1
®
FN3663.5
HFA3101
Gilbert Cell UHF Transistor Array
The HFA3101 is an all NPN transistor array configured as a
Multiplier Cell. Based on Intersil’s bonded wafer UHF-1 SOI
process, this array achi eves very high fT (10GHz) while
maintaining excellent hFE and VBE matching characteristics
that hav e been maximized through careful attention to circuit
design and layout, making this product ideal for
communication circuits. For use in mixer applications, the
cell provides high gain and good cancellation of 2nd order
distortion terms.
Pinout HFA3101
(SOIC)
TOP VIEW
Features
Pb-free Available as an Option
High Gain Bandwidth Product (fT) . . . . . . . . . . . . . 10GHz
High Power Gain Bandwidth Product. . . . . . . . . . . . 5GHz
Current Gain (hFE). . . . . . . . . . . . . . . . . . . . . . . . . . . . .70
Low Noise Figure (Transistor) . . . . . . . . . . . . . . . . . 3.5dB
Excellent hFE and VBE Matching
Low Collector Leakage Current . . . . . . . . . . . . . . <0.01nA
Pin to Pin Compatible to UPA101
Applications
Balanced Mixers
Multipliers
Demodulators/Modulators
Automatic Gain Control Circuits
Phase Detectors
Fiber Optic Signal Processin g
Wireless Communication Systems
Wide Band Amplificati on Stages
Radio and Satellite Communications
High Performance Instrumentation
Ordering Information
PART NUMBER
(BRAND) TEMP.
RANGE (°C) PACKAGE PKG.
DWG. #
HFA3101B
(H3101B) -40 to 85 8 Ld SOIC M8.15
HFA3101BZ
(H3101B) (Note) -40 to 85 8 Ld SOIC
(Pb-free) M8.15
HFA3101B96
(H3101B) -40 to 85 8 Ld SOIC Tape
and Reel M8.15
HFA3101BZ96
(H3101B) (Note) -40 to 85 8 Ld SOIC Tape
and Reel (Pb-free) M8.15
NOTE: Intersil Pb-free products employ special Pb-free material
sets; molding compounds/die attach materials and 100% matte tin
plate termination finish, which is compatible with both SnPb and
Pb-free soldering operations. Intersil Pb-free products are MSL
classified at Pb-free peak reflow temperatures that meet or exceed
the Pb-free requirements of IPC/JEDEC J STD-020C.
1
2
3
4
8
7
6
5
Q5Q6
Q1Q2Q3Q4
NOTE: Q5 and Q6 - 2 Paralleled 3µm x 50µm Transistors
Q
1, Q2, Q3, Q4 - Single 3µm x 50µm Transistors
Data Sheet September 2004
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
1-888-INTERSIL or 321-724-7143 | Intersil (and design) is a registered trademark of Intersil Americas Inc.
Copyright © Intersil Americas Inc. 1998, 2004. All Rights Reserved
All other trademarks mentioned are the property of their respective owners.
2
Absolute Maximum Ratings Thermal Information
VCEO, Collector to Emitter Voltage . . . . . . . . . . . . . . . . . . . . . . 8.0V
VCBO, Collector to Base Voltage . . . . . . . . . . . . . . . . . . . . . . . 12.0V
VEBO, Emitter to Base Voltage . . . . . . . . . . . . . . . . . . . . . . . . . 5.5V
IC, Collector Current . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30mA
Operating Conditions
Temperature Range. . . . . . . . . . . . . . . . . . . . . . . . . . -40oC to 85oC
Thermal Resistance (Typical, Note 1) θJA (oC/W)
SOIC Package . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 185
Maximum Junction Temperature (Die). . . . . . . . . . . . . . . . . . .175oC
Maximum Junction Temperature (Plastic Package). . . . . . . . .150oC
Maximum Storage Temperature Range. . . . . . . . . . -65oC to 150oC
Maximum Lead Temperature (Soldering 10s) . . . . . . . . . . . . .300oC
(SOIC - Lead Tips Only)
CAUTION: Stresses above those listed in “Absolute Maximum Ratings” may cause permanent damage to the device. This is a stress only rating and operation of the
device at these or any other conditions above t hose indicated in the operational sections of this specification is not implied.
NOTE:
1. θJA is measured with the component mounted on an evaluation PC board in free air.
