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Radio Frequency EngineeringLecture #1 Passives - Extra
Stepan Lucyszynステファン・ルシズィン インペリアル・カレッジ・ロンドン准教授
Lecture #1
Passives – Extra
Radio Frequency EngineeringLecture #1 Passives - Extra
Stepan Lucyszynステファン・ルシズィン インペリアル・カレッジ・ロンドン准教授
RF Inductors
Printed Spiral
Inductor
Straight narrow wire or PCB track
Coil on former
with slug tunerCoil
Radio Frequency EngineeringLecture #1 Passives - Extra
Stepan Lucyszynステファン・ルシズィン インペリアル・カレッジ・ロンドン准教授
10 MHz – 40 GHz conical inductor, ~ 2.2 mm long
Full of EM absorber
VERY
LOSSY!!
Radio Frequency EngineeringLecture #1 Passives - Extra
Stepan Lucyszynステファン・ルシズィン インペリアル・カレッジ・ロンドン准教授
RF Capacitors
4p7
Ceramic
Polystyrene
Polyester
TrimmerSurface mount
Single layer chip
Radio Frequency EngineeringLecture #1 Passives - Extra
Stepan Lucyszynステファン・ルシズィン インペリアル・カレッジ・ロンドン准教授
“Opti-CapTM Broadband SMD Capacitor DC to Light”Dielectric Laboratories Inc.
Ultra-Broadband DC Blocking Capacitors
Small capacitor in parallel with large capacitor,
Plus resistive damping of resonances
Radio Frequency EngineeringLecture #1 Passives - Extra
Stepan Lucyszynステファン・ルシズィン インペリアル・カレッジ・ロンドン准教授
RF Resistors
Radio Frequency EngineeringLecture #1 Passives - Extra
Stepan Lucyszynステファン・ルシズィン インペリアル・カレッジ・ロンドン准教授
Grounding methods: (a) through-substrate via-holes, (b) wrap-around grounding and (c) bond-wires
MIM capacitor
Metalised lower ground plane
GaAs substrate
Via hole Metalised lower ground plane
GaAs substrate
MIM capacitor
Gold-plated chip carrier
GaAs substrate
(a) (b)
(c)
Radio Frequency EngineeringLecture #1 Passives - Extra
Stepan Lucyszynステファン・ルシズィン インペリアル・カレッジ・ロンドン准教授
Through-substrate vias are difficult to realise with brittle substrates (e.g. silicon, GaAs, alumina, etc.) and have reliability implications. Up to ~20 GHz, they can be modelled with a simple series R-L circuit.
Wrap-around grounds have reduced inductance. However, they require an edge metalisation process and they still impose severe restrictions on the topology of the circuit.
Bond wires have relatively high inductance (e.g. ~1 nH/mm with 25 m diameter wires). Therefore, multiple wires are needed, which must be kept as short as possible. Moreover, they impose severe restrictions on the topology of the circuit, since they have to be located near the edge of the MIC. This type of grounding can be modelled with a fringe capacitance in parallel with the inductor.
Radio Frequency EngineeringLecture #1 Passives - Extra
Stepan Lucyszynステファン・ルシズィン インペリアル・カレッジ・ロンドン准教授
l
Lj
l
R
l
Z HFHF
Rwidth
llengthL oo
HF
2,
,
2
mmmLR
mmpHL
mm
HFHF
ooHF
o
o
ooo
/119
/192/10252
10
2
368.21014.22
1
2
6
3
9
Simplified Bond Wire Modelling
Given a gold bond wire, having a bulk DC resistivity of 22.14 n.m and 25 m diameter, calculate the skin depth, the internal HF inductance per millimetre and HF resistance per millimetre at 3.6 GHz.
Ignoring a factor that accounts for the shape (length over diameter) of the wire!
a factor of ~ 40 too low
about right
Radio Frequency EngineeringLecture #1 Passives - Extra
Stepan Lucyszynステファン・ルシズィン インペリアル・カレッジ・ロンドン准教授
Radio Frequency EngineeringLecture #1 Passives - Extra
Stepan Lucyszynステファン・ルシズィン インペリアル・カレッジ・ロンドン准教授
Radio Frequency EngineeringLecture #1 Passives - Extra
Stepan Lucyszynステファン・ルシズィン インペリアル・カレッジ・ロンドン准教授
© 2001 Amkor Technology, Inc.
