with D-Latch and single bipolar transistor

Output pulseSpectrum of the output pulse combined with the FCC indoor radiation mask


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Receiver – Sequential Sampling

time

amplitude

tPR

tPL

tSample

max2

1

ftt PRSample


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Receiver - Sampling Phase Detector

• Step recovery diode generates step functions• Capacitors differentiate the steps to pulses and act

as a filter for low frequencies• Schottky diodes are turned on by the pulses

SPDLO-IN RF-IN

IF-OUT


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Receiver – Down Conversion

Pulse original Pulse downconverted


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Measurements

Conversion gain 1-dB compression point


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Measurements

Propagation delay

•1 dB-Compression Dynamic Range: > 42 dB

•Receiver Sensitivity: -43 dBm


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UWB Radar Test-Bed

• No biasing• Low cost off the shelf

components• FR4 PCB-material• Single 5 V power supply• Data transfer with USB-

interface

Radar test-bed


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Receiver – Downconverter with SPD

LO-IN RF-IN

SPD

OUT

LOW PASSFILTER

L

Down converter circuitry with SPD


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Receiver – Downconverter Bandwidth

• Bandwith is depending on the sampling pulse duration:

• Pulse duration approximately the transit time of the SRD

GHz350

max psintf

GHz4,6

55

max

f

pstT


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Transmitter - Pulse Generation

• D-Latch combined with step recovery diodes (SRD)

• D-Latch combined with a single bipolar transistor


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Transmitter - D-Latch with SRD

C1 C2 C3

+5V

L1

D2

D1

I1 I2

in out

GND

• Both SRDs biased in forward direction

• D1 used for steepening the rising edge

• D2 used for steepening the falling edge

• Capacitors for DC-decoupling


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Transmitter - D-Latch with SRD

TTL Pulse

UWB Pulse

Input- and Output-Pulse Prototype


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...

f

U

PRFf

1

...

POSt

MCt

U

f

PRFPRF ft

1

fPRF = 10 MHz

tMC = 750 ns

tPOS = 38 ps

f = 507 Hz

pulse repetition time

necessary new pulse repetition time for a pulse shift of tPOS is used within the time tMC.

example:

PRF

POS

PRFnewPRF ft

t

ft

MC,

1

PRFMC

POS

PRF

PRF

ft

t

f

ff

1

1

TemplateSignal

Rx Signal


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EPMTR Transmitter and Receiver

Documents

UWB Pulse Based Test-Beds for Communication and Radar