MURI Review Agenda (Morning)

Transcription

1 MURI Review Agenda (Morning) 9:00 AM: Opening comments -- Bob Ulman, US ARO 9:05 AM: Introduction to the UWB MURI Research Effort -- Bob Scholtz 9:20 AM: Algorithm and System Architecture Studies Panel: Keith Chugg, Dennis Goeckel, Won Namgoong, Bob Scholtz, David Tse, Dana Porrat, Bob Weaver Topics: UWB Acquisition and Tracking, Channelized UWB Receivers, Alternatives to Selective Rake, UWB Frequency Domain Processing, Capacity Limits of UWB Impulse Radios 10:35 AM: Break 10:45 AM: Antennas and Propagation Topics: Simulation of UWB Antennas and Circuits, UWB Link Budgets, Antennas for UWB, Optimal Waveform Studies, UWB Synthesizer Project Panel: Dan Schaubert, David Pozar, Won Namgoong, Bob Scholtz, Anatoliy Boryssenko 12:00 PM: Lunch Break UMass Antenna Lab USC UltRa Lab UC Berkeley BWRC

2 UMass UWB Link Simulator:: Electromagnetic, Circuitry & Communication Scenarios The UMass UWB Link Simulator has been developed to address challenging electromagnetic topics of the MURI UWB Short-Range Radio Project Antenna and Pulse Optimal Co-Design Antenna T/R Circuitry Co-Design EMC & Coexistence of UWB and CW systems Link Budget and Capacity Estimates Satisfaction of the FCC Regulations Multipath Pulse Distortion Mobile Communication Operation Statistics of Multipath, Crosspol Disturbance of antennas by nearby bodies Through Matter Propagation (future step) UMass Antenna Lab Anatoliy Boryssenko, Dan Schaubert USC UltRa Lab UC Berkeley BWRC

3 UMass UWB Link Simulator:: Preprocessor, Engines and Postprocessors The UMass simulator supports GUI opportunities for all operational stages Preprocessor Engines Postprocessor Geometry Materials Link Scenarios Freq Domain Time Domain SPICE Integration Antennas Tx/Rx Circuitry Link Performance UMass Antenna Lab Anatoliy Boryssenko, Dan Schaubert USC UltRa Lab UC Berkeley BWRC

4 UWB Link Simulator Includes the Following Elements Antennas Signals Environment Circuitry Anatoliy Boryssenko, Dan Schaubert

5 Pulse Optimization for Reception and Flat Spectral Density of Radiated Signals? Which antenna geometries are best? Which waveforms are best? shape? Determine pulse shapes optimal for generation, radiation & reception Determine simple canonical pulse shapes suitable for generation through hardware Study effects of spectrum control to meet FCC regulation shape? spectrum Anatoliy Boryssenko, Dan Schaubert

6 Pulse Optimization for Bow-Tie Antenna Link:: Flat Spectrum GHz vs. Sharp Pulse Shape Flat spectrum for radiated field - meet the FCC regulation Flat spectrum for Rx load voltage results in a sharp pulse ~ 6-nanosecond pulse Mutually exclusive goals? Complexity of generation? Anatoliy Boryssenko, Dan Schaubert

7 Pulse Optimization for Rhombus Antenna Link:: Flat Spectrum GHz vs. Sharp Pulse Shape Flat spectrum for radiated field - meet the FCC regulation ~ 6-nanosecond pulse Flat spectrum for Rx load voltage results in a sharp pulse Mutually exclusive goals? Complexity of generation? Anatoliy Boryssenko, Dan Schaubert

8 Mathematical Pulses in Bow-Tie Antenna Link:: Shape Simplification Rayleigh Pulse Triangular Pulse ~ 6-nanosecond pulse ~ 2-nanosecond pulse Shape generation? Spectrum control? Anatoliy Boryssenko, Dan Schaubert

9 Quantization of Optimal Pulses in Bow-Tie Antenna Link:: Simplifying Generation ~3-bit amplitude resolution with 150-picosecond sampling Hardware implementation? Spectrum control? Anatoliy Boryssenko, Dan Schaubert

10 ±1 Bipolar Optimal Codes to Generate Pulses in Bow-Tie Antenna Link:: H-Bridge Driving An optimal code with 175-picosecond wide elements [ ] Further optimization? Spectrum control? Anatoliy Boryssenko, Dan Schaubert

11 Pulse Distortion Because of Operational Complexity:: Multipath, Blockage, Near-Field Effects, Mobility. What is difference compared with undisturbed far-field cases? What are effects of pulse distortion and echos? How severe are particular cases? How the above phenomena effect the system design? Moving trajectory How to minimize the impact through co-design of antennas and signals? Are statistical estimates required? Anatoliy Boryssenko, Dan Schaubert