Electrical Specifications TA = 25oC
PARAMETER TEST CONDITIONS
(NOTE 2)
TEST
LEVEL MIN TYP MAX UNITS
Collector to Base Breakdown Voltage, V(BR)CBO, Q1 thru Q6IC = 100µA, IE = 0 A12 18 - V
Collector to Emitter Breakdown Voltage, V(BR)CEO,
Q5 and Q6IC = 100µA, IB = 0 A 8 12 - V
Emitter to Base Breakdown Voltage, V(BR)EBO, Q1 thru Q6IE = 10µA, IC = 0 A5.5 6 - V
Collector Cutoff Current, ICBO, Q1 thru Q4VCB = 8V, IE = 0 A - 0.1 10 nA
Emitter Cutoff Current, IEBO, Q5 and Q6VEB = 1V, IC = 0 A - - 200 nA
DC Current Gain, hFE, Q1 thru Q6IC = 10mA, VCE = 3V A40 70 -
Collector to Base Capacitance, CCB Q1 thru Q4VCB = 5V, f = 1MHz C - 0.300 -pF
Q5 and Q6-0.600 -pF
Emitter to Base Capacitance, CEB Q1 thru Q4VEB = 0, f = 1MHz B - 0.200 -pF
Q5 and Q6-0.400 -pF
Current Gain-Bandwidth Product, fTQ1 thru Q4IC = 10mA, VCE = 5V C - 10 -GHz
Q5 and Q6IC = 20mA, VCE = 5V C - 10 -GHz
Power Gain-Bandwidth Product, fMAX Q1 thru Q4IC = 10mA, VCE = 5V C - 5 - GHz
Q5 and Q6IC = 20mA, VCE = 5V C - 5 - GHz
Available Gain at Minimum Noise Figure, GNFMIN,
Q5 and Q6IC = 5mA,
VCE = 3V f = 0.5GHz C - 17.5 -dB
f = 1.0GHz C - 11.9 -dB
Minimum Noise Figure, NFMIN, Q5 and Q6IC = 5mA,
VCE = 3V f = 0.5GHz C - 1.7 -dB
f = 1.0GHz C - 2.0 -dB
50 Noise Figure, NF50, Q5 and Q6IC = 5mA,
VCE = 3V f = 0.5GHz C - 2.25 -dB
f = 1.0GHz C - 2.5 -dB
DC Current Gain Matching, hFE1/hFE2, Q1 and Q2,
Q3 and Q4, and Q5 and Q6IC = 10mA, VCE = 3V A0.9 1.0 1.1
Input Offset Voltage, VOS, (Q1 and Q2), (Q3 and Q4),
(Q5 and Q6)IC = 10mA, VCE = 3V A - 1.5 5mV
Input Offset Current, IC, (Q1 and Q2), (Q3 and Q4),
(Q5 and Q6)IC = 10mA, VCE = 3V A - 5 25 µA
Input Offset Voltage TC, dVOS/dT, (Q1 and Q2, Q3 and Q4,
Q5 and Q6)IC = 10mA, VCE = 3V C - 0.5 -µV/oC
Collector to Collector Leakage, ITRENCH-LEAKAGE VTEST = 5V B - 0.01 -nA
NOTE:
2. Test Level: A. Production Tested, B. Typical or Guaranteed Limit Based on Characterization, C. Design Typical for Information Only.
HFA3101
3-3
PSPICE Model for a 3 µm x 50 µm Transistor
.Model NUHFARRY NPN
+ (IS = 1.840E-16 XTI = 3.000E+00 EG = 1.110E+00 VAF = 7.200E+01
+ VAR = 4.500E+00 BF = 1.036E+02 ISE = 1.686E-19 NE = 1.400E+00
+ IKF = 5.400E-02 XTB = 0.000E+00 BR = 1.000E+01 ISC = 1.605E-14
+ NC = 1.800E+00 IKR = 5.400E-02 RC = 1.140E+01 CJC = 3.980E-13
+ MJC = 2.400E-01 VJC = 9.700E-01 FC = 5.000E-01 CJE = 2.400E-13
+ MJE = 5.100E-01 VJE = 8.690E-01 TR = 4.000E-09 TF = 10.51E-12
+ ITF = 3.500E-02 XTF = 2.300E+00 VTF = 3.500E+00 PTF = 0.000E+00
+ XCJC = 9.000E-01 CJS = 1.689E-13 VJS = 9.982E-01 MJS = 0.000E+00
+ RE = 1.848E+00 RB = 5.007E+01 RBM = 1.974E+00 KF = 0.000E+00
+ AF = 1.000E+00)
Common Emitter S-Parameters of 3 µm x 50 µm Transistor
FREQ. (Hz) |S11|PHASE(S11)|S12|PHASE(S12)|S21|PHASE(S21)|S22|PHASE(S22)
VCE = 5V and IC = 5mA
1.0E+08 0.83 -11.78 1.41E-02 78.88 11.07 168.57 0.97 -11.05
2.0E+08 0.79 -22.82 2.69E-02 68.63 10.51 157.89 0.93 -21.35
