enhancing ubiquitous communications: the -sat...

Enhancing ubiquitous communications:

the -Sat challengeLuciano Boglione

US Naval Research Laboratory

2018 RWW/IoT Symposium

Agenda

1. Setting the -sat stage• Connecting together• Space environment

2. Enhancing the comm link• Full‐duplex systems• The NRL approach• Result overview

3. Conclusions

Luciano BoglioneEnhancing ubiquitous comms…

Slide 2


Internet of Things

Communication links are pervasive in an IoT world

Power requirements are key for ubiquitous

interactivity

MonitoringMonitoring TrackingTracking

ServicesServices

Slide 3

-sat challenge

Available Payload Size10 cm x 10 cm x 16.5 cm2.33 kg

Available Power~ 8 Watts Orbital Average (Entire Satellite)

Making the Most of Limited Size, Weight and Power


Slide 4

-sat receivers

GLADIS Nano‐Sat Payload Data‐X Receiver Currently on International Space StationFrequency Range: 385 – 410 MHzDynamic Range: 86 dBSize: 15.2 cm x 15.2 cm x 1.8 cmWeight: ~ 400 gramsPower: 1.7 WattsRadiation Tolerance: 12 KradsOutput: raw 16‐bit digitized data

• QBX1 Receiver: NUU‐100– Launched December 2010 – Frequency Range: 420 – 450 MHz– Dynamic Range: 80 dB– Size: 9 cm x 9.6 cm x 1 cm– Weight: ~ 250 grams– Power: ~0.5 Watts– Radiation Tolerance: 5 Krads– Output: demodulated Frequency Shift Keyed

(FSK) bit stream

9.6 cm 15.2 cm

15.2 cm

9 cm


Slide 5

An obvious solution?


Slide 6

Cellphone limitations

1. Not Radiation‐HardenedCell phones do not require radiation tolerance

2. Lacks Desired FlexibilityTunability is hardwired into devices• Internal noise spurs must be kept out of bands of interest

3. Insufficient Dynamic Range• Dynamic range is sufficient for terrestrial cellular comm,

but not for terrestrial to space communication

Comm systems must meet competing requirements

Low‐Power + Radiation Hardness + Flexibility + High Dynamic Range


Slide 7

Radiation spaceSpace Radiation Environment• Solar particle• Cosmic rays• Radiation belts

Effects on ICs of Radiation Exposure• Total Ionizing Dose (TID)• Single Event Effects (SEE)• Displacement Damage (DD) – primarily issue for solar panels

Tools at NRL for Simulating Radiation• rays from Co60 (TID)

• Pulsed Laser (SEE) – NRL unique


Slide 8

• Radiation environment consists of protons, electrons and heavy ions in radiation belts around the earth, as well as solar particles and cosmic rays.

• All radiation particles originate in the sun or in deep space.

• Radiation exposure depends on orbit, mission duration and launch date.

Radiation highlights

Radiation belts around the earth

Particles originate in the sun and deep space


Slide 9

• Cumulative destructive effects include total ionizing dose (TID) in gate and field oxides/insulators and displacement damage dose (DDD) in semiconductors.

• Single ions randomly striking the IC or optical component can produce single event effects (SEEs) via ionization that can be destructive (burnout) or non-destructive (loss of information).

Radiation effects

Ion strike location determines effect


Slide 10

SEE are more prevalent as devices scaled down in size

• SEEs can occur in parts used in space and on earth (neutrons from cosmic rays)

• SEE testing requires particle accelerators that are expensive ($1500/hr to $4500/hr) and access is limited.

• Alternate methods of SEE testing have been developed such as pulsed laser systems.

Radiation assessment


Slide 11


• Shielding reduces TID.• Limited shielding on most Small Satellites due to small size.• Shielding less effective against SEEs.

Total Ionizing Dose• Shielding• Process modifications

such as minimizing hydrogen and lowering temperature.

• Design modification such as reducing gate insulating thickness

Single Event Effects• Error detection and

correction• Triple modular

redundancy with voting and scrubbing

• Adding filters to circuits• Using “silicon-on-

insulator” or epitaxial silicon wafers

Radiation mitigation –in general…

Slide 12

Design rad-hard IC

• Expensive• At least two

generations behind state-of-the-art in performance

• Challenging in a research lab environment

Use COTS parts

• Screening parts for TID and SEE

• Adding unbiased spares

• Using watchdog timers1. to monitor circuit2. to recycle power when

SEE detected• Eliminate single

event transients

Radiation mitigation –… and for -sats


Slide 13

Techniques can• increase the circuit

radiation tolerance at the transistor level

• allow use of commercial, high-performance semiconductor processes in radiation environment

Design targets• RF circuitry is

radiation-tolerant• Digital circuits are

radiation-sensitive• Enhance single event

upset (SEU) immunity

• Enhance total dose radiation tolerance (if process requires)

