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AS9100 Rev C, ISO 9001:2008,
ISO 14001:2004 and OHSAS 18001:2007

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Voltage-controlled Variable Attenuator - VCA

Features:

  • High attenuation range
  • Broadband operation
  • Low insertion loss

Applications:

  • Leveling loops
  • Receiver protection
  • Automated test equipment

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Download the VCA specsheet (.pdf)

Description

Millitech series VCA voltage-controlled variable attenuators cover the frequency range from 18 to 100 GHz. Full waveguide bandwidth performance can be achieved, upon request, up to 75 GHz (WR-15) with broadband operation beyond 75 GHz. Standard models offer attenuation levels from 30 dB at frequencies below 50 GHz, to 20 dB above 50 GHz.

If required, a higher attenuation range can be obtained at the expense of increased insertion loss. Millitech provides drivers for controlling the level of attenuation integrally to the attenuator. If a PIN switch is better suited for the application, Millitech offers a complete line of SPST, SPDT, and multi-throw PIN switches.

Electrical Specifications

Model Number VCA-42 VCA-28 VCA-22 VCA-19 VCA-15 VCA-12 VCA-10
Frequency band and range(GHz) K
18-26.5
Ka
26.5-40
Q
33-50
U
40-60
V
50-75
E
60-90
W
75-100
Standard Attenuation Version with Driver
Bandwidth (GHz) 6 10 10 10 10 10 10
Insertion loss (dB) (typ) at 0V* 1.4 1.7 1.7 2.0 2.2 2.2 2.2
Minimum attenuation at +10V (dB) 30 30 30 25 20 20 20
VSWR (max)* 2:1 2:1 2:1 2:1 2:1 2:1 2:1
Power handling (CW/peak,W) (max) 0.5/10 0.5/10 0.5/10 0.5/10 0.5/10 0.5/10 0.5/10
DC bias input (V/mA) ±12/20 ±12/20 ±12/20 ±12/20 ±12/20 ±12/20 ±12/20
Control voltage (V) 0-10 0-10 0-10 0-10 0-10 0-10 0-10
High Attenuation Version with Driver
Bandwidth (GHz) (min) 6 10 10 10 10 10 10
Insertion loss (dB) (typ) at 0V* 2.2 2.5 2.5 2.8 3.0 3.0 3.0
Minimum attenuation at +10V (dB) 40 40 40 35 30 30 25
VSWR (max)* 2:1 2:1 2:1 2:1 2:1 2:1 2:1
Power handling (CW/peak) (max) 0.5/10 0.5/10 0.5/10 0.5/10 0.5/10 0.5/10 0.5/10
DC bias input (V/mA) ±12/40 ±12/40 ±12/40 ±12/40 ±12/40 ±12/40 ±12/40
Control voltage (V) 0-10 0-10 0-10 0-10 0-10 0-10 0-10

*Measured in PASS state only.

Outline Drawings*

  Series VCA-42/28/15/12/10/08   Series VCA-22/19
Series VCA-42/28/15/12/10/08 Series VCA-22/19

*The outlines shown may not reflect the latest information. Please contact Millitech for current outline drawings.

Mechanical Specifications

Model Number VCA-42 VCA-28 VCA-22 VCA-19 VCA-15 VCA-12 VCA-10
A(in/mm) 1.40/35.56 1.39/35.31 1.70/43.18 1.70/43.18 1.25/31.75 1.25/31.75 1.25/31.75
B(in/mm) 0.88/22.4 0.75/19.1 1.13/28.7 1.13/28.7 0.75/19.1 0.75/19.1 0.75/19.1
C(in/mm) 1.90/48.26 1.38/35.05 1.21/30.73 1.20/30.48 1.00/25.4 1.00/25.4 0.75/19.1
D(in/mm) 0.58/14.6 0.38/9.5 0.56/14.3 0.56/14.3 0.38/9.5 0.38/9.5 0.38/9.5
Flange MIL.F-3922 /54.001* /54-003* /67B-006 /67B-007 /67B-008 /67B-009 /67B-010

*With #4-40 threaded holes.

How to Order

Specify Model Number
VCA-XX-ABCD0
XX = Waveguide Band
  • WR - number (42, 28, 22, 19, 15, 12, or 10)
A =Flange Type
  • R - round (WR-22 through WR-10 only)
  • S - square (WR-42 and WR-28 only)
B = Driver
  • I - internal driver (standard)
  • W - without driver
C = Bandwidth
  • N - please specify, see Electrical Specifications table for maximum bandwidth
D = Attenuation
  • S - standard attenuation version
  • H - high attenuation version

Example:

To Order: a narrowband VCA in WR-28 with a square flange, internal driver, standard attenuation, with center frequency 38 GHz and bandwidth ±2.5 GHz

Specify: VCA-28-SINS0, frequency range 38 GHz ±2.5 GHz