Custom EMI Filter Design Capabilities by Captor Corporation
At Captor Corp., we are the experts in electromagnetic interference. We custom design EMI filter solutions to meet the exact specifications of your application, usually more cost effectively than most competitors’ catalog items. With more than 10,000 designs completed to date, we have the proven capability of delivering high reliability electromagnetic, power line, signal line, and TEMPEST filters for military, aerospace, commercial, and industrial applications.
In any chassis configuration imaginable, and with a choice of multiple termination interfaces, we build standard filter solutions rated 0-400 VDC, 0-480 VAC, 0-400 A, and DC-400 Hz, with higher voltages, currents, and frequencies readily available on request. Our services include filter circuit design and analysis, packaging design and layout, and quick turnaround prototyping.
Our engineering support extends from project inception to completion, and includes extensive qualification, environmental, and acceptance test procedures to ensure all filters meet applicable specifications.
To learn more about our custom EMI filter solutions, read below, or contact us today to discuss how we can help you with your application.
What is EMI?
To better understand the importance of EMI filters, it is important to understand what EMI is and the types of EMI that Captor filters are designed to eliminate. Simply put, EMI (electromagnetic interference) is any noise or electrical signal that has the potential to cause the disruption of an electrical signal. The effects of EMI may present themselves as something innocuous as static heard in a radio transmission, to something as serious as a weapon systems malfunction. There are many types of EMI that require different filtering solutions. Knowing what they are simplifies the process of source identification.
Conducted EMI is interference flowing through any conductor or wire; in this type of EMI, the interference is caused by physical contact of conductors or wires.
Common Mode EMI is typically associated with higher frequencies; in this type of EMI, the interference will flow in the same direction across a single or many conductors.
Differential EMI is mostly found in lower frequencies; this type of interference is the result of one affected conductor coupling EMI to adjacent conductors. It can flow in opposite directions, which may cause signals to cancel each other out.
Radiated EMI, as its name implies, is transmitted; these magnetic or electrical fields flow through the air much like radio waves from an antenna. They are the most common form of EMI and created by virtually any electronic or electrical device.
The pervasive nature of EMI cannot be understated; that’s why proper filtering is critical as EMI can originate from multiple sources. This is a short list of possible EMI sources that can benefit from filtering:
- Power supplies
- Ignition systems
- Voltage regulators
- Switches, relays
- Power transmission lines
- Computing devices
- Battery chargers
Custom EMI Filter Design Capabilities
Build to Print
Research and Development
Insertion Loss / Attenuation
0 to 100 dB
0 to 400 VDC
0 to 480 VAC
Higher Voltage rating available upon request
0 to 400 Amps
Higher Currents available upon request
DC to 400 Hz
Other frequencies available upon request
Typical Operating Temperature
-55 to +71 °C
Typical Storage Temperature
-55 to +105 °C
CRS, Brass, Aluminum, Stainless Steel
Secondary Operations (In-House)
Quick Turn Prototypes
Prototype to Large Scale Production Runs
Typical Lead Times
1 week (Stock)
10 to 12 weeks (Custom)
1 to 3 weeks (Prototypes)
AS9100 Rev C
PCAD (Circuit Boards)