12 Effect of Link Node Mobility and Cavity in Dipole Antenna Link Optimal pulse:: Free space Optimal pulse:: Position #3 Pos #1 Pos #2 Pos #3 Pos #4 Moving trajectory Anatoliy Boryssenko, Dan Schaubert

13 Multipath in Bow-Tie Antenna Link Disturbed by Cavity:: Different Transmit Pulses Optimal pulse Optimal quantified pulse code Anatoliy Boryssenko, Dan Schaubert

14 Blockage Effect in Rhombus Antenna Link by 80x80 cm Conducting Square Plate Free space Plate between Anatoliy Boryssenko, Dan Schaubert

15 Simulation of Antennas and Circuits through Interface between EM TDIE and SPICE Engines Full-wave Electromagnetic Modeling of Antennas using efficient Time-Domain Integral Equation Techniques + SPICE Circuit Analysis incorporating realistic device models Accurate Prediction of system performance Anatoliy Boryssenko, Dan Schaubert

16 Simulation of Transmit Dipole Antenna Driven with a Nonlinear Pulser Circuit SPICE Engine in Transient Mode Time-Domain MoM EM Engine Anatoliy Boryssenko, Dan Schaubert

17 Highlights of UMass Link Simulation Electromagnetic, circuit and system issues for evaluation and design of antennas, transmitters, receivers. Object-Oriented Technology - flexibility for further advanced numerical simulations, analysis, design and optimizations Frequency/Time Domain Tools supporting co-design and optimization missions for antennas, signal pulses and front-end circuitry Key communication effects - multipath, mobility, cross-polar, EMC & coexistence with shared spectrum systems, FCC regulations, etc. Anatoliy Boryssenko, Dan Schaubert

18 Fundamental Questions about UWB Radiation and Reception 1. What happens when a short pulse is transmitted and received by antennas? 2. How do we define and calculate the link loss for an UWB radio system? 3. What is the optimal generator waveform to maximize receive voltage amplitude, or received energy? 4. How does the choice of transmit and receive antennas affect UWB link performance? 5. What are the fundamental limits for pulse transmission and reception with realistic antennas? 6. (before this MURI research, only Question 1 had been adequately addressed) Dave Pozar

19 UWB Radio Link Loss Analysis Analysis of energy transmission loss between two antennas for transient radiation and reception using three methods: Rigorous electromagnetic analysis (full-wave analysis of antennas and T/R effects difficult, but rigorous) Comparison with narrowband Friis formula (link loss errors up to 60 db, primarily due to impedance mismatch effects) Closed-form approximations for dipoles w/ Gaussian pulses (more accessible than EM analysis, more accurate than Friis formula) Paper to appear: IEEE Transactions on Antennas and Propagation Dave Pozar

20 Comparison of Energy Link Loss for Various Cases Input energy: ( ) 2 R T ( ω) Receive W in = 1 V G ω 2π dω W Z T ( ω)+ Z G ( ω) 2 rec = 1 BW energy: 2π BW ( ) 2 () V L ω Z L* ω dω Friis eq. w/ mismatch: W rec ω W in ω () ( ) = G t( ω)g r ( ω)λ 2 1 Γω ( ) 2 ( 4πr) 2 Link loss: L link = W rec W in Normalized (r =1) Energy Link Loss for Various Antennas and Excitations T/R Antennas Gaussian (rigorous) Monocycle (rigorous) Midband Frequency Midband Friis eq. Midband Friis w/ Z-Mismatch Short Dipoles db 430 MHz db db Resonant Dipoles db 500 MHz db db Lossy Dipoles db 500 MHz db db Dave Pozar

21 Comparison of Closed-Form versus Exact Link Loss (multiplied by r 2 ) for a Gaussian Generator Waveform Electrically short dipoles -65 Dipole length = 1.0 cm Dipole radius = 0.02 cm Link Loss (db) - db rigorous numerical solution closed-form (small R L ) closed-form (large R L ) T = 4.42E-10 s. v G ( t)= V 0 e t 2 /2T Receiver Load Resistance - R L (ohms) Dave Pozar

22 Comparison of Closed-Form versus Exact Link Loss (multiplied by r 2 ) for a Gaussian Monocycle Generator Electrically short dipoles Dipole length = 1.0 cm Dipole radius = 0.02 cm Link Link Loss Loss (db) - db rigorous numerical solution closed-form (small R L ) closed-form (large R L ) T = 4.42E-10 s. v G ( t)= V 0 e t 2 /2T Receiver Load Resistance - R L (ohms) Dave Pozar

