Microwave, Sub-mm, and THz Technology for payloads and space (sub)systems Radiometer Physics GmbH (RPG), Germany Harald Czekala RPG Thomas Rose RPG AchimWalber RPG Hugh Gibson RPG Bertrand Thomas RPG Michael Brandt RPG Oleg Cojocari ACST Byron Alderman STFC RAL

RPG Company Profile Microwave, sub-mm, THz Turn-key radiometers, space technology components, design, scientific expertise ■ 4 decades experience ■ 40 employees ■ Radiometers (space) ■ Frontends/Receivers ■ Lab equipment / VNA ■ Components up to THz ■ Design+Manufacturing RPG Microwave Technology SAC, 2011-04-08

RPG Space Heritage MLS/UARS Microwave Limb Sounder (JPL/USA, 1991) (RPG founders working with JPL on Gunn oscillators/multipliers) MHS/FY-3 Microwave Humidity Sounder (CNSA / China, 2008) 150 and 183 GHz Receiver front ends for MHS ODIN (SSC, 2001 until today) 8 Gunn Local Oscilaltors plus fudamental mixers Herschel / HIFI space telescope (ESTEC, 2009) Local Oscillators (480 to 1200 GHz), IF up-converters SMILES (JAXA, 2008 installed on ISS) PLL Gunn LO chain at 360 GHz RPG Microwave Technology SAC, 2011-04-08

RPG Space Heritage (2) SAPHIR+MADRAS / MEGHA-TROPIQUES microwave humidity sounder CNES/ISRO SAPHIR (183 GHz sounder): specially stabilized Gunn resonator (plus contrib. to LO and RF hardware) MADRAS (18.7, 23.8, 36.5, 89, 157 GHz Imager) Gunn LO, DC conditioning, RF networks (M4/M5, 89/157), OMT Components… RPG Microwave Technology SAC, 2011-04-08

Space heritage components Waveguide Components passive Corrugated feed horns Attenuator Coupler RF loads, absorbers RF power splitter Isolator (Y-junction circulator/isolator, Faraday isolator) Waveguide twists Orthomode Transducers (OMT) Optical networks (feedclusters, FSS) Power supply RF components (whisker contacted multipliers) (Gunn oscillators, with PLL / cavity) Planar Multipliers Subharmonic mixers Fundamental mixers MMIC driver amplifiers MMIC low noise amps (LNA) Noise injection (calibration!) Rapid Dicke switching (4-point cal.) PA/QA to delivered hardware RPG Microwave Technology SAC, 2011-04-08

Current involvements ESA TRP (Technology Research Programme) activities ESTEC "Integrated Schottky Structures" (664 GHz Front End)  tripler-mixer FE with integrated circuit design ESTEC "Sub-Millimetre Wave Receiver Front-end" (664 GHz Frontend)  doubler-doubler-mixer with discrete Schottky diodes EU/FP7 "Millimeter-Wave Integrated Diode & Amplifier sources"  over 400 mW (later: 1000) mW @ 100 GHz Qual/Eval activities aiming at TRL-5 expected soon ESA-ESTEC/EUMETSAT METOP Second Generation („Polar Orbiter“) "RPG Sat-B CPI coordination and interface definition support" (OHB) MWI/ICI Receiver Performance & Test Requirements definition (TAS-I) ESA "Cloud and Precipitation Airborne Radiometer" (118 & 664 GHz FE) Proposal ESTEC "243 GHz Direct Detection Radiometers" RPG Microwave Technology SAC, 2011-04-08

Quality Control, tests, procedure, … (PA/QA) RPG offers PA/QA compliant to highest ESA and NASA standards RPG has demonstrated these capabilities RPG advises customers on suitable (tailored) approaches RPG Microwave Technology SAC, 2011-04-08

Space Products (II) Space qualified front ends (China, FY-3): 183 GHz (4 channels) water vapour sounder RPG Microwave Technology SAC, 2011-04-08

