Datasheet HMC121C8 Datasheet (Hittite)

MICROWAVE CORPORATION

HMC121C8

GaAs MMIC SMT VOLTAGE-VARIABLE ATTENUATOR DC - 10 GHz

2

ATTENUATORS

SMT

FEBRUARY 2001

Features

WIDE BANDWIDTH: DC - 10 GHz

LOW PHASE SHIFT VS. ATTENUATION

25 dB ATTENUATION RANGE

SIMPLIFIED VOLTAGE CONTROL

V03.0400

General Description

The HMC121C8 is an absorptive Voltage
Variable Attenuator (VVA) in a non-hermetic
surface-mount package covering DC - 10
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 25 dB
amplitude range. Applications include AGC
circuits and temperature compensation of
multiple gain stages in microwave point-to­point and VSAT radios. See HMC121G8
for a hermetic SMT version of this device.

Guaranteed Perf ormance, 50 ohm system, -55 to +85 deg C

Parameter Min Typical Max Units

Insertion Loss DC -6 GHz :

Attenuation Range DC - 6 GHz:

Return Loss DC -8 GHz:

S witching Characteristics

tRISE,tFALL (10/90% RF):

tON, tOFF (50% CTL to 10/90% R F):

Input Power for 0. 25 dB Compression
(0.5 - 10 GHz)

Input Third Order Intercept (two - 8 dBm
signals, 0.5 - 10 GHz)

12 Elizabeth Drive, Chelmsford, MA 01824 Phone: [phone] Fax: [phone] Web Site: www.hittite.com

DC -8 GHz:
DC -10 GHz :

DC - 10 GHz:

DC - 10 GHz:

Min. Atten:
Atten.>2 dB:

Min. Atten: +18

20
25

11

8

2 - 14

2.0

2.2

3.5
25

30
15

12

3
6

+3

-3

+10

2.5

3.2

4.5

dB
dB
dB

dB

dB
dB

ns
ns

dBm
dBm

dBm
dBm

HMC121C8

MICROWAVE CORPORATION

HMC121C8 SMT VOLTAGE-VARIABLE ATTENUATOR DC - 10 GHz

V03.0400

Insertion Loss Relative Attenuation

0

-1

-2

-3

INSERTION LOSS (dB)

-4

-5
024681012

FREQUENCY (GHz)

-40 C
+25 C

+85 C

0

-10

-20

ATTENUATION (dB)

-30

24 dB

-40
024681012

6dB

18 dB

FREQUENCY (GHz)

Relative Attenuation vs.

Return Loss

0

-5

-10

-15

-20

-25

RETURN LOSS (dB)

-30

-35
024681012

FREQUENCY (GHz)

S11

S22

Control Voltage @ 4.2 GHz

0

-0.5

-1

-1.5

-2

CONTROL VOLTAGE (Vdc)

-2.5

-3
0 5 10 15 20 25 30

RELATIVE ATTENUATION (dB)

V1

Relative Attenuation vs.

Relative Phase

85
75
65
55
45
35
25
15

RELATIVE PHASE (DEG)

5

-5
024681012

9dB

3dB

24 dB

21 dB

15 dB

FREQUENCY (GHz)

Control Voltage @ 10 GHz

0

-0.5

-1

-1.5

-2

CONTROL VOLTAGE (Vdc)

-2.5

-3
0 5 10 15 20 25 30

RELATIVE ATTENUATION (dB)

V1

FEBRUARY 2001

3dB

12 dB

V2

V2

0dB

2

ATTENUATORS

SMT

12 Elizabeth Drive, Chelmsford, MA 01824 Phone: [phone] Fax: [phone] Web Site: www.hittite.com

2 - 15

HMC121C8

MICROWAVE CORPORATION

HMC121C8 SMT VOLTAGE-VARIABLE ATTENUATOR DC - 10 GHz

2

ATTENUATORS

SMT

FEBRUARY 2001

Input Third Order
Intercept vs. Attenuation

30

25

20

15

10

THIRD ORDER INTERCEPT (dBm)

5

012345678910

Reference

10 dB

6dB

3dB

FREQUENCY (GHz)