Radio Frequency EngineeringLecture #1 Passives - Extra
Stepan Lucyszynステファン・ルシズィン インペリアル・カレッジ・ロンドン准教授
Bare-chip device and typical parasitics
Microstrip
Hole through to ground, with gold plated chip carrier insert
g d s
End effect capacitance of the microstrip ~ 0.02 pF
Bond pads ~ 0.04 pF each
Bond wires ~ 0.8 nH per mm length
Radio Frequency EngineeringLecture #1 Passives - Extra
Stepan Lucyszynステファン・ルシズィン インペリアル・カレッジ・ロンドン准教授
Interconnect stack in the Intel 130nm P860 technology
Radio Frequency EngineeringLecture #1 Passives - Extra
Stepan Lucyszynステファン・ルシズィン インペリアル・カレッジ・ロンドン准教授
There are three quite distinct circuit design techniques, the choice of which largely depends on the operating frequency of the circuit
There is inevitably some overlap of each approach's useful frequency range of application, and the techniques may often be blended together in the same design
· “all-transistor” techniques
· lumped-element techniques
· distributed-element techniques
ALL-TRANSISTOR
LUMPED ELEMENT
MICROSTRIP
0 20 40 60 80 100 GHz
MICROMACHINED STRUCTURES
CPW
Circuit Design Techniques
Radio Frequency EngineeringLecture #1 Passives - Extra
Stepan Lucyszynステファン・ルシズィン インペリアル・カレッジ・ロンドン准教授
All-transistor Techniques
· circuits tend to use small device peripheries so that the resulting small input and output capacitances do not unduly affect performance (e.g. operational amplifiers)
· usable up to at least 5 GHz, and such high frequency of operation is achieved largely because of the low capacitance, rather than the use of microwave design techniques
· the design of these circuits at GHz frequencies requires tremendous design skill and experience. This is available in the silicon industry, but generally not in GaAs industry
· the major advantage of active techniques is their high packing density, leading to competitively priced products, but at the expense of increased DC power consumption
Radio Frequency EngineeringLecture #1 Passives - Extra
Stepan Lucyszynステファン・ルシズィン インペリアル・カレッジ・ロンドン准教授
'all-transistor' circuit: 2 GHz MMIC band-pass filter (employing 3 active inductors)
Radio Frequency EngineeringLecture #1 Passives - Extra
Stepan Lucyszynステファン・ルシズィン インペリアル・カレッジ・ロンドン准教授
'all-transistor' active inductors (equivalent Q-factor of 15,000)
Radio Frequency EngineeringLecture #1 Passives - Extra
Stepan Lucyszynステファン・ルシズィン インペリアル・カレッジ・ロンドン准教授
2 GHz MMIC active band-pass filter frequency performance
Radio Frequency EngineeringLecture #1 Passives - Extra
Stepan Lucyszynステファン・ルシズィン インペリアル・カレッジ・ロンドン准教授
The advantages of active filters are:1. small size and mass2. low cost in mass production3. high selectivity4. easy integration with amplifiers, mixers, oscillators5. potential for electronic tuning.
Drawbacks associated with active techniques:1. poor noise figure2. non-linearity3. danger of oscillation4. complex bias circuitry and significant DC power5. sensitivity to fabrication tolerances6. environmental sensitivity
Radio Frequency EngineeringLecture #1 Passives - Extra
Stepan Lucyszynステファン・ルシズィン インペリアル・カレッジ・ロンドン准教授
Pre-driver and Receiver Applications
Radio Frequency EngineeringLecture #1 Passives - Extra
Stepan Lucyszynステファン・ルシズィン インペリアル・カレッジ・ロンドン准教授
SiGe HBT 80 Gb/s Distributed Amplifier, chip size = 1.3 x 1.7 mm2
O. Wohlgemuth et al. (Lucent), EuMC 2003
Radio Frequency EngineeringLecture #1 Passives - Extra
Stepan Lucyszynステファン・ルシズィン インペリアル・カレッジ・ロンドン准教授
Lumped-element Techniques
· for higher operating frequencies, the transistor’s input and output capacitances must be accounted for
· lumped-element matching networks (using spiral inductors and overlay capacitors) provide the best solution at frequencies below 20 GHz.
Lumped-element circuit: 1 to 2 GHz MMIC feedback amplifier (employing L-C
components)
VDVG
INPUT
OUTPUT
Radio Frequency EngineeringLecture #1 Passives - Extra
Stepan Lucyszynステファン・ルシズィン インペリアル・カレッジ・ロンドン准教授
A spiral transformer Marchand balun (0.7 x 1.5 mm2)
Port 2
Port 1
Port 3
Radio Frequency EngineeringLecture #1 Passives - Extra
Stepan Lucyszynステファン・ルシズィン インペリアル・カレッジ・ロンドン准教授
Lumped-distributed equivalent of a quarter-wave transmission line
sin4/Z
Zo 4/
cos
ZC
CC
Z 0 , l
Radio Frequency EngineeringLecture #1 Passives - Extra
Stepan Lucyszynステファン・ルシズィン インペリアル・カレッジ・ロンドン准教授
Lumped-distributed branch-line coupler
CC
CC
Input Direct
CoupledIsolated
Radio Frequency EngineeringLecture #1 Passives - Extra
Stepan Lucyszynステファン・ルシズィン インペリアル・カレッジ・ロンドン准教授
The lumped element equivalent of a quarter-wave transmission line
L =Z o
w
C C =Z ow1
Radio Frequency EngineeringLecture #1 Passives - Extra
Stepan Lucyszynステファン・ルシズィン インペリアル・カレッジ・ロンドン准教授
Lumped-element Wilkinson power divider
C
C
2C
L
L
2ZoIN
OUT
OUT
Radio Frequency EngineeringLecture #1 Passives - Extra
Stepan Lucyszynステファン・ルシズィン インペリアル・カレッジ・ロンドン准教授
Lumped-element branch-line coupler
L1
C
C
L1
L2
C
C
L2
Input Direct
CoupledIsolated