Space Products (III) Space qualified front ends (China, FY-3): 90 GHz dual polarized receiver OMT + LNA + (either Direct Detection or Heterodyne) 150 GHz dual polarized receiver: OMT + SHM RPG Microwave Technology SAC, 2011-04-08

Examples: Frontends and sub-systems for Space FIRST/HIFI MADRAS Space qualified local oscillators (Herschel / ESA): 8 local oscillator chains from 480 GHz to 1100 GHz Other space projects: EOS (NASA), ODIN (SSA), FIRST/HIFI, MARFEQ, SAPHIR (CNES), MLS (NASA), FY-3 (China), … RPG Microwave Technology SAC, 2011-04-08

Outline Direct detection (MMIC) for frequencies up to 120 GHz Auto-calibration receivers up to 200 GHz (noise-injection / Dicke sw.) Improvements in mixer and multiplier designs through close cooperation with Schottky diode suppliers Schottky technology from ACST (Germany) Schottky technology from RAL (UK) Subharmonic mixers at 424 GHz and 664 GHz InGaAS mixers with reduction of LO power by 10 dB RPG Microwave Technology SAC, 2011-04-08

Direct Detection Direct detection systems up to 110 GHz (since 8 years now…) LNA mostly based on MMIC supply from IAF Freiburg, Germany At 118 / 150 / 183 GHz and above, sub-harmonic mixers still have better performance (at least with high-quality sub-harmonic mixers) Waveguide filters with high stability and narrow bandwidth (0.25 %) Tsys (with horn, noise-inject., isolator) 20 – 30 GHz 280 K (NF: 2.9) 50 – 60 GHz 550 K (NF: 4.6) 90 GHz 700 K (NF: 5.3) 55 dB Pre-Amplifier Splitter and Filter Section Boosters and Detectors Video Amps, MUX, 16 Bit ADC Noise Injection Coupler 51- 59 GHz 7 Channel Filterbank Receiver 170 mm Corrugated Feedhorn RPG Microwave Technology SAC, 2011-04-08

Direct Detection Receivers Compared to heterodyne systems: Improved noise figure Decreased long term stability (larger 1/f noise with InP MMICs) Much better RFI protection Compact (integrated) design No planar filters, all waveguide Low loss Ortho-Mode Transducer Tsys < 600 K (NF: 4.9) 90 GHz dual-pol (FM) RPG Microwave Technology SAC, 2011-04-08

Direct Detection: MMIC mounting Mounting of all amplifier types Experience in micromachining Bonding and soldering to space standards RPG Microwave Technology SAC, 2011-04-08

Auto-calibration receivers: Noise injection, Dicke Switching Fast calibration with noise diodes and ambient load (gain and Tsys are calibrated) Ambient load / Dicke switch: Isolators driven by switched magnetic field Noise diodes: mounted directly in a waveguide coupling section Applied to direct detection as well as heterodyne receivers Usignal Uambient+noise Uambient Repetition: 5 Hz Duty cycle: 45 % (due to 10 ms switch time) DetectorVoltage Time / s 0.10 0.20 0.15 0.05 RPG Microwave Technology SAC, 2011-04-08

Auto-Calibration Receivers (II) Noise injection calibration up to 200 GHz 7.000 K signal at 183 GHz with stable noise diode (15 dB ENR) Magnetically switched isolators: Dicke switching up to 150 GHz with low insertion loss (≤1.0 dB) Fast switching with low currents (small thermal effects, 100 mA, 0.5 V) ESA-ATPROP 15 / 90 GHz Allan Variance Stability: 4.000 s Less dependent on external calibration targets (LN2)! RPG Microwave Technology SAC, 2011-04-08

Auto-calibration receivers (III): 90+150 GHz system Achieved System Noise Temperatures: (incl. noise injection coupler, Dicke switch, isolator) 90 GHz: 750 K 150 GHz: 1200 K Full internal calibration Isolation > 30 dB Insertion loss @ 90 GHz: 0.7 dB Insertion loss @ 150 GHz: 1.0 dB Allan Variance up to 4000 s RPG Microwave Technology SAC, 2011-04-08

