modernizing rf and microwave - nxp...
TRANSCRIPT
External Use
TM
Modernizing RF and Microwave
Power Applications
Solid State Heating Solutions
FTF-IND-F0408
A P R . 2 0 1 4
Dan Viza | RF Product Manager
TM
External Use 1
Session Introduction
• Evolution of RF Power Solutions:
− Solid state RF power is evolving to a level of performance suitable for
effective use as an alternative to traditional magnetrons in a range of
heating applications from cooking food to plastic welding
• Enabling New and Differentiated Heating & Cooking Solutions:
− Appliance and commercial kitchen OEM’s can begin creating
differentiated solutions and new end product types enabled by RF power
which enable closed loop operation
TM
External Use 2
Agenda
• Freescale RF Power Introduction
• Traditional RF Power Devices
• Key Differences Between Magnetron and Solid State
• Implications For Microwave Cooking Application
• Summary
• Contacts For More Information
TM
External Use 3
RF Power: In Your Daily Life
Amplify RF Signals and Deliver:
• High Power
• High Linearity
• High Efficiency
Portfolio Range:
• From 2.8 MHz to 4.0 GHz
• From 0.1W to 1.25kW
Healthcare Cooking Cellular
Air Traffic Control FM Radio
Professional
Mobile Radio
Wafer Plasma Etch
Freescale RF Power
Products
TM
External Use 4
Freescale Leads Industry In RF Power Innovation
BILLIONS Watts/Year Delivered
Modernization of RF Power
Innovative Application of RF Power
TM
External Use 5
Traditional RF Power Devices
• Vacuum Electron Devices (VED’s)
can be divided into several types:
− Magnetrons
− Power Grid Device (Triode, Tetrode)
− Traveling Wave tubes (TWTs)
− Klystrons
− Crossed-field Amplifiers (CFAs)
− Gyrotrons
• Covering frequencies from DC to
95GHz and from 10s of watts to
megawatts.
• Size: 4x3 36x36x120
• Weight: 2# 5600#
• Scary voltages: 1KW ~ 3KV min
• 5s 5m warmup
Klystrons
Magnetrons
Traveling Wave Tubes
TM
External Use 6
Modernizing RF Power Heating: Magnetron To Solid State
Magnetron
• 4,000V supply voltage
• 500 – 1000 hours lifetime,
degrades over time
• Bulky, heavy
• Simple On-off control
RF Transistor
• 28-50V supply voltage
• Up to 20 years lifetime, no
degradation
• Small, low mass
• High resolution control
TM
External Use 7
Microwave Oven Background & Fundamentals
• Microwave oven commercially
introduced 1947 (Raytheon)
• Dielectric heating due to dipole
rotation
• 2.4GHz typical (ISM)
− 915MHz also used
• Magnetron microwave energy
source
− Self oscillating device
− Filament warm up time required
− Relatively broadband
Turntable
Waveguide Stirrer
Magnetron
High Voltage
Transformer (Hidden)
• Stirrer, turntable used to
“distribute” energy
• System efficiency > 56%;
degrades over time
TM
External Use 8
Solid State Cooking: How Is It Different? More Than A Magnetron Replacement
Turntable
Waveguide Stirrer
Magnetron
Solid State Oven Magnetron Oven
• Selective cooking
• Versatile: complex food
combinations
• Improved consistency
• Reduced time
• “Floods” and heats cavity
• Crude On/Off control
• Electro-mech BOM
• Degrades over time
Solid State
RF Power
Closed loop, controlled RF power
• Direct energy to load
• Reflected energy received
• Absorbed energy analyzed
• Multiple sources
TM
External Use 9
Power Control
• Fine control at low levels
− Power can be set to any level from
less than 1% to 100%
− Enables effective heating of low mass
objects
• Magnetron uses PWM with ~10
second minimum on time
− Magnetron filament requires initial
heat up time
− Best in Class magnetron can vary to
60% then goes to PWM
• Precise cooking, warming,
defrosting, thawing through control
of power
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
0% 50% 100%
Required Power
De
live
red
Po
