MICROWAVE CORPORATION
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For price, delivery, and to place orders, please contact Hittite Microwave Corporation:
12 Elizabeth Drive, Chelmsford, MA 01824 Phone: 978-250-3343 Fax: 978-250-3373
Order Online at www.hittite.com
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HMC346G8
GaAs MMIC HERMETIC SMT VOLTAGE-
VARIABLE ATTENUATOR, DC - 8 GHz
v01.0304
General Description
Features
Functional Diagram
Wide Bandwidth: DC - 8 GHz
Low Phase Shift vs. Attenuation
30 dB Attenuation Range
8 Lead Hermetic SMT Package
Electrical Specifi cations,
T
A
= +25 C, 50 ohm system
Typical Applications
The HMC346G8 is ideal for:
Basestation Infrastructure
Fiber Optics & Broadband Telecom
Microwave Radio & VSAT
Military Radios, Radar, & ECM
Test Instrumentation
The HMC346G8 is an absorptive Voltage Vari-
able Attenuator (VVA) in an 8 lead glass/metal
(hermetic) surface-mount package operating
from DC - 8 GHz. It features an on-chip reference
attenuator for use with an external op-amp to pro-
vide simple single voltage attenuation control, 0
to -3V. The device is ideal in designs where an
analog DC control signal must control RF signal
levels over a 30 dB amplitude range. Applications
include AGC circuits and temperature compensa-
tion of multiple gain stages in microwave radios
and test instrumentation.
Parameter
Min
Typical
Max
Units
Insertion Loss
DC - 6 GHz
DC - 8 GHz
2.0
2.0
3.0
3.5
dB
dB
Attenuation Range
DC - 8 GHz
30
dB
Return Loss
DC - 8 GHz
7
10
dB
Switching Characteristics
tRISE, tFALL (10/90% RF)
tON, tOFF (50% CTL to 10/90% RF)
2
8
ns
ns
Input Power for 0.25 dB Compression (0.5 - 8 GHz)
Min. Atten.
Atten. >2 dB
+8
-2
dBm
dBm
Input Third Order Intercept (0.5 - 8 GHz)
(Two-tone Input Power = -8 dBm Each Tone)
Min. Atten.
Atten. >2 dB
+25
+10
dBm
dBm
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9
-5
-4
-3
-2
-1
0
0
1
2
3
4
5
6
7
8
+ 25C
- 40C
+ 85C
INSERTION LOSS (dB)
FREQUENCY
-40
-35
-30
-25
-20
-15
-10
-5
0
0
1
2
3
4
5
6
7
8
ATTENUATION (dB)
FREQUENCY (GHz)
-25
-20
-15
-10
-5
0
0
1
2
3
4
5
6
7
8
9
10
5 dB
10 dB
15 dB
20 dB
25 dB
30 dB
RETURN LOSS (dB)
FREQUENCY (GHz)
-40
-35
-30
-25
-20
-15
-10
-5
0
0
1
2
3
4
5
6
7
8
ATTENUATION (dB)
FREQUENCY (GHz)
-3
-2.5
-2
-1.5
-1
-0.5
0
0
5
10
15
20
25
30
V1 + 25C
V2 + 25C
V1 - 40C
V2 - 40C
V1 + 85C
V2 + 85C
CONTROL VOLTAGE (Vdc)
RELATIVE ATTENUATION (dB)
-3
-2.5
-2
-1.5
-1
-0.5
0
0
5
10
15
20
25
30
V1 + 25C
V2 + 25C
V1 - 40C
V2 - 40 C
V1 + 85C
V2 + 85C
CONTROL VOLTAGE (Vdc)
RELATIVE ATTENUATION (dB)
GaAs MMIC SUB-HARMONICALLY PUMPED MIXER 17 - 25 GHz
HMC346G8
GaAs MMIC HERMETIC SMT VOLTAGE-
VARIABLE ATTENUATOR, DC - 8 GHz
v01.0304
Insertion Loss vs. Temperature
Return Loss vs. Attenuation
Relative Attenuation vs.
Control Voltage @ 8 GHz
Relative Attenuation vs.