Auto-calibration receivers (IV): 183 GHz system Heterodyne receiver at 183 GHz with 6 channel Filterbank Channel centers in IF: 0.6, 1.5, 2.5, 3.5, 5.0, 7.5 GHz Noise injection for calibration Tsys=1200 K for complete radiometer Tsys=380 to 450 K for mixer Schottky mixer diode by ACST (Germany) Dome-C, Antarctica 3.300m asl, -25 to -80 °C Close to South-Pole Similar System on HAMP (HALO Microwave Package) for HALO research aircraft RPG Microwave Technology SAC, 2011-04-08

Schottky Mixer and Multiplier Improvements Planar technology Discrete Schottky devices Semi-integrated and full integrated structures Two collaborations: STFC/RAL, UK ACST, Germany Mandatory improvements for 800 to 1000 GHz circuit mountings: Reduced Cj0 Reduced Cstr Smaller size ESTEC Contract 22032/08/NL/JA: Sub-Millimeter Wave Receiver Front-End (at 664 GHz) ESTEC Contract 21628/08/NL/GLC: Integrated Schottky Structures (at 664 GHz) RAL Diode Air-bridge Mesa with anode Anode pillar (contact pad) Cathode pillar Back-side ohmic Membrane- substrate Air-bridges Mesas Protection pillars (contact pads) 25μm 50μm ACST Diode Quasi-vertical (QVD) single Diode (SD) Anti-parallel (APD) diode RPG Microwave Technology SAC, 2011-04-08

Schottky Mixer and Multiplier Improvements Planar technology Discrete Schottky devices Semi-integrated and full integrated structures Two collaborations: STFC/RAL, UK ACST, Germany Mandatory improvements for 800 to 1000 GHz circuit mountings: Reduced Cj0 Reduced Cstr Smaller size ESTEC Contract 22032/08/NL/JA: Sub-Millimeter Wave Receiver Front-End (at 664 GHz) ESTEC Contract 21628/08/NL/GLC: Integrated Schottky Structures (at 664 GHz) RAL Diode Air-bridge Mesa with anode Anode pillar (contact pad) Cathode pillar Back-side ohmic Membrane- substrate Air-bridges Mesas Protection pillars (contact pads) 25μm 50μm ACST Diode Quasi-vertical (QVD) single Diode (SD) Anti-parallel (APD) diode RPG Microwave Technology SAC, 2011-04-08

Improved Diodes: Vector Network Analyzer Products 50 – 75 GHz 60 – 90 GHz 75 – 110 GHz 90 – 140 GHz 110 – 170 GHz 140 – 220 GHz 220 – 325 GHz 325 – 500 GHz (500 – 750 GHz) OEM Network Analyzer Frequency Extenders for Rohde & Schwarz Courtesy of Rohde & Schwarz RPG Microwave Technology SAC, 2011-04-08

Improved Diodes: Tx/Rx Products Transmit / Receive Systems: 90 GHz 183 GHz 220 GHz 324 GHz 502 GHz 640 GHz 870 GHz For compact ranges (antenna measurement facilities, phase + amplitude) Multipixel Array 220 – 325 GHz RPG Microwave Technology SAC, 2011-04-08

Improved Diodes: RPG sub-harmonic mixers Art.-No. RF Range [GHz] DSB-Noise Temperature Conversion Gain (DSB) IF-Band- width Required LO Power Waveguide LO RF SHM118 104-132 500 K -5 dB > 16GHz 6 dBm WR15 WR8 SHM137 110-165 -6 dB > 20 GHz 4-7 dBm WR12 WR6.5 SHM150 134-167 450 K > 16 GHz 2 dBm SHM183 167-200 430 K -4 / -5 dB 4 dBm WR10 WR5.1 SHM220 185-230 > 18 GHz SHM280 265-295 700 K -7 dB WR3.4 SHM300 275-330 900 K SHM340 310-360 1000 K -6 / -7 dB WR2.8 SHM424 400-440 1100 K -7/ -8 dB 7 dBm WR4.3 WR2.2 SHM664 644-680 1600 K -8 dB WR1.5 RPG Microwave Technology SAC, 2011-04-08