3.0E+08 0.73 -32.64 3.75E-02 59.58 9.75 148.44 0.86 -30.44
4.0E+08 0.67 -41.08 4.57E-02 51.90 8.91 140.36 0.79 -38.16
5.0E+08 0.61 -48.23 5.19E-02 45.50 8.10 133.56 0.73 -44.59
6.0E+08 0.55 -54.27 5.65E-02 40.21 7.35 127.88 0.67 -49.93
7.0E+08 0.50 -59.41 6.00E-02 35.82 6.69 123.10 0.62 -54.37
8.0E+08 0.46 -63.81 6.27E-02 32.15 6.11 119.04 0.57 -58.10
9.0E+08 0.42 -67.63 6.47E-02 29.07 5.61 115.57 0.53 -61.25
1.0E+09 0.39 -70.98 6.63E-02 26.45 5.17 112.55 0.50 -63.96
1.1E+09 0.36 -73.95 6.75E-02 24.19 4.79 109.91 0.47 -66.31
1.2E+09 0.34 -76.62 6.85E-02 22.24 4.45 107.57 0.45 -68.37
1.3E+09 0.32 -79.04 6.93E-02 20.53 4.15 105.47 0.43 -70.19
1.4E+09 0.30 -81.25 7.00E-02 19.02 3.89 103.57 0.41 -71.83
1.5E+09 0.28 -83.28 7.05E-02 17.69 3.66 101.84 0.40 -73.31
1.6E+09 0.27 -85.17 7.10E-02 16.49 3.45 100.26 0.39 -74.66
1.7E+09 0.25 -86.92 7.13E-02 15.41 3.27 98.79 0.38 -75.90
1.8E+09 0.24 -88.57 7.17E-02 14.43 3.10 97.43 0.37 -77.05
1.9E+09 0.23 -90.12 7.19E-02 13.54 2.94 96.15 0.36 -78.12
2.0E+09 0.22 -91.59 7.21E-02 12.73 2.80 94.95 0.35 -79.13
2.1E+09 0.21 -92.98 7.23E-02 11.98 2.68 93.81 0.35 -80.09
2.2E+09 0.20 -94.30 7.25E-02 11.29 2.56 92.73 0.34 -80.99
2.3E+09 0.20 -95.57 7.27E-02 10.64 2.45 91.70 0.34 -81.85
2.4E+09 0.19 -96.78 7.28E-02 10.05 2.35 90.72 0.33 -82.68
2.5E+09 0.18 -97.93 7.29E-02 9.49 2.26 89.78 0.33 -83.47
2.6E+09 0.18 -99.05 7.30E-02 8.96 2.18 88.87 0.33 -84.23
2.7E+09 0.17 -100.12 7.31E-02 8.47 2.10 88.00 0.33 -84.97
HFA3101
4
2.8E+09 0.17 -101.15 7.31E-02 8.01 2.02 87.15 0.33 -85.68
2.9E+09 0.16 -102.15 7.32E-02 7.57 1.96 86.33 0.33 -86.37
3.0E+09 0.16 -103.11 7.32E-02 7.16 1.89 85.54 0.33 -87.05
VCE = 5V and IC = 10mA
1.0E+08 0.72 -16.43 1.27E-02 75.41 15.12 165.22 0.95 -14.26
2.0E+08 0.67 -31.26 2.34E-02 62.89 13.90 152.04 0.88 -26.95
3.0E+08 0.60 -43.76 3.13E-02 52.58 12.39 141.18 0.79 -37.31
4.0E+08 0.53 -54.00 3.68E-02 44.50 10.92 132.57 0.70 -45.45
5.0E+08 0.47 -62.38 4.05E-02 38.23 9.62 125.78 0.63 -51.77
6.0E+08 0.42 -69.35 4.31E-02 33.34 8.53 120.37 0.57 -56.72
7.0E+08 0.37 -75.26 4.49E-02 29.47 7.62 116.00 0.51 -60.65
8.0E+08 0.34 -80.36 4.63E-02 26.37 6.86 112.39 0.47 -63.85
9.0E+08 0.31 -84.84 4.72E-02 23.84 6.22 109.36 0.44 -66.49
1.0E+09 0.29 -88.83 4.80E-02 21.75 5.69 106.77 0.41 -68.71
1.1E+09 0.27 -92.44 4.86E-02 20.00 5.23 104.51 0.39 -70.62
1.2E+09 0.25 -95.73 4.90E-02 18.52 4.83 102.53 0.37 -72.28
1.3E+09 0.24 -98.75 4.94E-02 17.25 4.49 100.75 0.35 -73.76
1.4E+09 0.22 -101.55 4.97E-02 16.15 4.19 99.16 0.34 -75.08
1.5E+09 0.21 -104.15 4.99E-02 15.19 3.93 97.70 0.33 -76.28
1.6E+09 0.20 -106.57 5.01E-02 14.34 3.70 96.36 0.32 -77.38
1.7E+09 0.20 -108.85 5.03E-02 13.60 3.49 95.12 0.31 -78.41
1.8E+09 0.19 -110.98 5.05E-02 12.94 3.30 93.96 0.31 -79.37
1.9E+09 0.18 -113.00 5.06E-02 12.34 3.13 92.87 0.30 -80.27
2.0E+09 0.18 -114.90 5.07E-02 11.81 2.98 91.85 0.30 -81.13
