Millimeter-Wave Test and Measurement from 2000-2020

Dr. Eric W. Bryerton

Virginia Diodes, Inc.

Charlottesville, VA USA

Outline

• ALMA Receiver (LO) Development– Wideband tunerless frequency multipliers up to 1 THz

• Wideband Frequency Multipliers– Add amplifiers and filters -> Sub-mm Signal Generator Extender

• Wideband Schottky Diode Heterodyne Mixers– Add LO amplifiers, etc. -> Sub-mm Spectrum Analyzer Extender– Millimeter-wave Spectrum Analyzer Applications

• Signal Generator Extender + Spectrum Analyzer Extender = Sub-mm Vector Network Analyzer

• Cubesat Sub-mm Radiometers• Conclusion

Frequency [GHz]

ALMA (Atacama Large Millimeter Array)Receiver Development (~1998-2007)

• 66 antennas (12m and 7m dishes)• 10 receiver bands from 30-950 GHz• 2 heterodyne receivers for each band

– HEMT LNA up to 115 GHz, SIS mixer above 115 GHz• Requires local oscillators up to 950 GHz (~20-100 uW)

ALMA Receivers

4

Warm Cartridge Assembly with LO YIG Tuned Oscillator and

Driver Stage (up to ~120 GHz)

Morgan, 2005 CSIC Digest

Cryogenic Front End

4K Stage with SIS Mixers

Schottky Diode Multipliers on 77K Stage

Driver contains integrated multi-chip

modules taking ~12-24 GHz YTO output to 65-

122 GHz output

ALMA Receiver Cryostat

ALMA Science

• ALMA image of the young star HL Tau and its protoplanetary disk.

• Credit: ALMA (NRAO/ESO/NAOJ); C. Brogan, B. Saxton (NRAO/AUI/NSF)

Nature Astronomy, 14-Sep-2020

• PH3 (phosphine) 1-0 rotational transition at 1.123 mm (267.1 GHz)

Imaging of Protoplanetary Disk Detection of Phosphine on Venus

polar

mid-latitude

equatorial

• Development of broadband tunerlessfrequency multipliers was a key enabling technology for ALMA

• Extension to full waveguide band (for tunerless multiplers and then mixers) was a key enabling technology for fullband test and measurement frequency extension modules up to 1.1 THz

From ALMA to Laboratory THz Test and Measurement

THz Signal Generation Using Schottky Diodes

• Use the nonlinearity of the Schottky diode to generate harmonics of a lower frequency signal– Use either nonlinear variable capacitance (varactor:

narrowband, high-efficiency) or resistance (varistor: wideband, low-efficiency)

FINFOUT=N*FIN

Planar Diode Fabrication Technology

• Diodes fabricated at VDI– Small captive cleanroom

for the fabrication of devices

• Schottky Flip Chip Diodes– Low parasitics– Flip chips as small as

100x50x20 um

• Integration of Diode with Coupling Circuitry– Operation to higher

frequencies (>3 THz)

9

Standardized Waveguide Interfaces

• VDI uses a waveguide interface compatible with the IEEE standard– Standard was released in 2016– IEEE P1785 – “Rectangular Metallic

Waveguides and Their Interfaces for Frequencies of 110 GHz and Above”

• Allows for compatibility between different manufacturers

• VDI is currently using waveguide interfaces up to 1.5 THz– Details on the VDI website

10

P1785.2 Interface shown for WM-164 Tripler

Amplified Multiplier Chains (AMC)

• Combination of amplifiers and multipliers

• Nearly all the power in a single tone

– Spectral purity achieved using filtering and balanced designs

11

S

w Nw

x2 xM

Pow

er

Frequency

w Nw

Amp MultiplierSynthesizer

Signal Generator Extenders (SGX)

• Signal Generator extenders (SGX) standard up to 1.1 THz. – Tunerless, instantaneous sweeping over > 40% bandwidth

• AM modulation and Power Control capability– Voltage controlled– Modulation can also be controlled by drive synthesizer

12.7cm x 7.6 m x 3.8cm

ALMA Band 9

Signal Generator Extenders (SGXs)

• Low Drive – for use with <20 GHz sources

• High Drive – improved harmonic performance

13

Schottky Diode Detectors

• Biased or Zero-bias diodes available

• Waveguide-based detectors– High Sensitivity

• 3000 V/W @ 100 GHz• 300 V/W @ 1.5 THz

– Bandwidth limited to 40-50%

• Quasi-optical Detector– Bandwidth 100 GHz to > 1

THz– Responsivity 500 V/W typ.