23 UWB Optimal Waveform Studies What is the optimal generator voltage waveform to maximize receive voltage amplitude (with constrained input energy)? What is the optimal generator voltage waveform to maximize receive energy in an interval (with constrained input energy)? What is the optimal generator voltage waveform to minimize receive pulse duration (with constrained input energy)? Solutions to these problems, including effects of T/R antennas and loads, have been obtained using variational methods coupled with numerical electromagnetic solutions for various antennas Dave Pozar

24 Receive Voltage Amplitude Optimization diamond dipole, 15 cm long, 10 cm wide GHz, 100 ohm load 1.5E+6 Generator voltage at transmit antenna 2.0E+4 Load voltage at receive antenna 1.0E+6 1.5E+4 Generator Voltage at Transmit Antenna 5.0E+5 Load Voltage at Receive Antenna 1.0E+4 0.0E+0 5.0E+3-5.0E+5 0.0E+0-1.0E+6-5.0E+3-1.5E Normalized Time fot -1.0E Normalized Time f o t generator voltage waveform receive voltage waveform Dave Pozar

25 Receive Energy in Interval Optimization Maximize receive energy in the time interval T to T short dipole, wideband: GHz 1.2E+2 Load Voltage at Receive Antenna 1.2E+2 Load Voltage at Receive Antenna 8.0E+1 8.0E+1 4.0E+1 4.0E+1 Load Voltage at Receive Antenna 0.0E+0 Load Voltage at Receive Antenna 0.0E+0-4.0E+1-4.0E+1-8.0E+1-8.0E+1-1.2E E Normalized Time fo t Normalized Time fo t f o T = 2 f o T = 10 Dave Pozar

26 Receive Energy in Interval Optimization Maximize receive energy in the time interval T to T short dipole, narrowband: GHz 2.5E+3 Load Voltage at Receive Antenna 2.5E+3 Load Voltage at Receive Antenna 2.0E+3 2.0E+3 1.5E+3 1.5E+3 1.0E+3 1.0E+3 5.0E+2 5.0E+2 0.0E+0 0.0E+0-5.0E+2-5.0E+2 Load Voltage at Receive Antenna -1.0E+3-1.0E+3-1.5E+3 Load Voltage at Receive Antenna -1.5E+3-2.0E+3-2.0E+3-2.5E+3-2.5E Normalized Time fo t Normalized Time f o t f o T = 2 f o T = 10 Dave Pozar

27 How Do T/R Antenna Choices Affect UWB Link? Thin dipole, 0.5 cm x 15 cm Diamond dipole, 10 cm x 15 cm Bow-tie dipole, 8 cm x 15 cm Rhombus dipole, 10 cm x 8 cm Dave Pozar

28 Comparison of Receive Voltage Optimizations for Various Antennas Frequency band: 50 MHz 2 GHz Input energy: 1 Joule Antenna R G = R L Link Loss db Peak Voltage f 0 GHz wire dipole, 15 cm long, 0.04 cm diam , flat dipole, 15 cm long, 0.5 cm wide , flat dipole, 15 cm long, 3 cm wide , bow-tie dipole, 15 cm long, 8 cm wide , bow-tie dipole, 15 cm long, 8 cm wide , bow-tie dipole, 15 cm long, 10 cm wide , diamond dipole, 15 cm long, 10 cm wide , diamond dipole, 15 cm long, 10 cm wide , rhombus dipole, 15 cm long, 10 cm wide , Dave Pozar

29 Optimized Receive Voltage Waveforms for Wire and Bow-tie Dipoles 2.0E+4 2.0E+4 Load voltage at receive antenna Load Voltage at Receive Antenna 1.5E+4 1.0E+4 5.0E+3 0.0E+0-5.0E+3-1.0E Normalized Time fo t Load voltage at receive antenna Load Voltage at Receive Antenna 1.5E+4 1.0E+4 5.0E+3 0.0E+0-5.0E+3-1.0E Normalized Time fo t wire dipole, 15 cm long, 0.04 cm diameter (70 Ω) bow-tie dipole, 15 cm long, 8 cm wide (70 Ω) Dave Pozar

30 Optimized Receive Voltage Waveforms for Diamond and Rhombus Dipoles 2.0E+4 2.0E+4 Load voltage at receive antenna Load Voltage at Receive Antenna 1.5E+4 1.0E+4 5.0E+3 0.0E+0-5.0E+3-1.0E Normalized Time f o t Load voltage at receive antenna Load Voltage at Receive Antenna 1.5E+4 1.0E+4 5.0E+3 0.0E+0-5.0E+3-1.0E Normalized Time f o t diamond dipole, 15 cm long, 10 cm wide (100 Ω) rhombus dipole, 15 cm long, 10 cm wide (50 Ω) Dave Pozar

