Improvements in Microwave and Sub-mm Frontend Technology for Use up to 900GHz Radiometer Physics GmbH (RPG), Germany Harald Czekala RPG Thomas RoseRPG.

Improvements in Microwave and Sub-mm Frontend Technology for Use up to 900GHz

Radiometer Physics GmbH (RPG), Germany

Harald Czekala RPGThomas Rose RPGAchimWalber RPGHugh Gibson RPGOleg Cojocari ACSTByron Alderman STFC RAL

Microwave Technology and Techniques Workshop ESTEC, 2010-05-11 2

RPG Company Profile

Microwave, sub-mm, THzTurn-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


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


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 %)

Splitter and Filter Section

Boosters and Detectors

Video Amps,MUX, 16 Bit ADC

55 dB Pre-Amplifier

Noise InjectionCoupler

51- 59 GHz 7 ChannelFilterbank Receiver

Corrugated Feedhorn

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)

170 mm


Direct Detection Receivers

90 GHz dual-pol (FM)

Low loss Ortho-Mode TransducerTsys < 600 K (NF: 4.9)

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


Direct Detection: MMIC mounting

• Mounting of all amplifier types

• Experience in micromachining

• Bonding and soldering to space standards


Usignal

Uambient+noise

Uambient

Usignal

Repetition: 5 HzDuty cycle: 45 % (due to 10 ms switch time)

Det

ecto

rVo

ltag

e

Time / s0.10 0.20 0.15 0.05

Auto-calibration receivers: Noise injection, Dicke Switching

Fast calibration with noise diodes and ambient load(gain and Tsys are calibrated)

Ambient load / Dicke switch:Isolatorsdriven by switchedmagnetic field

Noise diodes:mounted directlyin a waveguidecoupling section

Applied to direct detectionas well as heterodynereceivers


Auto-Calibration Receivers (II)

Allan Variance Stability: 4.000 sLess dependent on external calibration targets (LN2)!

• 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


Achieved System Noise Temperatures:(incl. noise injection coupler, Dicke switch, isolator)

90 GHz: 750 K 150 GHz: 1200 K

Allan Varianceup to 4000 s

Full internal calibrationIsolation > 30 dBInsertion loss @ 90 GHz: 0.7 dBInsertion loss @ 150 GHz: 1.0 dB

Auto-calibration receivers (III): 90+150 GHz system


Heterodyne receiver at 183 GHzwith 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 diodeby ACST (Germany)

Auto-calibration receivers (IV): 183 GHz system

Similar System on HAMP

(HALO Microwave Package)

for HALO research aircraft

Dome-C, Antarctica

3.300m asl, -25 to -80 °C

Close to South-Pole


Schottky Mixer and Multiplier Improvements• Planar technology• Discrete Schottky devices• Semi-integrated and full integrated structures

Two collaborations:■ STFC/RAL, UK■ ACST, Germany

Mandatory improvementsfor 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)

Air-bridge

Mesa with anode

Anode pillar(contact pad)

Cathode pillar(contact pad)

Back-side ohmic

Membrane-substrate

Air-bridges Mesas

Protection pillars(contact pads)

Back-side ohmic

Membrane-substrate

25μm

50μm

Quasi-vertical (QVD)

single Diode (SD)

Anti-parallel (APD) diode

RAL Diode

ACST Diode


Improved Diodes: Vector Network Analyzer Products

OEM Network Analyzer Frequency Extendersfor Rohde & Schwarz

50 – 75 GHz60 – 90 GHz

75 – 110 GHz90 – 140 GHz

110 – 170 GHz140 – 220 GHz220 – 325 GHz 325 – 500 GHz(500 – 750 GHz)

Courtesy of Rohde & Schwarz


Improved Diodes: Tx/Rx Products

Transmit / Receive Systems:90 GHz 183 GHz220 GHz 324 GHz502 GHz 640 GHz 870 GHzFor compact ranges (antenna measurement facilities, phase + amplitude)

Multipixel Array220 – 325 GHz


Improved Diodes: RPG sub-harmonic mixers

Art.-No. RF Range[GHz]

DSB-NoiseTemperature

ConversionGain (DSB)

IF-Band-width

Required LO Power

WaveguideLO RF

SHM118 104-132 500 K -5 dB > 16GHz 6 dBm WR15 WR8

SHM137 110-165 500 K -6 dB > 20 GHz 4-7 dBm WR12 WR6.5

SHM150 134-167 450 K -6 dB > 16 GHz 2 dBm WR12 WR6.5

SHM183 167-200 430 K -4 / -5 dB > 16 GHz 4 dBm WR10 WR5.1


SHM280 265-295 700 K -7 dB > 18 GHz 4-7 dBm WR6.5 WR3.4


SHM340 310-360 1000 K -6 / -7 dB > 16 GHz 4-7 dBm WR6.5 WR2.8

SHM424 400-440 1100 K -7/ -8 dB > 16 GHz 7 dBm WR4.3 WR2.2



Receiver technology – 183 GHz example

• 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

183 GHz feeds and sub-harmonicmixers for ALMA-WVR


Improved Diodes: RPG sub-harmonic mixers

Art.-No. RF Range[GHz]

DSB-NoiseTemperature

ConversionGain (DSB)

IF-Band-width

Required LO Power

WaveguideLO RF

SHM118 104-132 500 K -5 dB > 16GHz 6 dBm WR15 WR8


SHM150 134-167 450 K -6 dB > 16 GHz 2 dBm WR12 WR6.5

SHM183 167-200 430 K -4 / -5 dB > 16 GHz 4 dBm WR10 WR5.1




SHM340 310-360 1000 K -6 / -7 dB > 16 GHz 4-7 dBm WR6.5 WR2.8

SHM424 400-440 1100 K -7/ -8 dB > 16 GHz 7 dBm WR4.3 WR2.2



Sub-Harmonic Mixer: 424 GHz

Tsys=1800 K

(Feed, SHM, IF Amp, Detection)

Tmix=800 to 1200 K

Conversion= –7 dB

LO Power: 5 mW


Sub-Harmonic Mixer: 664 GHz LO Power: 3 mW

Conversion: –7.5 to –9.5 dB

Tmix ≈ 1600 K


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


Examples: Frontends and sub-systems for Space

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), …

FIRST/HIFI FIRST/HIFI


Space Products (II)

Space qualified front ends (China, FY-3):

183 GHz (4 channels) water vapour sounder


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


• 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 GHzESTEC Contract 21628/08/NL/GLC: Integrated Schottky Structures @ 664 GHz

Thank you!

Conclusion / Summary

Improvements in Microwave and Sub-mm Frontend Technology for Use up to 900GHz Radiometer Physics GmbH (RPG), Germany Harald Czekala RPG Thomas RoseRPG.

Documents

microwave technology

noise injection calibration

techniques workshop

noiseinjection dicke

f noise

frontend technology

direct detection receivers

db slide