Transcript Typically Realizable Components in MICs by Ipshita Saha

TYPICALLY REALIZABLE COMPONENTS IN MICS
Passive components
•
•
•
•
•
•
•
•
•
•
•
Low pass,high pass
Band pass,band stop with medium to large bandwidths
Directional couplers
Power splitters
Power combiners
Circulators,isolators(with ferrite substrates)
Attenuators
Resonators
Transformer circuits
Branches
Antennas
•
•
•
•
•
•
•
•
•
•
•
Demodulators
Receiver and up-converter mixers
Field effect and bipolar transistor amplifiers
Transistor-power amplifiers
Frequency multipliers
PIN-diode switches
PIN-diode phase shifters
Limiters
Modulators
Oscillators and transistors,Gunn and IMPATT diodes
Controllable attenuators
•
•
•
•
High frequency receiver components
Transmitters(small-signal and pulsed transmitter)
Phase controlled antenna modules(phased array antennas)
Doppler radar modules
Semiconductor Circuits
Subsystems
FUNCTIONAL COMPONENTS OF A MIC ( FROM A VIEWPOINT OF A CIRCUIT DEVELOPER )
Electrical functional units
•
•
•
•
•
•
•
•
Straight-line striplines(e.g. microstrip,coplanar lines)
Stripline discontinuities(e.g. branches,bends,open and short circuits)
Concentrated reactive components:capacitors,inductors
Circuit terminations
High frequency resistances(e.g. attenuators)
Resistors in bias supplies for semiconductors
Semi conductors:diodes,transistors
Special components(e.g. circulators,dielectric,resonators,stripline,antennas)
Mechanical functional units
•
•
•
Housing
High frequency connections
Dc connections
STRUCTURAL COMPONENTS OF A MIC OF A THIN-FILM HYBRID TYPE( AS SEEN FROM THE
TECHNOLOGICAL STANDPOINT )
Layered Circuit
•
•
•
•
•
•
Substrate
Integrated elements:
Conductor structure
Resistor structure(with or without alignment)
(Laminated capacitors)
Hybrid elements:
Capacitors(e.g. ceramic chips and beam lead capacitors)
Semiconductors:diodes,transistors(with or without packaging)
Trimmer capacitors and resistors
Circulators(inserted ferrite disks)
Dielectric resonators(HDK ceramic blocks)
Semiflexible miniature coaxial lines
Connector sections(wires,bands)
Substrate openings(holes for through-contacts,notches)
Plastic coverings and protective covers for sensitive hybrid elements
Packaging
•
•
•
Individual housing ( hermetically sealed or not)
High frequency connectors,substrate to substrate connections
Dc connections(lead through capacitors)
COMPARISON WITH THIN-FILM HYBRID CIRCUIT
•
•
•
•
•
•
•
•
•
As compared with Al2O3 ceramic thin-film circuits GaAs MMICs have the following properties:
Higher upper limiting frequencies and wider possible bandwidths due to low reactive interconnections;
Better reproducibility of performance due to the lack of wire and band connections in the circuit;
Higher packing density,smaller substrate sizes,higher miniaturization,higher number of circuits(up to 100 per large
substrate) in volume production;
Cheaper for larger production runs;
No adjustment possible;
Slightly smaller choice of semiconductor components(e.g. no IMPATTs) but includes the possibility of new circuit
concepts(active transistor matching,active mixers);
Investment in equipment necessary;
Harder to develop circuits,so computer aided design(CAD) is essential.
CRITERIA FOR THE CHOICE OF SUBSTRATE MATERIAL IN THIN FILM USES
Required property
Reason
Mechanical carrier for the circuit
•
•
•
•
Mechanical stability(“robustness”)(e.g. against
breakage)
Maintenance of shape(no cold flow)
High thermal conductivity
•
Long term stability against environment(temperature
changes,high and low temperature
storage,dampness,industrial waste gases)
Thermal expansion similar to that of metals
•
Small dimensional variations
•
•
•
•
•
•
Mechanical loads upon equipment due to shock and
vibration during use
Stable package mounting
Heat removal from components(e.g. power transistors)
Reliability of the circuit
Reliable packaging(e.g. soldering) over entire operating
temperature range
Precise fit in housing to avoid parasitic reactance at
connector
Wave conducting medium
•
•
•
•
•
•
•
•
High er(10-20)
Er homogeneity
Small variation in er from sample to sample
Minimum variation of er with temperature
Low dielectric loss(tan(delta e) < 0.001)at microwave
frequencies
No water absorption
High specific resistance p>10^10ohms cm
Small variations in thickness(within a substrate and
from sample to sample)
•
•
•
•
•
•
•
•
Size reduction(high wavelength reduction factor)
Homogenous circuit parameters
Reproducible production qualities
Low temperature dependence of filters and resonators
Low loss circuits,high Q
Maintenance of circuit operation in damp air
Low loss circuits
Reproducibility of circuit parameters
•
High electrical insulation strength
•
Circuits for high powers
Technological medium
•
Stability at high temperatures(1000-2000 degree C)
•
•
•
Chemical reactance
Flat surface,low cambering
•
•
For thin film and thick film technologies and
soldering(not for simple etching technologies)
For photo etching techniques
For high structural accuracy when using photomasks
•
Smooth surface(indentation depth sigmaeff < 0.5 micro
m,core size < 1 micro m)
Easily workable(drilling and separating)
Maintenance of shape under pressure
Surface without defects(e.g. pin holes)
Thermal expansion coefficient similar to that of
conductor material
•
For high adhesion of thin film conductors
•
•
•
•
Through contacts,cutting,and preparation
For thermo compression and ultra sonic bonding
For thin film capacitors
Adhesion of conductors
•
•
•
•
•
Low production costs
Low production costs
Low production costs
Low production costs
Economical production
•
•
•
•
Commercial and Manufacturing
criteria
•
•
•
•
•
Low cost
Easy to store
Safe to machine
Generally available
Delivering in large plates
SYSTEM OF INTEGRATED MICS
Circuit Technology
Substrate Type
Conductor Type
•Lumped element MICs
•Distributed MICs (stripline MICs)
•Plastics(e.g. PTFE)
•Ceramic
•Ferrite
•Sapphire
•Semiconductor
•Microstrip
•Triplate
•Suspended substrate
•Finline(mm waves)
•Dielectrics waveguide(mm waves)
•Mixed circuits
•(e.g. microstrip,slotline,coplanar lines)
Technology
Degree of integration
•Simple photolithography(in general,for
plastic substrate)
•Thin film technology
•Only conductor
•Conductor +R
•Conductor +R +C
•Thick film technology
•Combined thin film and semi
conductor growth technology
•Semiconductor technology(monolithic
MICs)
•Hybrid circuits
•Conductor integrated
•Conductor +R integrated
•Conductor +R+C integrated
•Semiconductor or sapphire
•Monolithic MICs