Receiver technology – 183 GHz example 183 GHz feeds and sub-harmonic mixers for ALMA-WVR Best 183 GHz receivers available Built in larger numbers Noise-injection calibration @183 (RPG only manufacturer world wide) All ALMA water vapor radiometers equipped with RPG mixers and feeds RPG Microwave Technology SAC, 2011-04-08

Improved Diodes: RPG sub-harmonic mixers Art.-No. RF Range [GHz] DSB-Noise Temperature Conversion Gain (DSB) IF-Band- width Required LO Power Waveguide LO RF SHM118 104-132 500 K -5 dB > 16GHz 6 dBm WR15 WR8 SHM137 110-165 -6 dB > 20 GHz 4-7 dBm WR12 WR6.5 SHM150 134-167 450 K > 16 GHz 2 dBm SHM183 167-200 430 K -4 / -5 dB 4 dBm WR10 WR5.1 SHM220 185-230 > 18 GHz SHM280 265-295 700 K -7 dB WR3.4 SHM300 275-330 900 K SHM340 310-360 1000 K -6 / -7 dB WR2.8 SHM424 400-440 1100 K -7/ -8 dB 7 dBm WR4.3 WR2.2 SHM664 644-680 1600 K -8 dB WR1.5 RPG Microwave Technology SAC, 2011-04-08

Sub-Harmonic Mixer: 424 GHz LO Power: 5 mW Tmix=800 to 1200 K Tsys=1800 K (Feed, SHM, IF Amp, Detection) Conversion= –7 dB RPG Microwave Technology SAC, 2011-04-08

Sub-Harmonic Mixer: 664 GHz LO Power: 3 mW Tmix ≈ 1600 K Conversion: –7.5 to –9.5 dB RPG Microwave Technology SAC, 2011-04-08

Further Schottky Diode Optimization: InGaAs Only at ACST: InGaAs Diode InGaAs built-in voltage (barrier height) significantly lower than GaAs (0.2eV compared to 0.8eV) Reduced LO power required for SHM at 183 GHz: 0.34 mW (10 dB less!) 183 GHz InGaAs mixer with 0.2 / 0.25 / 0.34 mW LO-power 183 GHz InGaAs GaAs Tmix 700 K 500 K 430 K Conv. Loss –6.6 dB –5.5 dB –4.2 dB LO Power 0.34 mW 3.0 mW 2.2 mW RPG Microwave Technology SAC, 2011-04-08

Technical Study – SWI for EJSM Europa Jupiter System Mission (EJSM, Laplace), NASA / ESA Orbiter: Jupiter Ganymede (JGO) Instrument: Submillimetre-Wave (SWI) Situation distance to Jupiter: 106 km (15 RJ) primary: 300 mm frequency bands: 530 – 590 1090 – 1266 scanning: 2-axis: +/- 4° (limb) 1-axis: +/- 60° (moons) science requirement: 10 m/s (winds in limb) angular resolution: < 2 // pointing knowledge: 11.5 // SWI - JGO – EJSM ESA / NASA Mission zum Jupiter Zwei Frequenzbänder, 2-Achsen scanning (along-track und cross track) Hohe Pointing Anforderungen, Gewicht <10kG, hohe Strahlenbelastung nahe Jupiter Machbarkeitsstudie von RPG beinhaltet: Mechanische Struktur, 600 GHz Empfänger Perfomance, Thermales Design 4° 65°

Technical Study – SWI for EJSM: Principal Setup Incoming microwave radiation secondary primary SWI-telescope Instrument unterteilt sich in drei Teile: Teleskopstruktur Optisches Compartment CTS und Elektronik in der Vault des Satelliten receivers and optics compartment platform common shielded vault electr. + synth. CTS spectro. other instr. RPG Microwave Technology SAC, 2011-04-08

