References

RF circuits design Grzegorz Beziuk

RF characteristics of lumped passive and active elements

References [1] Tietze U., Schenk C., Electronic circuits : handbook for design and application, Springer 2008 [2] Golio M., RF and microwave passive and active technologies in: RF and Microwave handbook, 2008, CRC Press Taylor and Francis Group [3] Vishay, 50 GHz Thin Film Microwave Resistors, Products Data Sheet, Vishay 2009, (www.vishay.com) [4] AVX RF, AVX RF/Microwave products version 8.1, Products Data Sheet, (www.avxrf.com) [5] Panasonic, Chip inductors, Products Data Sheet, (http://www.panasonic.com/industrial/electronic-components/inductive-products/chipinductors.aspx) [6] Vishay semicondutors, BFR 93 - Silicon NPN Planar RF Transistor, Product Data Sheet, 2000, Vishay. [7] NXP Semiconductors, BFU725F/N1 NPN wideband silicon germanium RF transistor, Product Data Sheet, 2009, NXP Semiconductors (www.nxp.com)

References [8] Infineon Technologies, BFP 620 NPN Silicon Germanium RF Transistor, Product Data Sheet, 2004, Infineon Technologies (http//www.infineon.com/silicondiscretes) [9] ON Semiconductors, MMBFU310LT1G JFET Transistor N−Channel, Product Data Sheet, 2009, ON Semiconductors (www.onsemi.com) [10] EPCOS, SAW Components, Data Sheet R 850, 2002, EPCOS, (www.epcos.com) [11] Fabian Wai Lee Kung, RF/Microwave Circuit Design, 2008, Multimedia University, (open source lectures: http://pesona.mmu.edu.my/~wlkung/ADS/ads.htm) [12] Microsemi, KV1911A – KV1991A VARACTOR DIODES UHF Microwave Super-Hyperabrupt Junction, 2007, Products Data Sheet, Microsemi [13] Hawlett Packard, Surface mount microwave Schottky detector diodes HSMS 2850, HSMS 2860 series, Technical data, Hawlett Packard [14] Maccom Technology Solutions, MA4AGBLP912 AlGaAs Beamlead PIN Diode, Products Data Sheet, Maccom Technology Solutions [15] Vishay Telefunken, BF966S N–Channel Dual Gate MOS-Fieldeffect Tetrode, Depletion Mode, Product Data Sheet, 1999, Vishay Telefunken [16] Murata Manufacturing, SAW resonators, Products Data Sheet, 2001, Murata Manufacturing

Resistors

Equivalent circuits SMD resistor: a) for low frequencies range, b) for high frequencies

Resistors Z R ( jω ) =

[(

)

R + j ω LR − C R R 2 − ω 3 L2R C R

(1 − ω L C )

2

2

R

R

R < LR / C R

Capacitive properties:

R > LR / C R

ΓR ( jω ) =

2 R

+ω C R

Inductive properties:

Reflection factor:

2

]

2

Z R ( jω ) − Z 0 Z R ( jω ) + Z 0

Resistors Impedance of SMD resistors od the size 1206 with LR = 3nH, CR = 0.2pF

* Taken from „Electronic circuits : handbook for design and application” Tietze U., Schenk C. [1]

Resistors

Typical very high frequency performance electrical model The external reactance (Lc and CG) depends on the PCB material, the layout and assembly technology.

Resistors

Impedance as a function of frequency for a chip resistor N termination (wraparound) * Taken from „50 GHz Thin Film Microwave Resistors”, Products Data Sheet, Vishay [3]

Resistors

Impedance as a function of frequency for a chip resistor (F and P terminations) * Taken from „50 GHz Thin Film Microwave Resistors”, Products Data Sheet, Vishay [3]

Capacitors

Equivalent circuits SMD capacitor: a) for low frequencies range, b) for high frequencies

Capacitors Impedance of capacitor:

Resonant frequency:

Quality factor (QF):

Z C (s) =

1 + sCRC + s 2 LC C sC

f res =

1 2π LC C

Qres =

1 RC

LC C

Im{Z C ( j 2πf )} QC ( f ) = Re{Z C ( j 2πf )}

f < f res / 4

≈

1 2πfCRC

Capacitors Magnitude of impedance for SMD capacitors of size 1206 with RC = 0.2Ω, LC = 3nH


