Transcript Slide 1

Compact Integrated Receivers Using
Custom and Commercial MMIC Technology
Matt Morgan
9/7/2006
Compact Integrated Receivers
1. critical for focal plane arrays
 beam spacing
 field of view
2. lower mass
 more efficient cryogenics
 tighter temperature control
 reduced mechanical load
3. fewer connectors and cables
 greater reliability
 reduced VSWR effects
 reduced gain slopes
 fewer entry points for RFI
MMIC Modules are More Compact, Lightweight
and Manufacturable than Conventional Assemblies
Assembly of Individually
Packaged Components
Multi-Chip Module
Many MMICs available Commercially
Most things below 50 GHz are available off-the-shelf for less than $50
Exceptions include:
 balanced port configurations
 non-standard impedance
 some wide IF-Band mixers
Some things in the 50-100 GHz range can be found in commercial product
listings, but
 sparse frequency coverage
 usually narrow-band, targeted for specific applications
(communication and radar bands, etc.)
 some exotic functions not supported (compound switches, etc.)
Finally, there is a large pool of proven custom designs to draw from,
designed by NRAO and our collaborators (JPL, ATA, universities,
foundry IRAD designs, etc.)
Some Examples: W-Band Signal Source
2.5 cm
Some Examples: Compact Water Vapor Radiometer
All Commercial MMICs!
Some Examples: ALMA Active Multiplier Chain
Some Examples: DSN Array Ka-Band Downconverter
Working Toward an All-MMIC Receiver
1. Once a design is set, MMIC components and assemblies can be massproduced with exceptional repeatability
 especially in the cm-wave range, where most MMICs are
commercially available – chips are screened by the manufacturer
and their specs guaranteed.
 module assembly is insensitive to small variations – bondwires are
used for 50  interconnects, not for tuning!
2. Repairs are relatively easy to diagnose and repair
 because of the inherent uniformity in performance, device failure is
usually apparent from the DC bias alone.
 when it isn't, the chips are cheap enough to simply replace them one
at a time until the culprit is found.
It is therefore reasonable to think about implementing even very sophisticated
front-ends in a single module using all MMIC technology.
 no internal connectors!
 no internal cables!
 only 1 block to machine
 small, lightweight, manufacturable
Shall we take integration a step further:
Receiver-on-a-Chip?
I would say no...
 LNAs, mixers, and multipliers have all been demonstrated on common
semiconductor technologies, but with compromised performance – better
to pick the right MMIC process for the right chip
 even if it works, the yield is too low on III-V semiconductors for large-scale
integration
 a lot of expensive wafer real estate is wasted on passives
 can no longer take advantage of commercial components – have to design
it all from scratch
 no opportunity for chip reuse
 Microwave substrates are thin! A large, floppy chip would be too hard to
handle and mount without damaging it.
Could We Put the Whole Receiver in One
Module and Cool Everything?
Not if it is a heterodyne receiver, because
 LO generation dissipates too much power for cryogenics
 IF components are usually Silicon, which will not function cold
However, special-purpose direct detection receivers could occupy
a single cold module
 even more compact
 better sensitivity
 better temperature stability
 better component lifetime
Another Problem: Why are those bias boards so big?
Because we put a lot on them!
 linear regulators
 potentiometers for tuning and gain
control
 digital logic for configuration switching
and channel selection
 Op-Amps for gate servo loops and
monitor points
 IF circuitry
It makes for a user-friendly module, but
if we're serious about compactness,
particularly for focal plane arrays, then we
must find a way to trim this part down.
Option #1: Develop Common Bias Blocks in Die Form
or Integrated SMT Packages
Two external resistors
set the desired drain
voltage and current.
Probably very expensive!
(unless we buy millions of them)
Not suitable for cooling if done
in Silicon.
Option #2: Limit DC inputs to analog bias voltages
Put nothing in the block except
basic EMI and over-voltage
protection.
All current control, monitoring,
and tuning functions can be
implemented in a central M&C
unit (more efficiently, in fact...)
Option #2: continued...
With all monitor functions in one place, some parts can be shared.
What About LNAs?
MMIC LNAs
Pros
Cons
MIC LNAs
 more compact
 easier to integrate in large
multi-function modules
 easy to replicate
 module assembly can be
done commercially
 higher-Q passive components
 allows pre-selection of active
devices for optimum
performance
 larger development cost
 difficult to transfer assembly
"know-how" to commercial
manufacturers.
A "Nearly Monolithic" LNA
Discrete stage
MMIC stage
Maybe we can compromise between optimum performance and large-scale
manufacturability by using a hand-picked first-stage discrete device followed
by a MMIC.
Case Study: Ka-Band All-MMIC Receiver
COLD MODULE
WARM MODULE
2-4 GHz
26-40 GHz
2-4 GHz
26-40 GHz
BPF
BPF
TRW
HCA4200P
Velocium
ALH369
Triquint
TGL-4203
Velocium
ALH369
Mimix BB
XM1001
Sirenza
SBB-5089
Anaren
11306-3
24-36 GHz
12-18 GHz
6-9 GHz
BPF
x2
BPF
Mimix BB
XX1000
x2
Hittite
HMC205
Triquint
TGL-4203
Avago
HMMC-5618
2-4 GHz
26-40 GHz
2-4 GHz
26-40 GHz
BPF
BPF
TRW
HCA4200P
Velocium
ALH369
Triquint
TGL-4203
Velocium
ALH369
Mimix BB
XM1001
Anaren
11306-3
Sirenza
SBB-5089
Calculated Performance:
 noise temperature = 10 K
 gain = 60 dB
 P1dB = -45 dBm (input)
 LO = 2 mW (6-9 GHz)
 power dissipation = 150 mW (cold part), 3.5 W (warm part)
All-MMIC Cold Receiver Module
IF outputs
IF hybrids
MMICs
RF inputs
LO input (underneath)
All-MMIC Cold Receiver Module
The size of a well-designed MMIC module is typically
dominated by connectors and waveguide flanges.
MMIC-Based Cold Receiver Assembly
Cooled Focal Plane Array
OMT
MMIC
Module
Bias/M&C
IF
LO IF
Backup slides follow
If the entire receiver is cooled anyway, should we consider
using superconducting passive elements (couplers, filters, etc)?
I don't think so
 excellent LNA performance can be achieved at ~20K, but a good
microwave superconductor would force you to much lower
temperatures (~5K)
 not really a commercial process – your passive elements
could be more expensive than the MMICs!
 you lose the ability to test it at room temperature
 not much to gain anyway? – superconductors are not lossless
at high frequency, and cooled copper may be competitive if it is
reasonably pure