2.1E+09 0.17 -116.69 5.08E-02 11.33 2.84 90.87 0.30 -81.95
2.2E+09 0.17 -118.39 5.09E-02 10.89 2.72 89.94 0.29 -82.74
2.3E+09 0.16 -120.01 5.10E-02 10.50 2.60 89.06 0.29 -83.50
2.4E+09 0.16 -121.54 5.11E-02 10.13 2.49 88.21 0.29 -84.24
2.5E+09 0.16 -122.99 5.12E-02 9.80 2.39 87.39 0.29 -84.95
2.6E+09 0.15 -124.37 5.12E-02 9.49 2.30 86.60 0.29 -85.64
2.7E+09 0.15 -125.69 5.13E-02 9.21 2.22 85.83 0.29 -86.32
2.8E+09 0.15 -126.94 5.13E-02 8.95 2.14 85.09 0.29 -86.98
2.9E+09 0.15 -128.14 5.14E-02 8.71 2.06 84.36 0.29 -87.62
3.0E+09 0.14 -129.27 5.15E-02 8.49 1.99 83.66 0.29 -88.25
Common Emitter S-Parameters of 3 µm x 50 µm Transistor (Continued)
FREQ. (Hz) |S11| PHASE(S11)|S
12| PHASE(S12)|S
21| PHASE(S21)|S
22|PHASE(S
22)
HFA3101
3-5
Application Information
The HFA31 01 array is a ver y versatile RF Building block. It
has been carefully laid out to improve its matching
properties, bringing the distortion due to area mismatches,
thermal distribution, betas and ohmic resistances to a
minimum.
The cell is equivalent to two differ ential stages built as two
“variable transconductance multipliers” in parallel, with their
outputs cross coupled. This configuration is well known in
the industry as a Gilbert Cell which enables a four quadrant
multiplication operation.
Due to the input dynamic range restrictions for the input
lev els at the upper quad transistors and lower tail transistors,
the HFA3101 cell has restricted use as a linear four quadrant
multiplier. However , its configuration is well suited for uses
where its linear response is limited to one of the inputs only,
as in modulators or mixer circuit applications. Examples of
these circuits are up converters, down conv erters, frequency
doublers and frequency/phase detectors.
Although linearization is still an issue f or the lower pair input,
emitter degeneration can be used to improve the dynamic
range and consequent linearity. The HFA3101 has the lower
pair emitters brought to external pins for this purpose.
In modulators applications, the upper quad transistors are
used in a switching mode where the pairs Q1/Q2 and Q3/Q4
act as non saturating high speed switches. These switches
are controlled by the signal often referred as the carrier
input. The signal driving the lower pair Q5/Q6 is commonly
used as the modulating input. This signal can be linearly
transf erred to the output by either the use of low signal le vels
(Well below the thermal voltage of 26mV) or by the use of
emitter degeneration. The chopped wavef o rm appearing at
the output of the upper pair (Q1 to Q4) resembles a signal
that is multiplied by +1 or -1 at every half cycle of the
switching waveform.
Figure 1 shows the typical input waveforms where the
frequency of the carrier is higher than the modulating signal.
The output waveform shows a typical suppressed carrier
output of an up converte r or an AM signal generator.
