
Agilent 
33304/5 
Programmable 
Step Attenuators
Data Sheet
Features and description
•
Rapid switching (less than 0.05 second)
•
High repeatability (0.05 dB typical)
•
Broadband (DC to 18 GHz)
•
Two ranges and step sizes
Discontinued Product Information
— For Support Reference Only —
Information herein, may refer to products/services no longer supported. We regret any 
inconvenience caused by obsolete information. For the latest information on Agilent’s 
test and measurement products go to: www.agilent.com/find/products
In the US, call Agilent Technologies at 1-800-829-4444 
(any weekday between 8am–5pm in any U.S. time zone)
World-wide Agilent sales office contact information is available at:
www.agilent.com/find/contactus
 

2
The 33300 Programmable Step Attenuators provide a fast and precise means 
for electrically controlling the level of signal attenuation in automatic test 
systems, receivers, and other RF equipment. They provide attenuation up 
to 110 dB in 1 or 10 dB steps over a frequency range of dc to 18 GHz.
The products are defined as:
Model no. Total attenuation  Step size 
dB dB 
33304 11 1 
33305 110 10
The 33300 series attenuators utilize a unique operating principle. Magnetic 
latching solenoids are used to switch individual attenuation elements 
(tantalum resistive films on sapphire substrates) into and out of contact 
with a 50-ohm transmission line. Each unit is comprised of three or 
four attenuation sections. By energizing the appropriate solenoid, any 
combination of these sections may be put across the 50-ohm transmission 
line to give the desired levels of attenuation.
The extreme stability of the sapphire tantalum attenuator pads, combined 
with the elimination of sliding contacts, gives rise to a product that has as 
number of important operational features. Among these are fast switching 
speed, excellent repeatability, compact size, long life, and high stability.
Magnetic latching solenoids move the transmission line into and out of 
contact with the sapphire attenuator elements. These solenoids are supplied 
with coils for 24-volt operation. The 24-volt coil can be run at up to 30 volts.
Because the solenoids are of the latching type, power need not be 
continuously maintained to keep the solenoid in either the in or the out 
position. It is sufficient to pulse the solenoid for 30 milliseconds at its rated 
voltage to change states. To change states the polarity across the terminals 
must be reversed. However, both terminals are “floating,” so either can 
be grounded. Thus, unipolar power supplies are sufficient for controlling 
these units.
For switching speeds faster than 30 ms, this pulse voltage can be increased. 
A maximum of double the rated voltage may be put across the solenoids 
in such cases, but pulse width should be limited to keep average solenoid 
power below 3.3 watts per section.
Indicator contacts, which allow the user to determine whether a given 
section is engaged or not, can be included. These contacts are in their 
open position when the appropriate attenuator cards are not engaged. 
The contacts close, and remain closed, when the appropriate card moves 
into contact with the transmission line.
The 33300 series is available with any combination of 3 mm, 7 mm or 
Type N connectors. A three-digit code specifies these options. The first 
digit is always 0. The second digit calls out port 1, the third, port 2. 
See figure 2 for details.
Description
 