Capacitors

Example of parameters of the high frequency capacitors

* Taken from „AVX RF/Microwave products version 8.1”, Products Data Sheet, AVX RF [4]

Chip Inductors

Equivalent circuits SMD inductors: a) for low frequencies range, b) for high frequencies

Chip Inductors Parasitic resistance

RL ( f ) = k RL

Resistive losses coefficient

(skin effect!!!)

f

k RL ≈ k L L

(

For 1206 size inductor:

k L ≈ 600Ω /

For 1812 size inductor:

k L ≈ 1200Ω /

)

Hz ⋅ H

(

Hz ⋅ H

)

k RL ≈ 20Ω / Hz (L )

0.7

For inductors larger than 1812 size, and L>10µH :

Chip Inductors Resonant frequency:

f res = Qres =

1 2π LC L 2π k RL

4

L3 CL 1 2 Qres

Phase resonant frequency

f resph ≈ f res 1 −

Magnitude resonant frequency

f res max ≈ f res 1 −

Quality factor (QF):

QL ( f ) =

(an impedance of inductor has a real value)

1 4 2Qres

Im{Z L ( j 2πf )} Re{Z L ( j 2πf )}

f < f res / 4

≈

2πfL 2πL = RL ( f ) k RL

f

Chip Inductors Magnitudes of impedance and inductor quality for SMD inductors of size 1206 with k L = 1200Ω / Hz ⋅ H and CL=0.2pF

(

)


Chip Inductors

* Taken from „Chip inductors”, Panasonic Products Data Sheet, [5]

Chip Inductors

* Taken from „Chip inductors”, Panasonic Products Data Sheet, [5]

Chokes Choke is a kind of inductor. Chokes are used below 2 GHz, but there are some chokes applications extends to tens of GHz. Chokes: - for high frequency are high impedance elements - for low frequency and direct current have very little loss Chockes are use in the bias circuits of active elements. Because the choke is an inductors with ferrite core, for high frequency (f>2GHz) its resonances are absorbed by losses in a ferrite.

Ferrite Baluns Ferrite balluns are cross between transmission lines and chokes. Ferrrite baluns are most useful between 10 kHz and 2 GHz.

Manufacturers desigh baluns for specific impedance levels and bandwitdths.

SAW filters Basic structure of Surface Acoustic Wave (SAW) resonator 1-port SAW RESONATOR has one IDT (Inter Digital Transducer), which generates and receives SAW, and two grating reflectors, which reflect SAW and generate a standing wave between the two reflectors. IDT and reflectors are fabricated on quartz crystal substrate by photolithographic process. Frequency range: from 50kHz 1GHz.

* Taken from „SAW resonators”, Murata Manufacturing Products Data Sheet, [16]

SAW filters Features of the SAW: - high Oscillation Frequency Stability - adjustment free - SAW resonator is stable against peripheral circuit or supply voltage fluctuation - simple/low cost circuit by fundamental oscillation oscillates with its fundamental mode - small size package - they can be applied Colpitts Oscillator circuit

SAW filters SAW equivalent circuit


SAW filters


Caoxial Cables d

RLCG parameters: Zo = 50, 75, 93 Ω.

ε

ε = ε '− jε ' ' R= L= C=

D For R=0, G=0:

Z0 =

L 1 = C 2π

µ 60 D ln (D / d ) ≈ ln  ε' ε reff  d 

1  1 1  +  πσδ  D d 

µ ln (D / d ) 2π 2πε '

ln (D / d ) 2πωε ' ' G= ln (D / d )

Caoxial Cables Cut-off frequency: f cut −off =

7.51

ε reff

1 D+d

Velocity of propagation: c

vp =

ε reff

Maximum peak power: E2 ln (D / d ) Pmax = D2 480 (D / d )2 max

Caoxial Cables

* Taken from „Introduction to high-speed PCB design”, Kung [11]

Caoxial Cables Why 50Ω?


Caoxial Cables


Connectors and Adapters


Connectors and Adapters


Connectors and Adapters Connector type

Cut-off frequency [GHz]

BNC

(0.3) 4

SMB

4

SMC

10

TNC

15

Type-N

18

7 mm

18

SMA

18

3.5 mm

26.5

2.9 mm

46

2.4 mm

50

Varactors Varactors applications:

Non-symetric

- harmonic generation - parametric amplification - mixing - detection - voltage variable tuning Advantages of varactors: - low loss - low noise

Symetric

Varactors

Example of varactors characteristics * Taken from „KV1911A – KV1991A VARACTOR DIODES”, Microsemi [12]

Schottky diode Schottky diode (metal-semiconductor juntion) applications: - harmonic generators (mutipliers) GHz and THz - mixers - detectors

In frequency mutliplication is used a nonlinear capacitans versus voltage.

