UNIT V - PPT-MIC S1-5 mcrowave integarted circuits.pdf

measurement techniques

1. UNIT V
MIC MESUREMENT TECHNIQUES
Session
S1-S5

2. Microwave Integrated Circuits
Microchip for Microwave frequencies.
It can incorporate innumerable
components of different types, (passive
and active) into a small chip to form a
complete microwave subsystem.
Size, weight and cost are reduced much.

3. Types of Microwave circuits
Discrete circuit:
➢Packageddiodes/transistorsmountedincoaxialandwaveguide
assemblies.
➢Devicescanusuallyberemovedfromtheassemblyand
replaced.
HybridMIC:
➢Diodes/transistors,resonators,capacitors,circulatorsetc.,are
fabricatedseparatelyonmostappropriatematerialandthen
mountedintothemicrostripcircuitandconnectedwithbondwires
MMIC:
➢Diodes/transistors,resistors,capacitors,microstripetc.,are
fabricatedsimultaneously,includingtheirinterconnections,in
semiconductorchip

4. Typical spiral inductor and interdigitated capacitor
Loop inductor
High impedance transmission line inductor
Figure: Microstripelements used in MMIC

5. MMIC
ThesubstrateofanMMICmustbea
semiconductormaterialtoaccommodatethe
fabricationofactivedevicesanddevices
consisting,severallayersofmetal,dielectric
andresistivefilms.
Potentially,theMMICcanbemadeatlowcost
becausethemanuallabourinthefabricationof
hybridMICsiseliminatedandthatasingle
wafercancontainalargenumberofcircuits,
allofwhichcanbeprocessedandfabricated
simultaneously.

6. Monolithic Microwave Integrated Circuit (MMIC)

7. PhotographofamonolithicintegratedX-bandpoweramplifier.Thiscircuit
useseightheterojunctionbipolartransistorswithpowerdividers/combiners
attheinputandoutputtoproduce5watts.

8. Courtesy : Internet

9. Advantages and Disadvantages of MMICs
Advantages:
1-Minimal mismatches and minimal signal delay.
2-There are no wire bond reliability problems.
3-Up to thousands of devices can be fabricated at one time into a
single MMIC.
4-It is the least expensive approach when large quantities are to
be fabricated.
Disadvantages:
1-Performance compromised, since the optimal materials cannot
be used for each circuit element.
2-Power capability is lower because good heat transfer materials
cannot be used
3-Trimming adjustments are difficult or impossible.
4-Unfavorable device-to-chip area ratio in the semiconductor
material.
5-Tooling is prohibitively expensive for small quantities of MMIC.

10. Materials used for MIC
➢Substrate materials
➢sapphire, alumina, ferrite/garnet, silicon, RT/duroid, quartz, GaAs,
Inp, etc.,
➢Conductor materials
➢copper, gold, silver, aluminum, etc.
➢Dielectric films
➢SiO, SiO
2,…etc
➢Resistive films
➢Nichrome(cNiCr), tantalum (Ta)

11. Commonly used substrate materials
1. Organic PCBs (Printed Circuit Boards)
➢FR4
1) Low cost, rigid structure, and multi-layer capability.
2) Applications for operation frequency below a few GHz.
fopLoss 
2. Plastic substrate
➢RT/Duroid
1) Low loss and good for RF applications.
2) Board has a wide selected range for permittivity. e.g. RT/Duroid5870 with 
r
=2.33, RT/Duroid5880 with 
r=2.2, and RT/Duroid6010 with 
r=10.2.
3) Board is soft leading to less precise dimensional control.
1) This is suitable for experimental circuits operating below a few GHz and
array antennas operating up to and beyond 20 GHz.

12. 3. Alumina
1) Good for operation frequency up to 40 GHz.
2) Metallic patterns can be implemented on ceramic substrate using thin-film or
thick-film technology.
3) Passive components of extremely small volume can be implemented because the
ceramic substrate can be stacked in many tens of layers or more, e.g. low
temperature co-fired ceramic (LTCC).
4) Good thermal conductivity.
5) Alumina purity below 85% should result in high conductor and dielectric losses
and poor reproducibility.
4. Quartz
1) Production circuits for millimetricwave applications from tens of GHz up to
perhaps 300 GHz, and suitable for use in finlineand image line MIC structures.
2) Lower permittivity of property allows larger distributed circuit elements to be
incorporated.