we
r
Magnetron
Solid State
TM
External Use 10
Phase Control Location Optimization
• Detecting “load” location and shifting phase in multi-feed system
− Optimize energy to load location
• Output is coherent, allowing phase and amplitude control of multiple sources
− Enable selective combining of the energy
• Analogous to laser vs flood light
• Reduces random ‘hot spots’
− Lab tests show as many as 5 hot spot locations Position
Antenna Antenna
Phase
Control
TM
External Use 11
Frequency Control – Managing IoT Interference
Conventional microwave oven emission
covers virtually complete Wifi spectrum (all
channels simultaneously) Detection and frequency shifting enable
elimination of smart home device
interference
Conventional MWO Emission Solid State MWO Emission
Vs. WiFi Router
Frequency
Po
we
r
WiFi Signal
SS MWO Signal MWO Signal
TM
External Use 12
Electro-Mechanical Simplification
• Reduced electro-mechanical
component BOM
− Stirrer
− Waveguide
− Turntable
• Reduced Weight
− Magnetron ~1.6 lbs
− High voltage power supply
• Enabling design flexibility
− Antenna location flexibility
− Flush mounted antenna
1 in3 vs. 31.5 in3
Turntable
Waveguide Stirrer
Magnetron
2”
1” 1/2”
Deep
3”
3”
3 1/2”
Deep
Antenna
TM
External Use 13
Solid State Cooking & Heating Advantages
Feature Benefit
High Resolution Control
• Precise cooking/heating
• Highly efficient
• Higher quality nutrition
• Faster meal preparation
• Versatile food preparation
• Low noise
• IoT interference management
Durability • Consistent heating parameters over lifetime
• Reduced maintenance
Reduced Size & Weight • Form factor design flexibility
• Lower logistics costs
TM
External Use 14
Freescale Microwave Solutions
TM
External Use 16
Microwave Heating Device Roadmap
Available Now 2013 2014
75W
250W
500W
MHT2000N
MHT1001H
MHT1000H 140W @ 2.45 GHz, 45% eff.
25W @ 2.45 GHz IC
190W @ 2.45GHz, 45% eff.
Production
Proposal
Planning
Execution
28-32 V LDMOS
300W @ 2.45GHz, 65% eff.
MHT2001N
50 V LDMOS
Plastic
2015
175W @ 900MHz IC, 70% 2nd stage eff.
250W @ 2.45GHz, 55% eff.
48V GaN
350-300W @ 900-1300MHz, 55% eff.
MHT2002N
50W @ 2.45 GHz IC
MHT1007H
RF & Microwave Heating Products
1: Discrete
2: IC
3. System
H: ceramic
N: plastic
MHT1002N
Right edge
= launch
MHT1003N
MHT1004N
15W driver @ 2.4 GHz
MHT1006N
MHT2003N
50W@ 2.4 GHz; >60% Eff
TM
External Use 18
RFPT-MHT3003 Eval Board250W Power Amplifier Configuration
RFPT-MHT3003
High Gain PA
SMA
N-F
I O
F R
MHT2000N MHT1003N
Log Amp
Current Shunt
Amp
Log Amp
Current Shunt
Amp
2 Wire Temp
sensor
50mV at Imax Shunt
Temp1
Temp 2
RF Det 2
RF Det 3
I1
I2
V1
Temp sensor
Vg1
Vg2 Vg3
Log Amp
RF Det1
Input r dividert
Coupler
Log Amp
LT5534 or
AD8314 RF Det 4
28-32V
Supply
TM
External Use 19
Freescale Microwave Oven Reference Designs
All reference designs include:
• Integrated MCU
• Kinetis MCU + Signal Generator + Receive
Path
• High performance microwave power amplification
• Closed loop features
• Real time delivered power measurement
• Mismatch detection
• Temperature and voltage sensing
250W @ 2.45GHz
Single antenna or feed interface
500W @ 2.45GHz with Power
Boost
Single antenna or feed interface
500W @ 2.45GHz
Dual antenna or feed interface
Components Eval Boards
Ref Designs
TM
External Use 15
Summary
Modernizing Microwave Ovens Solid state RF power technology proving capable of delivering differentiated perfomance
High Resolution Control Enabling new functions and applications
Improved Size, Weight, and Mechanical Complexity Opening the door for design freedom and durability
Freescale Leading The Evolution With components, eval boards, tools, reference designs
TM
© 2014 Freescale Semiconductor, Inc. | External Use
www.Freescale.com