31 UWB Signal Synthesizer Project Computer FPGA Board Receiving system (load) UWB Digital Synthesizer (enable) UWB synthesizer chip High-speed Memory High-speed clock LNA(?) D/A converter Cable Antenna RF Channel Reference Antenna Cable 50 Ω, 2volts, peak-to-peak Concept: digital signal generation to compensate for distortions, fill FCC mask, and control received pulse shape. Current effort: CMOS synthesizer design, D/A parameter trade-offs, openloop and closed-loop algorithms for signal selection. Industrial interest: Agilent, Ando Engineering (Japan), Pico-Second Pulse Labs. Bob Scholtz

32 UWB Signal Synthesizer Project AP9950 and BX4120 UWB Ultra Wideband Signal Generator, Ando Electric Co., Ltd, Yokohama, Japan. Shusaku Shimada demonstrating equipment at the UltRa Lab, July 30 - August 3, Bob Scholtz

33 UWB Signal Synthesizer Project Specification of UWB signal Generator (AP9950 with BX4120) Output waveform : Basically arbitrarily programmable Output amplitude resolution : 4bit (16 levels) Sampling Rate : GHz Internal Clock Resolution: 1kHz, offset : -50 to +50 ppm 9-12GHz External Clock V p-p on 50 ohm/2.92mm Connector Amplitude Error : approx. 5% or 50mV 10mV for Pulse Bi-phase Modulation Clock Jitter: less than 40ps p-p Host interface: 100/10 Base-T Waveform Output: SMA connector Size: 425mm(w), 221mm(h), 500mm(d), 25kg Power Requirement: AC V 50/60Hz Bob Scholtz

34 Antenna-to-Antenna Measurements (TEM to TEM (1) ) n (TEM to diamond dipole (1) ) n Terry Lewis, Bob Scholtz

35 NIST Visit 8/2003 Generator and antenna tests at Bob Johnk s NIST Lab USC TEM half horn and NIST full TEM horn Terry Lewis, Bob Scholtz

36 TEM Horn Experiments Transmitted signal Rx thru USC half horns on ground plane Rx thru half horns on ground plane Rx thru full horns on towers Terry Lewis, Bob Scholtz

37 Design of UWB Transmitter Objective: Design a programmable 3-bit pulse generator with GHz bandwidth in CMOS (0.25um). Challenge: Output bandwidth. Large capacitance at the output from time interleaving. More problematic for large swings (> 1V) and multi-bits. Currently non-existent. SotiriosZogopoulos, Won Namgoong

38 General Approach Distribute output load capacitance using transmission lines. Transmission lines implemented as coplanar micro-strips. Each stage fires at a fixed phase offset and propagation delay after the previous stage. Six 3-bit DACs are interleaved. 50 Ohm Zin = 50 Ohm W S Signal line Stage1 Stage2 Stage3 Stage4 Stage5 Stage6 Antenna Ground lines 50 Ohm Termination Oxide er=4.1 OSC Substarte er=11.9 SotiriosZogopoulos, Won Namgoong

39 UWB Transmitter Layout OSC 2 nd Stage Driver Unit Output Transmission line Program Unit SotiriosZogopoulos, Won Namgoong

40 UWB Transmitter Design Design is currently in fabrication. Layout dimensions are 2.0mm x 3.6mm. Simulation results: Samples transmitted every picoseconds. Voltage swing 1.4V at 80psec. Performance improves with scaling. Less lossy transmission lines using higher metal layers. Faster transistors. SotiriosZogopoulos, Won Namgoong

41 MURI Review Agenda (Morning) 9:00 AM: Opening comments -- Bob Ulman, US ARO 9:05 AM: Introduction to the UWB MURI Research Effort -- Bob Scholtz 9:20 AM: Algorithm and System Architecture Studies Panel: Keith Chugg, Dennis Goeckel, Won Namgoong, Bob Scholtz, David Tse, Dana Porrat, Bob Weaver Topics: UWB Acquisition and Tracking, Channelized UWB Receivers, Alternatives to Selective Rake, UWB Frequency Domain Processing, Capacity Limits of UWB Impulse Radios 10:35 AM: Break 10:45 AM: Antennas and Propagation Topics: Simulation of UWB Antennas and Circuits, UWB Link Budgets, Antennas for UWB, Optimal Waveform Studies, UWB Synthesizer Project Panel: Dan Schaubert, David Pozar, Won Namgoong, Bob Scholtz, Anatoliy Boryssenko 12:00 PM: Lunch Break