Carrier suppression capability is a property of the well known
Balanced modulator in which the output must be zero when
one or the other input (carrier or modulating signal) is equal
to zero. however, at very high frequencies, high frequency
mismatches and AC offsets are always present and the
suppression capability is often degraded causing carrier and
modulating feedthrough to be present.
Being a frequency translation circuit, the balanced modulator
has the properties of translating the modulating frequency
(ωM) to the carrier frequency (ωC), generating the two side
bands ωU = ωC + ωM and ωL = ωC - ωM. Figure 2 shows
some translating schemes being used by balanced mixers.
CARRIER SIGNAL
MODULATING SIGNAL
DIFFERENTIAL OUTPUT
+1
-1
FIGURE 1. TYPICAL MODULATOR SIGNALS
FIGURE 2A. UP CONVERSION OR SUPPRESSED CARRIER AM
FIGURE 2B. DOWN CONVERSION
FIGURE 2C. ZERO IF OR DIRECT DOWN CONVERSION
FIGURE 2. MODULATOR FREQUENCY SPECTRUM
ωC + ωM
ωC - ωM
ωC
IF (ωC - ωM)
FOLDED BACK ωM
ωC
BASEBAND
ωC
ωM
HFA3101
6
The use of the HFA310 1 as modulators has several
advantages when compared to its counterpart, the diode
doublebalanced mixer, in which it is required to receive
enough energy to drive the diodes into a switching mode and
has also some requirements depending on the frequency
range desired, of different transformers to suit specific
frequency responses. The HFA3101 requires very low
driving capa bilities for its carrier input and its frequency
response is limited by the fT of the devices, the design and
the layout techniques being utilized.
Up conversion uses, f or UHF transmitters f or e xample , can be
perf ormed by injecting a modulating input in the range of
45MHz to 130MHz that carries the inf ormation often called IF
(Intermediate frequency) for up conversion (The IF signal has
been previously modulated by some modulation scheme from a
baseband signal of audio or digital information) and by injecting
the signal of a local oscillator of a much higher frequency range
from 600MHz to 1.2GHz into the carrier input. Using the
ex ample of a 850MHz carrier input and a 70MHz IF, the output
spectrum will contain a upper side band of 920MHz, a lower
side band of 780MHz and some of the carrier (850MHz) and IF
(70MHz) f eedthrough. A Band pass filter at the output can
attenuate the undesirable signals and the 920MHz signal can
be routed to a transmitter RF powe r amplifier.
Down conversion, as the name implies, is the process used
to translate a higher frequency signal to a lower frequency
range con s erving the modul a ti on inf ormation cont ai n ed in
the higher frequency signal. One very common typical down
conversion use for example, is for superhetero dyne radio
receivers where a translated lower frequency often referred
as intermediate frequency (IF) is used for detection or
demodulation of the baseband signal. Other application uses
include down con version for special filtering using frequency
translation methods.
An oscillator referred as the local oscillator (LO) drives the
upper quad transistors of the cell with a frequency called
ωC . The lower pair is driven by the RF signal of frequency
ωM to be translated to a lower frequency IF . The spectrum of
the IF output will contain the sum and difference of the
frequencies ωC and ωM. Notice that the difference can
become negative when the frequency of the local oscillator is
lower than the incoming frequency and the signal is folded
back as in Figure 2.
NOTE: The acronyms R F , IF and LO are often interchanged in the
industry depending on the application of the cell as mixers or
modulators. The output of the cell also contains multiples of the
frequency of the signal being fed to the upper quad pair of transistors
because of the switching action equivalent to a square wave
multiplication. In practice, however, not only the odd multiples in the
case of a symmetrical square wave but some of the even multiples
will also appear at the output spectrum due to the nature of the actual
s witching wav ef orm and high frequency performance. By-products of
the form M*ωC + N*ωM with M and N being positive or negative
integers are also ex pected to be present at the output and their le vels
are carefully examined and minimized by the design. This distor tion
is considered one of the figures of merit for a mixer application.
The process of frequency doubling is also understood by
having the same signal being fed to both modulating and
carrier ports. The output frequency will be the sum of ωC
and ωM which is equivalent to the product of the input
frequency by 2 and a zero Hz or DC frequency equiv alent to
the difference of ωC and ωM . Figure 2 also shows one
technique in use today where a process of down conversion
named zero IF is made by using a local oscillator with a very
pure signal frequency equal to the incoming RF frequency
signal that contains a baseband (audio or digital signal)
modulation. Although complex, the extraction or detection of
the signal is straightforward.