3
Figure 3. Outline drawings
Figure 2. Ordering example
Figure 1. Electrical diagram and 
programming table
 

Electrical 
Frequency range: DC-18 GHz  
Characteristic impedance: 50 ohms  
Attenuation ranges:
Model Range (dB) Step size (dB) 
33304 0–11 1
33305 0–110 10
Life, minimum: 1,000,000 steps each section.  
Power sensitivity: 0.001 dB/dB/ watt.  
Attenuation temperature coefficient: Less than 0.0001 dB/dB° C  
Repeatability, typical:
DC–12.4 GHz  0.03 dB
12.4–18 GHz  0.05 dB
Attenuation accuracy (±dB) referenced from 0 dB setting:
33304
DC–4 GHz 0.2 0.2 0.3 0.3 0.3 0.3 0.4 0.4 0.4 0.4 0.5 
4–12.4 GHz 0.3 0.3 0.4 0.4 0.4 0.4 0.5 0.5 0.5 0.5 0.6
12.4–18 GHz 0.5 0.5 0.6 0.6 0.7 0.8 0.8 0.8 0.8 0.8 0.9
33305
Frequency range Attenuator setting (dB) 
DC–12.4 GHz 0.5 0.7 0.9 1.2 1.5 1.8 2.1 2.4 2.7 3.0 3.3
12.4–18 GHz 0.6 0.8 1.2 1.6 2.0 2.4 2.8 3.2 3.6 4.0 4.4
Note: The attenuation sections 3 and 4 of both the 33304 and 33305 have equal attenuation values. 
There are attenuator configurations which require only one of those to be activated. The above 
accuracy specifications are guaranteed only when section 3 is used in preference to section 4.
VSWR: 33304 and 33305
Frequency range Connector type
SMA Type N 7 mm
DC–8 GHz 1.5 1.45 1.4 
8–12.4 GHz 1.6 1.55 1.5
12.4–18 GHz 1.9 1.8 1.7
Solenoid voltage and nominal coil impedance:
Models Solenoid voltage Coil impedance 
33304B/D 24 to 30 Vdc 262 ohms
33305B/D 0.192 ohms
Power required to switch one section: 3.3 watts. 
(Continuous operation of solenoids requires 10 watts dissipation in heat sink.) 
Environmental 
Temperature, non-operating: –40° C to +85° C. 
Temperature, operating: –20° C to 55° C.  
Altitude, operating: 25,000 ft.  
Vibration, operating: 5 – 500 – 5 Hz, 15 min./cycle, 3 hours/axis. 0.100-inch D.A. to 31 Hz, 
5 g’s to 500 Hz, with and without power applied to the relays in both positions.
Ordering information
See figure 2 for ordering information.
Specifications
www.agilent.com/find/emailupdates
Get the latest information on the products and 
applications you select. 
www.agilent.com
Agilent Technologies’ Test and Measurement 
Support, Services, and Assistance
Agilent Technologies aims to maximize the value you 
receive, while minimizing your risk and problems. We 
strive to ensure that you get the test and measurement 
capabilities you paid for and obtain the support you 
need. Our extensive support resources and services 
can help you choose the right Agilent products for your 
applications and apply them successfully. Every 
instrument and system we sell has a global warranty. 
Two concepts underlie Agilent’s overall support policy: 
“Our Promise” and “Your Advantage.”
Our Promise
Our Promise means your Agilent test and measurement 
equipment will meet its advertised performance 
and functionality. When you are choosing new 
equipment, we will help you with product information, 
including realistic performance specifications and 
practical recommendations from experienced test 
engineers. When you receive your new Agilent 
equipment, we can help verify that it works properly 
and help with initial product operation.
Your Advantage
Your Advantage means that Agilent offers a wide range 
of additional expert test and measurement 
services, which you can purchase according to your 
unique technical and business needs. Solve problems 
efficiently and gain a competitive edge by contracting 
with us for calibration, extra-cost upgrades, out-ofwarranty repairs, and onsite education and training, 
as well as design, system integration, project 
management, and other professional engineering 
services. Experienced Agilent engineers and 
technicians worldwide can help you maximize your 
productivity, optimize the return on investment of your 
Agilent instruments and systems, and obtain 
dependable measurement accuracy for the life of those 
products. 
For more information on Agilent Technologies’ 
products, applications or services, please contact 
your local Agilent office. 
Phone or Fax
United States: Korea:
(tel) 800 829 4444 (tel) (080) 769 0800 
(fax) 800 829 4433 (fax) (080) 769 0900
Canada: Latin America:
(tel) 877 894 4414 (tel) (305) 269 7500 
(fax) 800 746 4866 Taiwan: 
China: (tel) 0800 047 866 
(tel) 800 810 0189 (fax) 0800 286 331 
(fax) 800 820 2816 Other Asia Pacific
Europe: Countries:
(tel) 31 20 547 2111 (tel) (65) 6375 8100 
Japan: (fax) (65) 6755 0042 
(tel) (81) 426 56 7832 Email: tm_ap@agilent.com 
(fax) (81) 426 56 7840
Contacts revised: 09/26/05
The complete list is available at: 
www.agilent.com/find/contactus
Product specifications and descriptions in this 
document subject to change without notice.
© Agilent Technologies, Inc. 2001, 2006 
Printed in USA, July 13, 2006 
5953-2354
Agilent Email Updates