Schottky diode

* Taken from „Surface mount microwave Schottky detector diodes HSMS 2850, HSMS 2860 series”, Hawlet Packard [13]

PIN diodes PIN diodes applications: - RF and microwave attenuators - RF and microwave tunable matching circuits - RF and microwave switches

PIN diodes

* Taken from „MA4AGBLP912 AlGaAs Beamlead PIN Diode”, Maccom Technology Solutions [14]

Bipolar junction transistors (BJTs) Base Emmiter

N

P

IE

N IB

-

UBE

+

-

UCB

Colector

IC

+

Bipolar junction transistors (BJTs) - HF bipolar transistors are NPN type because electron mobility is much higher than hole mobility - the BASE thickness is very thin to improve current gain β (hfe) - Inter-digital BASE and EMITTER contacts are employed to reduce base spreading resistance rbb’ and to reduce the noise generated by the transistor - Commercial RF transistors in discrete form can have fT up to 10GHz.

Bipolar junction transistors (BJTs)

Bias circuits of BJT – read the textbooks about basics of an electronic circuits



Bipolar junction transistors (BJTs) B

rbb'

cB'E

cB'C

B'

rB'E

C

gmUB'E

E

„Hybrid π” (Giacoletto) model of the BJT.

rCE

Bipolar junction transistors (BJTs) rB ' E =

gm =

rCE =

β I CQ ϕT I CQ

ϕT U EY I CQ

cB 'E =

cB 'C

I CQ 2πfT ϕT

=

gm

ωT

 U = cB 'C 0 1 − CB  U DC

  

−m

Hybrid π model elements. For frequencies above 300 MHz transistor should be modelled by ‘S’ parameters.


Bipolar junction transistors (BJTs) Example of HF package equivalent circuit of BJT BFP 620

* Taken from „BFP 620 NPN Silicon Germanium RF Transistor”, Product Data Sheet, 2004, Infineon Technologies [8]


* Taken from „BFR 93 - Silicon NPN Planar RF Transistor”, Product Data Sheet, 2000, Vishay [6]





FET Drain

D n

p+

Gate

G

Gate

p+

S N-channel FET Source

FET ID

UGS1 < UGS2

ID

UDS=0.1V

UDS=0.1V

n

+

+

-

barrier layer

-

p+

p+

UGS2

+

UGS1

n

-

p+

barrier layer

p+

+

FET ID

UGS1 < UGS2

ID

UDS=10V

UDS=10V

n

+

+

-

barrier layer

-

p+

p+

p+

UGS2

+

UGS1

n

-

p+

barrier layer

+

FET

Bias circuits of FET and FET with P chanel – read the textbooks about basics of an electronic circuits

MOSFET Gate

Gate Source

Source

Gate

Source

Gate Drain

Drain

Source

SiO2

SiO2

SiO2 p+

n+

p

p+

p+

n+

n

p

Base

Base

n

p

Base

Base

There are the MOSFET with two gates, too.

MOSFET UDS=0.1V

UDS=10V -

-

+

+

ID

D

ID

D

+ -

SiO2

n+

G

n+

G

p

n+

UGS

SiO2 p

n+

+

S -

N-channel MOSFET

SiO2

p+

Drain

Drain

p

n+

UGS

S

n+

MOSFET

Bias circuits of MOSFET and more information about other types of MOSFETs – read the textbooks about basics of an electronic circuits

FET and MOSFET

FET and MOSFET „hybrid π” model

FET and MOSFET

FET and MOSFET

* Taken from „ BF966S N–Channel Dual Gate MOS-Fieldeffect Tetrode, Depletion Mode”, Product Data Sheet”, 1999, Vishay Telefunken [15]

FET and MOSFET


FET and MOSFET


FET and MOSFET


FET and MOSFET


Other types of RF and microwave transistors There are other types of the microwaves transistors: - Heterostructure Bipolar Transistor (HBTs) - High Electron Mobility Transistor (HEMT) They are commercialy avaible such as the discrete elements. They are integrated in microwave IC such as i. e. LNA, power amplifiers.