13. 5. Sapphire
➢The most expensive substrate with following advantages:
1) Transparent feature is useful for accurately registering chip
devices.
2) Fairly high permittivity (
r=10.1~10.3), reproducible ( all pieces
are essentially identical in dielectric properties), and thermal
conductivity (about 30% higher than the best alumina).
3) Low power loss.
➢Disadvantages:
1) Relatively high cost.
2) Substrate area is limited (usually little more than 25 mm
square).
3) Dielectric anisotropy poses some additional circuit design
problems.

14. 6. Beryllia(BeO) and AluminiumNitride (AlN):
➢Ceramic substrate.
➢Excellent thermal conductivity –high power applications.
➢Dangerous to handle –Its dust is toxic and must not be
machined.
7. GaAs:
➢Suitable for MMICs. LownoiseMESFET, Power MESFET,
Schottkydiodes are fabricated on GaAs.

16. Conductor Materials
Properties:
1.High conductivity
2.High coefficient of thermal expansion
3.Low resistance at RF/microwaves
4.Good adhesion to the substrate
5.Good etch ability and solder ability
6.Easy to deposit or electroplate
Example:
HMIC: Cr/Au, Pd/Au, Ta/Au
MMIC: Cr/Au, Ti/Pd/Au, Ti/Pt/Au

17. Properties of Conductors :

18. Dielectric Films
1.Reproducibility
2.High breakdown voltage
3.Low loss tangent
4.Ability to Process without developing
pinholes.
➢Capacitors
➢Protective layers for active devices
➢Insulating layers for passive circuits

19. Properties of Dielectrics :

20. Resistive Films
1.Good stability
2.Low Temperature Coefficient of Resistance
(TCR)
3.Sheet resistivity (10-2000 /square)
Terminations
Attenuators
Bias Networks
Examples:
Cr, NiCr, Ta, Cr-Sio, Ti

21. Properties of Resistive Films :

22. Properties of Various Manufacturing Technology

23. •Power amplifiers
•Mixers
•Transmit/ receive module
•Cellular telephones
•Direct broadcast satellite
•Radar transmission and detection
•Automobile collision avoidance system
Applications of MMIC

28. A multi-chip module (MCM) is an electronic package consisting of multiple
integrated circuits (ICs) assembled into a single device. An MCM works as a single
component and is capable of handling an entire function. The various components
of a MCM are mounted on a substrate, and the bare dies of the substrate are
connected to the surface via wire bonding, tape bonding or flip-chip bonding. The
module can be encapsulated by a plastic molding and is mounted on the printed
circuit board. MCMs offer better performance and can reduce the size of a device
considerably.
An MCM offers a packaging efficiency of more than 30%. Some of its advantages are
as follows:
Improved performance as the length of the interconnection between dies is reduced
Lower power supply inductance
Lower capacitance loading
Less crosstalk
Lower off-chip driver power
Reduced size
Reduced time to market
Low-cost silicon sweep
Improved reliability
Increased flexibility as it helps in the integration of different semiconductor
technologies
MCM Technology

29. Simplified design and reduced complexity related to the packaging of several
components into a single device.
MCMs can be manufactured using substrate technology, die attach and bonding
technology, and encapsulation technology.
MCMs are classified based on the technology used to create the substrate. The
different types of MCM are as follows:
MCM-L: Laminated MCM
MCM-D: Deposited MCM
MCM-C: Ceramic substrate MCM
Some examples of MCM technology include the IBM Bubble memory MCMs, Intel
Pentium Pro, Pentium D Presler, Xeon Dempsey and Clovertown, Sony memory
sticks and similar devices.
A new development called chip-stack MCMs allows dies with identical pinoutsto be
stacked in a vertical configuration, allowing for greater miniaturization, making them
suitable for use in personal digital assistants and cell phones.
MCMs are commonly used in the following devices: RF wireless modules, power
amplifiers, high-power communication devices, servers, high-density single-module
computers, wearables, LED packages, portable electronics and space avionics.