Another useful application of the HFA3101 is its use as a high
frequency phase detector where the two signals are fed to the
carrier and modulation ports and the DC information is
extracted from its output. In this case, both ports are utilized in a
s witching mode or ov erdrive , such that the process of
multip licatio n tak es place i n a quasi digi tal f orm (2 square
wa v es). One application of a phase detector is frequency or
phase demodulation where the FM signal is split before the
modulating and carrier ports. The lower input port is alwa ys 90
degrees apart from the carrier input signal through a high Q
tuned phase shift network. The network, being tuned for a
precise 90 degrees shift at a nominal frequency, will set the two
signals 90 degrees apart and a quiescent output DC lev el will
be present at the output. When the input signal is frequency
modulated, the phase shift of the signal coming from the
network will deviate from 90 degrees proportional to the
frequency deviation of the FM signal and a DC v ariation at the
output will take place, resemb ling the demodulated FM signal.
The HFA3101 could also be used for quadrature detection,
(I/Q demodulation), AGC control with limited range , lo w le vel
multiplication to name a few other applications.
Biasing
Various biasing schemes can be employed for use with the
HFA3101. Figure 3 shows the most common schemes. The
biasing method is a choice of the designer when cost,
ther mal dependence, voltage overheads and DC balancing
properties are taken into consideration.
Figure 3A shows the simplest form of biasing the HFA3101.
The current source required for the lower pair is set by the
voltage across the resistor RBIAS less a VBE drop of the
lower tr ansistor . To increase the overhead, collector resistors
are substituted by an RF choke as the upper pair functions
as a current source for AC signals. The bases of the upper
and lower transistors are biased by RB1 and RB2
respectively. The voltage drop across the resistor R2 must
be higher than a VBE with an increase sufficient to assure
that the collector to base junctions of the lower pair are
always re verse biased. Notice that this same voltage also
sets the VCE of operation of the lower pair which is important
for the optimization of gain. Resistors REE are nominally
zero for applications where the input sign als are well below
25mV peak. Resistors REE are used to increa se the linea rity
HFA3101
3-7
of the circuit upon higher level signals. The drop across REE
must be taken into consideration when setting the current
source value.
Figure 3B depicts the use of a common resistor sharing the
current through the cell which is used for temperature
compensation as the lower pair VBE dr op at the rate of
-2mV/oC.
Figure 3C us es a sp li t su pp l y.
Design Example: Down Converter Mixer
Figure 4 shows an example of a low cost mixer for cellular
applications.
The design fle xibility of the HFA3101 is demonstrated by a
low cost, and low voltag e mixer application at the 900MHz
range. The choice of good quality chip components with their
self resonance outside the boundaries of the application are
important. The design has been optimized to accommodate
the evaluation of the same layout for various quiescent
current values and lower supply voltages. The choice of RE
became important for the available overhead and also for
maintaining an AC true impedance for high frequency
signals. The value of 27 has been found to be the optimum
minimum for the application. The input impedances of the
HFA3101 base input ports are high enough to permit their
termination with 50 resistors. Notice the AC termination by
decoupling the bias circui t through good quality capacitors.
The choice of the bias has been rela ted to the available
power supply voltage with the values of R1, R2 and RBIAS
splitting the voltages f or optimum VCE values. F or evaluation
of the cell quiescent currents, the voltage at the emitter
resistor RE has been recorded.
The gain of the circuit, being a function of the load and the
combined emitter resistances at high frequencies have been
kept to a maximum by the use of an output match network.
The high output impedance of the HFA3101 permits
FIGURE 3A. FIGURE 3B. FIGURE 3C.
FIGURE 3.
VCC
RB1
R1
R2
RBIAS
RE
REE
REE
LCH
1
2
3
4
8
7
6
5
Q5Q6
Q1Q2Q3Q4
RB2
VCC
RB1
R1
R2
RBIAS
RE
REE
REE
1
2
3
4
8
7
6
5
Q5Q6
Q1Q2Q3Q4
RB2
RC
LCH
VEE
RB1
R1
RBIAS
RE
REE
REE
1
2
3
4
8
7
6
5
Q5Q6
Q1Q2Q3Q4
RB2
VCC
LCH
R2
27
LCH
1
2
3
4
8
7
6
5
Q5Q6
Q1Q2Q3Q4
VCC
390nH
0.01
0.01
110
220
0.1
VCC3V
75MHz
2K
5p T O 12p
LO IN
51
825MHz
51
900MHz
IF OUT
RF IN
0.01
0.01
0.01 330
FIGURE 4. 3V DOWN CONVERTER APPLICATION
HFA3101
8
broadband match if so desired at 50 (RL = 50 to 2k) as
well as with tuned medium Q matching networks (L, T etc.).
