ATTENUATORS - SMT
5
5 - 84
For price, delivery, and to place orders, please contact Hittite Microwave Corporation:
20 Alpha Road, Chelmsford, MA 01824 Phone: 978-250-3343 Fax: 978-250-3373
Order On-line at www.hittite.com
HMC346G8
GaAs MMIC HERMETIC SMT VOLTAGE-
VARIABLE ATTENUATOR, DC - 8 GHz
v03.1008
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 Speci cations, TA = +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 Variable
Attenuator (VVA) in an 8 lead glass / metal (her-
metic) surface-mount package operating from DC -
8 GHz. It features an on-chip reference attenuator
for use with an external op-amp to provide 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 compensation 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
ATTENUATORS - SMT
5
5 - 85
For price, delivery, and to place orders, please contact Hittite Microwave Corporation:
20 Alpha Road, Chelmsford, MA 01824 Phone: 978-250-3343 Fax: 978-250-3373
Order On-line at www.hittite.com
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
-5
-4
-3
-2
-1
0
012345678
+ 25C
- 40C
+ 85C
INSERTION LOSS (dB)
FREQUENCY
-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 - 40C
V1 + 85C
V2 + 85C
CONTROL VOLTAGE (Vdc)
RELATIVE ATTENUATION (dB)
-40
-30
-20
-10
0
012345678
ATTENUATION (dB)
FREQUENCY (GHz)
-25
-20
-15
-10
-5
0
012345678910
5 dB
10 dB
15 dB
20 dB
25 dB
30 dB
RETURN LOSS (dB)
FREQUENCY (GHz)
-40
-30
-20
-10
0
012345678
ATTENUATION (dB)
FREQUENCY (GHz)
HMC346G8
v03.1008
GaAs MMIC HERMETIC SMT VOLTAGE-
VARIABLE ATTENUATOR, DC - 8 GHz
ATTENUATORS - SMT
5
5 - 86
For price, delivery, and to place orders, please contact Hittite Microwave Corporation:
20 Alpha Road, Chelmsford, MA 01824 Phone: 978-250-3343 Fax: 978-250-3373
Order On-line at www.hittite.com
Relative Phase
Input Second Order
Intercept vs. Attenuation*
1 dB Compression vs. Attenuation
Input Third Order
Intercept vs. Attenuation*
0.25 dB Compression vs. Attenuation
Second Harmonic vs. Attenuation
*Two-tone input power = -8 dBm each tone.
-5
0
5
10
15
20
012345678
0 dB (REF)
5 dB
INPUT.25dB COMPRESSION (dBm)
FREQUENCY (GHz)
-5
0
5
10
15
20
012345678
0 dB (REF)
5 dB
INPUT P1dB (dBm)
FREQUENCY (GHz)
20
30
40
50
60
70
80
012345678
0 dB
3 dB
6 dB
10 dB
SECOND HARMONIC (dBc)
FREQUENCY (GHz)
10
20
30
40
50
60
70
012345678
0 dB
3 dB
6 dB
10 dB
IP2 (dBm)
FREQUENCY (GHz)
5
10
15
20
25
30
012345678
0 dB
3 dB
6 dB
10 dB
IP3 (dBm)
FREQUENCY (GHz)
0
10
20
30
40
50
60
012345678
5 dB
10 dB
15 dB
20 dB
25 dB
30 dB
RELATIVE PHASE (DEG)
FREQUENCY (GHz)
HMC346G8
v03.1008
GaAs MMIC HERMETIC SMT VOLTAGE-
VARIABLE ATTENUATOR, DC - 8 GHz
ATTENUATORS - SMT
5
5 - 87
For price, delivery, and to place orders, please contact Hittite Microwave Corporation:
20 Alpha Road, Chelmsford, MA 01824 Phone: 978-250-3343 Fax: 978-250-3373
Order On-line at www.hittite.com
Outline Drawing
Absolute Maximum Ratings
RF Input Power +18 dBm
Control Voltage Range +1 to -5V
Storage Temperature -65 to +150 °C
Operating Temperature -40 to +85 °C
ESD Sensitivity (HBM) Class 1A
NOTES:
1. PACKAGE MATERIAL: ALUMINA LOADED BOROSILICATE GLASS.
2. LEAD, BASE, COVER MATERIAL: KOVAR™ (#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.
ELECTROSTATIC SENSITIVE DEVICE
OBSERVE HANDLING PRECAUTIONS
HMC346G8
v03.1008
GaAs MMIC HERMETIC SMT VOLTAGE-
VARIABLE ATTENUATOR, DC - 8 GHz
ATTENUATORS - SMT
5
5 - 88
For price, delivery, and to place orders, please contact Hittite Microwave Corporation:
20 Alpha Road, Chelmsford, MA 01824 Phone: 978-250-3343 Fax: 978-250-3373
Order On-line at www.hittite.com
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 imped-
ance match while attenuation is varied. Input con-
trol ranges from 0 Volts (min. attenuation) to -2.5
Volts (max. attenuation.)
HMC346G8
v03.1008
GaAs MMIC HERMETIC SMT VOLTAGE-
VARIABLE ATTENUATOR, DC - 8 GHz
ATTENUATORS - SMT
5
5 - 89
For price, delivery, and to place orders, please contact Hittite Microwave Corporation:
20 Alpha Road, Chelmsford, MA 01824 Phone: 978-250-3343 Fax: 978-250-3373
Order On-line at www.hittite.com
Evaluation PCB
The circuit board used in the 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 connected 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 Materials for Evaluation PCB 104095 [1]
Item Description
J1 - J2 PCB Mount SMA RF Connector
J3 - J7 DC PIN
U1 HMC346G8
PCB [2] 104093-2 Eval Board
[1] Reference this number when ordering complete evaluation PCB
[2] Circuit Board Material: Rogers 4350
HMC346G8
v03.1008
GaAs MMIC HERMETIC SMT VOLTAGE-
VARIABLE ATTENUATOR, DC - 8 GHz