Technical Study – SWI for EJSM Mechanical Design secondary primary Zwei-Achsen Scanmechanismus Primary drehbar für Along-track Scanning +/-65° Gesamtes Teleskop Kippbar für Cross-track Scanning +/- 4° along-track scanning optics compartment pusher rotation axis cross-track scanning RPG Microwave Technology SAC, 2011-04-08

classical enclosed housing good radiation shielding receiver feeds hot load 1200 GHz receiver chain IF-LNAs telescope beam Optik und Empfänger geschirmt in Gehäuse untergebracht. Verlustarme Optik, minimaler Platzbedarf, hoher Strahlungsschutz. Gesamtes Design von RPG calibration flip mirror beam splitter Optics Compartment: 600 GHz receiver chain low-loss Gaussian Telescope beam path small overall size (170 x 290 mm2) thermally stabilized mixer, PA, hot load classical enclosed housing good radiation shielding

Technical Study – SWI for EJSM: Mass Budget Surface primary mirror (Mg) 750 g actuators (all) 680 g receivers (both) 280 g telescope structure 1370 g optics plate 1130 g sum: 4210 g Teleskop mit Optik nur 4210g Komponenten in der Vault 2800g -> gesamtes Instrument nur 7000g Vault spectrometers (CTS) 1500 g electronics 1000 g synthesizers 300 g common shielded vault other instr. sum: 2800 g Electr. + Synth CTS Spectro. total: 7010 g

Conclusion / Summary Direct detection with superior performance (over heterodyne) up to 120 GHz (until better MMIC LNA technology becomes available) Auto-calibration receivers up to 200 GHz Cooperation with Schottky diode manufacturers for improved devices Development of improved mixers and multipliers up to 900 GHz, leading to: VNA extenders covering all bands to 500 GHz (and soon even further) Transmit/Receive systems up to 900 GHz Excellent sub-harmonic mixers Outstanding performance at 183 GHz, 424 GHz, 664 GHz Further steps: ■ Substrate Transfer ■ High-Power varactors (driver stages for THz) ■ Film Diode Technology ■ Continuing reduction of capacities and size Results partly supported by: ESTEC Contract 22032/08/NL/JA: Sub-Millimeter Wave Receiver Front-End @ 664 GHz ESTEC Contract 21628/08/NL/GLC: Integrated Schottky Structures @ 664 GHz Thank you! RPG Microwave Technology SAC, 2011-04-08

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RPG ESA/ESTEC/EU current activities Ongoing ESA and Space application activities: ESTEC “Integrated Schottky Structures” (664 GHz FE, ICI) ESTEC “Sub-Millimetre Wave Receiver Front-end” (664 GHz FE, ICI) EU/FP7 “Millimeter-Wave Integrated Diode & Amplifier sources” (100 GHz) ESTEC/EUMETSAT Metop Second Generation: „RPG Sat-B CPI coordination and interface definition support” (OHB) MWI/ICI Receiver Performance & Test Requirements definition (TAS-I) ESA “Cloud and Precipitation Airborne Radiometer” (118 & 664 GHz FE) Proposal ESTEC„243 GHz Direct Detection Radiometers“ MHS from the FY-3 satellite / China RPG Microwave Technology SAC, 2011-04-08

ESTEC & RPG Dreamteam RPG Microwave Technology SAC, 2011-04-08 Schedule Now T 0 T0 +7 T0+14 T0+22 T0+50? Phase 0 (MetOp SG Req.) A1 A2 B1 B2 (PDR) C (CDR) D (AI&T) Technology Development Technology Pre-Evaluation Eval & LAT ICI AI&T 2 Development contracts (ongoing) Qualified Instuments ESTEC ESTEC ESTEC ESTEC Pre Evaluation Results LAT Results Instrument Design Component Requirements Design & Test Results RPG Consultancy RPG AI & T RPG Pre-Eval. RPG Eval & LAT RPG ? AI & T Component Requirements ITT: Development & sample man. Qualified Components ACST Diode -manufacturing Diodes ACST Diode -manufacturing Diodes RAL/Teratec Diode -manufacturing Diodes RAL/Teratec Diode -manufacturing Diodes RPG Microwave Technology SAC, 2011-04-08

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