Stability
The cell, by its nature, has very high gain and precautions
must be taken to account for the combination of signal
reflections, gain, layout and package parasitics. The rule of
thumb of avoiding reflected waves must be observed. It is
important to assure good matching between the mixer stage
and its front end. Laboratory measurements have shown
some susceptibility for oscillation at the upper qua d
transistors input. Any LO prefiltering has to be designed
such the return loss is maintained within accep ta ble limits
specially at high frequencies. Typical off the shelf filters
exhibits ver y po or return loss for signals outside the
passband. It is suggested that a “pad” or a broadband
resistive network be used to interface the LO port with a
filter. The inclusion of a parallel 2K resistor in the load
decreases the gain slightly which improves the stability
factor and also improves the distor tion products (output
inter m odulation or 3rd order intercept). The employment of
good RF techniques shall suffice the stability requirements.
Evaluation
The evaluation of the HFA310 1 in a mixer configuration is
presented in Figures 6 to 11, Table 1 and Table 2. The lay out
is depicted in Figure 5.
The output matching network has been designed from data
taken at the output port at various test frequencies with the
setup as in Table 1. S22 characterization is enough to assure
the calculation of L, T or transmission line matching
networks.
FIGURE 5. UP/DO WN CONVERTER LAY OUT , 400%;
MATERIAL G10, 0.031
TABLE 1. S22 PARAMETERS FOR DO WN CONVERSION,
LCH = 10µH
FREQUENCY RESISTANCE REACTANCE
10MHz 265615
45MHz 420- 735
75MHz 122- 432
100MHz 67- 320
TABLE 2. TYPICAL P ARAMETERS FOR DO WN
CONVERSION, LCH = 10µH
PARAMETER LO LEVEL VCC = 3V,
IBIAS = 8mA
Power Gain -6dBm 8.5dB
TOI Output -6dBm 11.5dBm
NF SSB -6dBm 14.5dB
Power Gain 0dBm 8.6dB
TOI Output 0dBm 11dBm
NF SSB 0dBm 15dB
PARAMETER LO LEVEL VCC = 4V,
IBIAS = 19mA
Power Gain -6dBm 10dB
TOI Output -6dBm 13dBm
NF SSB -6dBm 20dB
Power Gain 0dBm 11dB
TOI Output 0dBm 12.5dBm
NF SSB 0dBm 24dB
TABLE 3. TYPICAL V ALUES OF S22 FOR THE OUTPUT PORT.
LCH = 390nH IBIAS = 8mA (SET UP OF FIGURE 11)
FREQUENCY RESISTANCE REACTANCE
300MHz 22-115
600MHz 7.5-43
900MHz 5.2-14
1.1GHz 3.90
TABLE 4. TYPICAL VALUES OF S22. LCH = 390nH, IBIAS = 18mA
FREQUENCY RESISTANCE REACTANCE
300MHz 23.5-110
600MHz 10.3-39
900MHz 8.7-14
1.1GHz 80
HFA3101
3-9
Up Converter Example
An application for a up converter as well as a frequency
multiplier can be demonstrated using the same layout, with
an addition of matching components. The output port S22
must be characterized for proper matching procedures and
depending on the frequency desired for the output,
transmission line transformations can be designed. The
retur n loss of the input ports maintain acceptable values in
excess of 1.2GHz which can permit the evaluation of a
frequency doubler to 2.4GHz if so desired.
The addition of the resistors REE can increase considerably
the dynamic range of the up converte r as demonstrated at
Figure 13. The evaluation results depicted in Table 5 have
been obtained by a triple stub tuner as a matching network
for the output due to the layout constraints. Based on the
evaluation results it is clear tha t the cell requires a higher
Bias current for overall performance.