Rad-Hard by Design


Slide 14

Simultaneous Transmit And Receive

Full Duplex comms @ NRL(STAR)


Slide 15

• Tune over the microwave range with 1 GHz of instantaneous bandwidth

• Operate in presence of co-located transmitter with >1kW of ERP

• Have high isolation antennas• with minimal form

factor• With an innovative

architecture optimized for• Broadband

cancellation• SWaP constrained

platforms

Technical Objectives

NRL has been funded by ONR to investigate and deliver a full‐duplex STAR system that can


Slide 16

Conventional Solutions

Upconverters

High Power Amplifiers

Transmit Antennas

Downconverters

Low Noise Amplifier(s)

Receive Antennas

Digital‐to‐Analog

Equalization

Analog Canceller

LO(s)

Separate Tx/Rx Antennas

Upconverters

High Power Amplifiers

RF circulator / Optical isolator

Downconverters

Low Noise Amplifier(s)

Digital‐to‐Analog Analog‐to‐Digital

Equalization

Analog Canceller

LO(s)

1 23

Single Tx/RxAntenna

Pros: Isolation improves with distance, material, patternCons: Form factor

Pros: Form factor, no other solution for commsCons: Limited isolation

Analog‐to‐Digital


Slide 17

Team effort led by NRL• RF isolation ➤ new antenna system (CUB)• Novel digital cancellation (NRL)• High performance ADC (OSU)• Upgradable architecture (NRL)

NRL Solution


Slide 18

Antenna configuration

By Prof. Filipovicteam @ CUB

2‐7 GHz 18‐45 GHz 6‐19 GHz

17 in

17 in


Slide 19

2-7 GHz Isolation

By Prof. Filipovicteam @ CUB


Slide 20

Receiver hardware


Slide 21

Prototype & RFIC

1. Extensive RX chain analysis• Frequency planning to meet DSP algorithm

requirement• Noise vs. linearity trade‐offs• Guide RFIC design

2. System insensitive to choice of TX components


Slide 22

RFIC highlights

Full-duplex IC SoC• GF 8HP SiGe BiCMOS

C4 finish (flip-chip)• RX chain with SPI

control• Analog gain• ADC control• On‐chip lumped element

2GHz differential filter


Slide 23

LNA

OIP3

SS


Slide 24

First mixer

Relatively constant OIP3 vs. gain


Slide 25

On-chip filter


Slide 26

On-chip ADC

VGA

= .

=

.

Resistor ladder and reference

buffers

Main track and hold

Test Port

5.532 GHz Clock Input

Serializer and LVDS Drivers

SPI interface logic

Time‐interleaved ADC slices

By Prof. Khalil team @ OSU


Slide 27

Board deployment


Slide 28

Prototype System

• Prototype demonstrates operation of NRL’s full-duplex system• Off‐the‐shelf components used to

define prototype receiver• Operation characterized in lab with

realistic environment features


Slide 29

RF Receiver


Slide 30

Lab demonstration


Slide 31

Anechoic chamber


Slide 32

20

25

30

35

40

45

50

‐40 ‐35 ‐30 ‐25 ‐20 ‐15 ‐10 ‐5 0

P OUT

(dBm

)

PIN (dBm)

TX distortion

Operating well beyond 5 dB compression point


Slide 33

RF Receiver

Signal GeneratorsData Generation (DAC)Data Capture (ADC)

100 200 300 400 500 600-100

-90

-80

-70

-60

-50

-40

-30

-20

-10

0

Frequency (MHz)M

agni

tude

(dB

)

2nd order2nd complex3rd order3rd complex4th order5th orderInterleaved2nd polyphase3rd polyphase4th polyphase5th polyphase

> 20dB

NRL RX test-bed• Tunable custom NRL

RF Receiver• 12-bit ADI pipelined

ADC

NRL compensation pushes distortions down by 20 dB in the range -70 to -80dBc• FPGA-implemented

Nonlinear Compensation


Slide 34

Performance demo (I)COMM SIGNAL

RADAR SIGNAL No multipath, digital cancellation


Slide 35

Performance demo (II)


Slide 36

Performance demo (III)


Slide 37

Performance demo (IV)


Slide 38

Wrap-up

• Interconnectivity means C-SWaP• Full‐duplex as additional dimension in

the IoT space

• NRL full-duplex solution• Demonstrated state‐of‐the‐art• Well suited to address space‐limited

platforms


Slide 39

Acknowledgment

• Office of Naval Research• Dr. Brad Binder, ONR, Code 31• Dr. Kevin Rudd, ONR, Code 31• Dr. Daniel Green, ONR, Code 31

• US Naval Research Laboratory• Electronics Science & Technology Division, NRL,

Code 6800• Solid‐State Circuits Section, NRL, Code 6851• Joel Goodman and his team, NRL, Code 5731• Kenneth Clark, NRL, Code 8120• Stephen Buchner, NRL, Code 6816


Slide 40

enhancing ubiquitous communications: the -sat...

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