ALPHA AV850M2-00 Datasheet

Alpha Industries, Inc. [781] 935-5150 • Fax [617] 824-4579 • Email [e-mail] • www.alphaind.com 1

Specifications subject to change without notice. 9/00A

18–40 GHz GaAs MMIC
Voltage V ariable Attenuator

Features

■ Dual Voltage Control

■ 35 dB Attenuation Range

■ Triple Gate 0.25 µm MESFET Design

■ +10 dBm P

1 dB

All Attenuation States

■ 100% On-Wafer RF and DC Testing

■ 100% Visual Inspection to MIL-STD-883

MT 2010

Chip Outline

AV850M2-00

Description

Alpha’s AV850M2-00 MMIC voltage variable attenuator
is a standard TEE configuration incorporating triple-gate

0.25 µm power MESFETs.The attenuator has a typical
insertion loss of 3 dB over the 18–40 GHz band. The
attenuation range is 35 dB while typical I/P and O/P return
loss is better than 6 dB.The chip uses Alpha’s prov en 0.25
µm MESFET technology and is based upon MBE layers
and electron beam lithography f or the highest uniformity
and repeatability .The MMICs employ surf ace passivation
to ensure a rugged, reliable part with through-substrate
via holes and gold-based backside metallization to
facilitate a conductive epo xy die attach process.This chip
incorporates triple-gate FETs which results in less
attenuation variation over temperature as well as better
power handling performance at all attenuation states.All
chips are screened for insertion loss, full attenuation and
I/P and O/P match over the 18–40 GHz band for
guaranteed performance.

Parameter Condition Symbol Min. Typ.

2

Max. Unit

Maximum Attenuation VC= -1 V, VC2= -0.25 V

F = 18–35 GHz ISO 20 30 dB

Minimum Attenuation VC= -1 V, VC2= -3.25 V

F = 18–35 GHz I

L

23dB
Input/Output Return Loss F = 18–35 GHz RL -10 -6 dB
Maximum Attenuation VC= 0 V, VC2= -0.8 V

F = 35–40 GHz ISO 20 35 dB

Minimum Attenuation VC= 0 V, VC2= -3.25 V

F = 35–40 GHz I

L

34dB
Input/Output Return Loss F = 35–40 GHz RL -10 -5 dB
Input Power at 1 dB Compression

(For All Attenuation Levels)

1

P

1 dB

10 dBm

Thermal Resistance Θ

JC

101 °C/W

Electrical Specifications at 25°C

0.000

0.000

0.314

0.750

0.097

1.500

0.982

0.911

1.050

Dimensions indicated in mm.
All DC (V) pads are 0.1 x 0.1 mm and RF In, Out pads are 0.07 mm wide.
Chip thickness = 0.1 mm.

Characteristic Value

Operating Temperature (TC) -55°C to +90°C
Storage Temperature (TST) -65°C to +150°C
Control Voltage (VC)-7 V

DC

Power In (PIN) 30 dBm
Junction Temperature (TJ) 175°C

Absolute Maximum Ratings

1. Not measured on a 100% basis. 2.Typical represents the median parameter value across the specified
frequency range for the median chip.

18–40 GHz GaAs MMIC Voltage Variable Attenuator AV850M2-00

2 Alpha Industries, Inc. [781] 935-5150 • Fax [617] 824-4579 • Email [e-mail] • www.alphaind.com

Specifications subject to change without notice. 9/00A

Attenuation vs. Frequency (VC1 = 0 V)

Frequency (GHz)

-45

-35

-40

20 22 24 26 28 30 36 38 4032 34 46 4842 44 50

-30

-25

-20

-15

-10

-5

Attenuation (dB)

0

-0.2

0.0

-0.4

-0.6

-0.8

-1.0

-1.2

-1.4

-1.6 – -3.0

V

C2

:

Example Chip-to-Chip Variation for Any

Single-Frequency of Operation

(Low-Frequency Band)

Control V oltage VC2 (V)

Attenuation (dB)

-40

-35

-30

-25

-20

-15

-10

-5

0

-3.25 -0.25

Knee
Voltage 1

Knee
Voltage 2

Knee
Voltage 3

VC1 = -1V

*

*

Example Chip 3

Example Chip 2

Example Chip 1

Attenuation vs. 1.0 dB Compression

Attenuation (dB)

10

8
6
4
2
0

-2

-20 -18 -16 -14 -12 -10 -8 -6 -4 -2 0

12

14

16

18

20

22

24

26

Input Power at 1 dB

28

Attenuation vs. Control Voltage

Control V oltage VC2 (V)

-3.0 -2.6 -2.2 -1.8 -1.4 -0.6 -0.2-1.0 0

Attenuation (dB)

-45

-35

-40

-30

-25

-20

-15

-10

-5

0

20 GHz

30 GHz

40 GHz

50 GHz

VC1 = 0 V

Typical Performance Data

RF

V

C2

V

C1

RF

Bias Arrangement

V

C2

V

C1

RF OUTRF IN

Circuit Schematic

VC1controls the series devices, adjust for optimum VSWR.
V

C2

controls the shunt devices, adjust to set attenuation.

Recommended Control Voltages:

For frequency 18–35 GHz: V

C1

= -1 V, VC2= -0.25 to -3.25 V.

For frequency 35–40 GHz: V

C1

= 0 V, VC2= -0.8 to -3.25 V.

*Asterisk in graph indicates guaranteed attenuation limits from the Electrical

Specification table (knee voltage can vary from -3.25 V to approximately -1.0 V).