FIGURE 6. OUTPUT PORT S22 TEST SET UP FIGURE 7. LO PORT RETURN LOSS
FIGURE 8. RF PORT RETURN LOSS FIGURE 9. IF PORT RETURN LOSS, WITH MATCHING
NETWORK
FIGURE 10. TYPICAL IN BAND OUTPUT SPECTRUM, VCC = 3V FIGURE 11. TYPICAL OUT OF BAND OUTPUT SPECTRUM
VCC 3V
0.1
LCH
1
2
3
4
8
7
6
5
Q5Q6
Q1Q2Q3Q4
2K
S11
0dB
5dB/DIV
100MHz 1.1GHz
LOG MAG
3V
4V
0dB
10dB/DIV
100MHz 1.1GHz
S11 LOG MAG 0dB
5dB/DIV
10MHz
S22 LOG MAG
110MHz
76MHz
64M
11*LO - 10RF 88M
12RF - 13LOIF
SPAN
40MHz
LO = 825MHz -6dBm
RF = 901MHz - 25dBm
-17dBm
10dB/
DIV
675 750 825 900 975
10dB/
DIV
LO + 2RF
SPAN
500MHz
LO - 2RF
-26dBm
-36dBm
-58dBm
-53dBm
LO = 825MHz -6dBm
RF = 900MHz -25dBm
HFA3101
10
Design Example: Up Converter Mixer
Figure 12 shows an example of an up converter for cellular
applications.
Conclusion
The HFA3101 offers the designer a number of choices and
different applications as a powerful RF building block.
Although isolation is degraded from the theoretical results for
the cell due to the unbalanced, nondifferential input schemes
being used, a number of advantages can be taken into
consideration like cost, fle xibility, low power and small outline
when deciding for a design.
TABLE 5. TYPICAL PARAMETERS FOR THE UP
CONVERTER EXAMPLE
PARAMETER VCC = 3V,
IBIAS = 8mA VCC = 4V,
IBIAS = 18mA
Power Gain, LO = -6dBm 3dB 5.5dBm
Power Gain, LO = 0dBm 4dB 7.2dB
RF Isolation, LO = 0dBm 15dBc 22dBc
LO Isolation, LO = 0dBm 28dBc 28dBc
FIGURE 12. UP CONVERTER
FIGURE 13. TYPICAL SPECTRUM PERFORMANCE OF UP CONVERTER
RF IN
0.01
390nH
900MHz
5.2nH
VCC 3V
0.1
1
2
3
4
8
7
6
5
Q5Q6
Q1Q2Q3Q4
11p
0.01 75MHz
27
220
REE REE 51
LO IN
VCC
0.01
0.01 110
330
3V
825MHz
0.01
0.01
51
47-100pF
901 912890
2LO - 10RF 12RF
OUTPUT WITHOUT EMITTER DEGENERATION
RF = 76MHz
LO = 825MHz
SPAN
50MHz
OUTPUT WITH EMITTER DEGENERA TION REE = 4 .7
825 900 976
EXPANDED SPECTRUM REE = 4.7
HFA3101
3-11
Typical Performance Curves for Transistors
FIGURE 14. IC vs VCE FIGURE 15. HFE vs IC
FIGURE 16. GUMMEL PLOT FIGURE 17. fT vs IC
FIGURE 18. GAIN AND NOISE FIGURE vs FREQUENCY
NOTE: Figures 14 through 18 are only for Q5 and Q6.
VCE (V)
IC (mA)
02.0 6.04.0
0
70
60
50
40
30
20
10
IB = 800µA
IB = 1mA
IB = 200µA
IB = 400µA
IB = 600µA
hFE
IC (A)
10-10 10-8 10-6 10-4 10-2 100
140
120
100
80
60
40
20
0
VCE = 5V
VBE (V)
IC AND IB (A)
10-10
10-8
10-6
10-4
10-2
100
10-12
0.20 0.40 0.60 0.80 1.0
VCE = 3V
IC (A)
fT (GHz)
12
10
8
6
4
2
0
10-4 10-3 10-2 10-1
20
18
16
14
12
10
4
6
NOISE FIGURE (dB)
FREQUENCY (GHz)
|S21| (dB)
0.5 1.51.0 2.002.53.0
4.8
4.6
4.4
4.2
4.0
3.8
3.6
3.4
3.2
8
HFA3101
12
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Die Characteristics
PROCESS
UHF-1
DIE DIMENSIONS:
53 mils x 52 mils x 14 mils
1340µm x 1320µm x 355.6µm
METALLIZATION:
Type: Metal 1: AlCu(2%)/TiW
Thickness: Metal 1: 8kÅ ±0.5kÅ
Type: Metal 2: AlCu(2%)
Thickness: Metal 2: 16kÅ ±0.8kÅ
PASSIVATION:
Type: Nitride
Thickness: 4kÅ ±0.5kÅ
SUBSTRATE POTENTIAL (Powered Up):
Floating
Metallization Mask Layout HFA3101
1
1
2233
4
4
5
5
6
6
77
8
8
HFA3101