Control Voltage @ 4 GHz
Relative Attenuation, Control Voltage
Optimized for 4 GHz Operation
Relative Attenuation, Control Voltage
Optimized for 8 GHz Operation
MICROWAVE CORPORATION
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For price, delivery, and to place orders, please contact Hittite Microwave Corporation:
12 Elizabeth Drive, Chelmsford, MA 01824 Phone: 978-250-3343 Fax: 978-250-3373
Order Online at www.hittite.com
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0
10
20
30
40
50
60
0
1
2
3
4
5
6
7
8
5 dB
10 dB
15 dB
20 dB
25 dB
30 dB
RELATIVE PHASE (DEG)
FREQUENCY (GHz)
5
10
15
20
25
30
0
1
2
3
4
5
6
7
8
THIRD ORDER INTERCEPT POINT (dBm)
FREQUENCY (GHz)
3 dB
6 dB
10 dB
0 dB
10
20
30
40
50
60
70
0
1
2
3
4
5
6
7
8
SECOND ORDER INTERCEPT POINT (dBm)
FREQUENCY (GHz)
3 dB
6 dB
10 dB
0 dB
-5
0
5
10
15
20
0
1
2
3
4
5
6
7
8
0 dB (REF)
5 dB
INPUT.25dB COMPRESSION (dBm)
FREQUENCY (GHz)
-5
0
5
10
15
20
0
1
2
3
4
5
6
7
8
0 dB (REF)
5 dB
INPUT P1dB (dBm)
FREQUENCY (GHz)
GaAs MMIC SUB-HARMONICALLY PUMPED MIXER 17 - 25 GHz
HMC346G8
Relative Phase
GaAs MMIC HERMETIC SMT VOLTAGE-
VARIABLE ATTENUATOR, DC - 8 GHz
v01.0304
Input Second Order
Intercept vs. Attenuation*
1 dB Compression vs. Attenuation
Input Third Order
Intercept vs. Attenuation*
0.25 dB Compression vs. Attenuation
20
30
40
50
60
70
80
0
1
2
3
4
5
6
7
8
SECOND HARMONIC (dBc)
FREQUENCY (GHz)
3 dB
6 dB
10 dB
0 dB
Second Harmonic vs. Attenuation
*Two-tone input power = -8 dBm each tone.
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12 Elizabeth Drive, Chelmsford, MA 01824 Phone: 978-250-3343 Fax: 978-250-3373
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Outline Drawing
Absolute Maximum Ratings
RF Input Power
+18 dBm
Control Voltage Range
+1.0 to -5.0 Vdc
Storage Temperature
-65 to +150 C
Operating Temperature
-40 to +85 C
HMC346G8
GaAs MMIC HERMETIC SMT VOLTAGE-
VARIABLE ATTENUATOR, DC - 8 GHz
v01.0304
NOTES:
1. PACKAGE MATERIAL: ALUMINA LOADED BOROSILICATE GLASS.
2. LEAD, BASE, COVER MATERIAL: KOVARTM (#7052 CORNING).
3. PLATING: ELECTROLYTIC GOLD 50 MICROINCHES MIN., OVER
ELECTROLYTIC NICKEL 50 MICROINCHES MIN.
4. DIMENSIONS ARE IN INCHES [MILLIMETERS].
5. TOLERANCES: .005 [0.13] UNLESS OTHERWISE SPECIFIED.
6. ALL GROUND LEADS AND GROUND PADDLE MUST BE SOLDERED
TO PCB RF GROUND.
MICROWAVE CORPORATION
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For price, delivery, and to place orders, please contact Hittite Microwave Corporation:
12 Elizabeth Drive, Chelmsford, MA 01824 Phone: 978-250-3343 Fax: 978-250-3373
Order Online at www.hittite.com
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T
ORS - SMT
9
HMC346G8
GaAs MMIC HERMETIC SMT VOLTAGE-
VARIABLE ATTENUATOR, DC - 8 GHz
v01.0304
Pin Number
Function
Description
Interface Schematic
1, 8
RF1, RF2
This pin is DC coupled and matched to 50 Ohm. Blocking
capacitors are required if RF line potential is not equal to 0V.
2, 7
GND
This pin must be DC grounded.
3, 6
V2, V1
Control Input (Master).
4
I
Control Input (Slave).
5
O
This pin must have an external 500 Ohm resistor to ground.
Pin Descriptions
Single-Line Control Driver
Note:
External op-amp control circuit maintains impedance
match while attenuation is varied. Input control ranges
from 0 Volts (min. attenuation) to -2.5 Volts (max.
attenuation.)
MICROWAVE CORPORATION
9 - 67
For price, delivery, and to place orders, please contact Hittite Microwave Corporation:
12 Elizabeth Drive, Chelmsford, MA 01824 Phone: 978-250-3343 Fax: 978-250-3373
Order Online at www.hittite.com
A
TTENU
A
T
ORS - SMT
9
HMC346G8
GaAs MMIC HERMETIC SMT VOLTAGE-
VARIABLE ATTENUATOR, DC - 8 GHz
v01.0304
Evaluation PCB
The circuit board used in the fi nal application should be generated with proper RF circuit design techniques. Signal
lines at the RF ports should be 50 ohm impedance and the package ground leads and package bottom should be con-
nected directly to the PCB RF ground plane, similar to that shown above. The evaluation circuit board shown above is
available from Hittite Microwave Corporation upon request.
List of Material
Item
Description
J1 - J2
PC Mount SMA RF Connector
J3 - J7
DC PIN
U1
HMC346G8
PCB*
104093-2 Eval Board
*Circuit Board Material: Rogers 4350
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