• Sub-ns Response time

WR-3.4ZBD Quasi-optical DetectorDC

Output

sigPV det

RF

Input

14

Heterodyne Detection Using Schottky Diodes

• Balanced antiparallel diode configuration– Allows for 2nd harmonic operation with

excellent sensitivity– LO ~ RF / 2

• Diodes mounted in split-block metal housing

• Noise Figure ~ 8 dB (SSB) at D-band

15

RF

LO

IF=RF-2*LO

0

500

1000

1500

2000

100 120 140 160 180

Tmix

(K

) (D

SB)

Frequency (GHz)

Measured Performance of WR-6.5SHM

Note: This is not a classic high harmonic mixer…

Subharmonic Mixer with LO Drive Chain

16

Pow

er

Frequency

• Clean LO generated to drive mixer – single tone – Filtering and balanced

designs to allow 2nd

harmonic operation

• Mixing between high frequency LO and RF– IF = |RF – 2*LO|

• Excellent sensitivity

S x2 x3 XLO/N LO RF

IF=|RF – 2*LO|

LO/NLO

Test & Measurement: Spectrum Analyzers

• Sophisticated instrument to analyze microwave signals– Spectral purity– Phase noise– Communication Signal

Demodulation– …

• A core microwave test capability– Along with sources and

vector network analyzers

• Can be extended to THz using Schottky mixers

17

Spectrum Analyzer Extenders (SAX)

• Spectrum Analyzer extenders (SAX) standard up to 1.1 THz. – Tunerless, instantaneous sweeping over > 40%

bandwidth– IF Bandwidth up to 40 GHz– DANL 150 dBm/Hz to 750 GHz

• 135 dBm/Hz to 1.1 THz

Regulatory Testing of First 5G Handset

19

Automotive Emissions Application

• Testing up to ~330GHz

N9029AV03 220 – 330 GHz

N9029AV05 140 – 220 GHz

N9029AV08 90 – 140 GHz

N9029AV12 60 – 90 GHz

N9029AH19 40/50-60

GHz @ RF port2

N9029AH12 60-90 GHz

N9029AH05 140-220 GHz

N9029AH03 220-330 GHzLO/IF

LO/IF

LO/IF

LO/IF

N9029AH08 90-140 GHz

U1816C USB

Coaxial

Switch

N9041B UXA

Signal Analyzer

1.85mm(f) to 1.85mm(f) 2m Cable

LO/IF

DC-40/50 GHz @ RF

port1

SWC-19VF-E1

Block Upconversion

IF

LORF

fIF (GHz)

P(d

Bm

)

100 5

• Preserves signal modulation• UpConversion is DSB• LSB can be filtered• Useful as source for Rx

development• Channel characterization

21

fRF (GHz)

P(d

Bm

)

LO*N + 100 LO*NLO*N – 10

SAX-UP for Comm Applications

1/16/2021 22

BPF AmpxN

LO InputHigh Freq.

IF Input

SignalGenerator

SignalGenerator

Block Up-Conversion

• Can be used to upconvert or downconvert wide band modulated signals• The double side band nature of the device makes filtering necessary• VDI has developed a set of waveguide filters and amplifiers to be used for

these applications

Bandpass Filters for Comm Links

1/16/2021 23

P/N Waveguide Size Pass Band (GHz) -40dB Points (GHz)

WR12BPF59.5-61.6 WR12 59.5-61.5 59.1 & 62.8

WR12BPF71-76 WR12 71-76 70.3 & 77.7

WR12BPF81-86 WR12 81-86 79.2 & 89.3

WR6.5BPF152-162 WR6.5 152-162 147.5 & 166.75

• Low pass band insertion loss (<1dB)• High out of band rejection (~100dB)• Sharp band edges• Custom filters can be produced

-120

-100

-80

-60

-40

-20

0

65 70 75 80 85 90 95

dB

Frequency(GHz)

VDIE-BandFiltersMeasuredPerformance

Amplifiers for Comm Links

1/16/2021 24

• Can be used to overcome conversion and transmission losses

• Waveguide solution• Receives DC bias from SAX-UP

SAX: Communications Example

• Simulated radio for signal with 2 GHz modulation bandwidth– Mixer IF centered at 5 GHz

• Allows separation between upper and lower sidebands for filtering

25

THz Vector Network Analyzer Extenders

26

• Calibrated 2-port s-parameter measurements up to 1.5 THz

• Ease of use for probe stations and antenna test chambers

• Integrated components (mixers, multipliers and amplifiers)

Cubesat Sub-Millimeter Radiometers

• Cubesats have significant mass, volume, and power constraints

– Typically 3U (10cm x 10cm x 30cm) or 6U (10cm x 20cm x 30cm)

• Sub-millimeter local oscillators are large DC power consumer

– Minimize multiplication factor after final power amplifier

– Use high-efficiency varactor multipliers

• High level of integration to reduce mass and volume

TROPICS Cubesat Constellation

• 180-206 GHz, 4-channel radiometer• Noise Diode + 3 LNAs + Hybrids +

Filters + Detectors• 2.0” x 1.25” x 0.5”

IceCube: 874-GHz Submillimeter Wave Radiometer for Cloud Ice Remote Sensing

NASA Goddard Space Flight Center

D. L. Wu (P.I.)

30

• Launched as secondary payload on ISS resupply mission on April 18, 2017

• Deployed from ISS on May 17, 2017– Along with 16 other CubeSats– Second set of 17 CubeSats deployed a few days later

IceCube Deployed from ISS

Cubesat Polarimetric Ice Cloud Submillimeter (684 GHz) Sensor

31

LO Input

“Normal” IF

“Ortho” IF

OMT + Twist

• Development of broadband tunerless frequency multipliers, required for ALMA, was a key enabling technology for full waveguide band test and measurement frequency extension modules up to 1.1 THz

• Mixers can be used to upconvert very wideband modulated signals to millimeter-waves

• Schottky diode multiplier and mixer technology still being used and developed for new sub-millimeter wave science instruments

Conclusions

Thank You!