0.25 dB Compression
vs. Attenuation

15

10

5

6dB

0

-5

0.25 dB COMPRESSION (dBm)

-10
012345678910

Reference

FREQUENCY (GHz)

Input Second Order
Intercept vs. Attenuation

SECOND ORDER INTERCEPT (dBm)

60

50

40

30

20

10

Reference

6dB

012345678910

FREQUENCY (GHz)

10 dB

1 dB Compression
vs. Attenuation

15

Reference

10

5

0

-5

1 dB COMPRESSION (dBm)

-10
012345678910

6dB

FREQUENCY (GHz)

V03.0400

3dB

Second Harmonic vs. Attenuation

70

Reference

60

50

40

SECOND HARMONIC (dBc)

30

012345678910

FREQUENCY (GHz)

12 Elizabeth Drive, Chelmsford, MA 01824 Phone: [phone] Fax: [phone] Web Site: www.hittite.com

2 - 16

3dB

6dB

10 dB

HMC121C8

MICROWAVE CORPORATION

HMC121C8 SMT VOLTAGE-VARIABLE ATTENUATOR DC - 10 GHz

V03.0400

Schematic

50 50

500

Outline Drawing

FEBRUARY 2001

Absolute Maximum Ratings

RF Input +16dBm

RF2RF1

500500

500

V1OIV2

Control Voltage Range +1.0 to -6.0 Vdc
Storage Temperature -65 to +150 deg C
Operating Temperature -55 to +85 deg C

2

ATTENUATORS

SMT

1. MATERIAL:
A) PACKAGE BODY & COVER : WHITE ALUMINA (92%)
B) LEADS & PACKAGE BOTTOM: COPPER

2 . PLATING : ELECTROLYTIC GOLD 100 - 200 MICROINCHES

OVER ELECTROLYTIC NICKEL 100 TO 200 MICROINCHES.

3. DIMENSIONS ARE IN INCHES (MILLIMETERS).
UNLESS OTHERWISE SPECIFIED TOL. ARE ±0.005(±0.13).

4. ALL UNLABELED LEADS ARE GROUND. THESE LEADS ARE
CONNECTED INTERNALLY TO THE PACKAGED BOTTOM GROUND.
THE PACKAGE BOTTOM RF GROUND MUST BE SOLDERED TO
THE PCB RF GROUND.

5. PACKAGE LENGTH AND WIDTH DIMENSIONS SHOWN DO NOT INCLUDE
LID SEAL PROTRUSION. ALLOWABLE PROTRUSION SHALL BE 0.005
(0.127MM) PER SIDE.

12 Elizabeth Drive, Chelmsford, MA 01824 Phone: [phone] Fax: [phone] Web Site: www.hittite.com

2 - 17

HMC121C8

MICROWAVE CORPORATION

HMC121C8 SMT VOLTAGE-VARIABLE ATTENUATOR DC - 10 GHz

2

ATTENUATORS

SMT

FEBRUARY 2001

Single-Line Control Driver

50 50

500

3.9K

1N4148

3.9K500

+5V

TL321
OR EQUIVALENT

V02.0400

RF2RF1

500500

500

V1OIV2

CTL

500

-5V

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.)

12 Elizabeth Drive, Chelmsford, MA 01824 Phone: [phone] Fax: [phone] Web Site: www.hittite.com

2 - 18

HMC121C8

MICROWAVE CORPORATION

HMC121C8 SMT VOLTAGE-VARIABLE ATTENUATOR DC - 10 GHz

V02.0400

Evaluation PCB

FEBRUARY 2001

2

ATTENUATORS

SMT

The circuit board used in the final application should be generated with proper RF circuit design techniques.
Signal lines at the RF port should have 50 ohm impedance and the package ground leads and package bottom
ground should be connected directly to the 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 DCPIN
U1 HMC121C8
PCB

*

* Circuit Board Material : Rogers 4350

12 Elizabeth Drive, Chelmsford, MA 01824 Phone: [phone] Fax: [phone] Web Site: www.hittite.com

102084 Eval Board

VVA

2 - 19