Lowpass, Feed-Through, C-Circuit Filters Suppress Broadband Radio Frequency Interference

TTE Filters, a designer and manufacturer of RF and microwave filters for high performance applications announces that its Instec Filters brand ML61 EMI/RFI filters are now qualified to the US Department of Defense DLA Land and Maritime’s MIL-PRF-28861 military standard. This series will be featured at the 2021 International Microwave Symposium in Atlanta on June 8-9, booth #1129.

This series can now be used in military electronic systems to suppress and reduce broadband radio frequency interference which would otherwise compromise system performance. These high performance systems are utilized in military communication devices, oscillators, attenuators and low noise amplifiers.  

The electrical characteristic ranges of these low pass, feed-through, C-circuit, solder-in ML61 filters include Rated Voltage from 50Vdc to 200Vdc, Capacitance from 10pF to 15,000pF and Minimum Insertion Loss from 3dB to 60dB. The Operating Temperature is -55°C to +125°C. Refer to the table below for part-specific details.

The parts in this ML61 series are hermetically glass sealed at one end and epoxied at the other end, with the location of the glass seal dependent on the particular configuration. In conformance with the MilSpec, the company can provide these filters in Configuration A (ML610) or Configuration B (ML611). Please refer to the MIL-PRF-28861/12H standard for more information. The main body of each part in this series measures 0.128in. (3.25mm) in diameter while the main body height is 0.110in. (2.79mm) and the overall tip-to-tip length is 0.625in. (15.88mm). More technical information is provided in the ML61 datasheet at TTE’s website.

Electrical Characteristics for Instec ML61 per MIL-PRF-28861/12H Military Dash Number*

Military Dash Number Instec Part Number Part Configuration (per MilSpec) Rated Voltage (Vdc) Capacitance (pF) Capacitance (pF)
Chebyshev Lowpass Filter
Chebyshev Highpass Filter
Frequency Range
1MHz to 7GHz
1MHz to 7GHz
Passband to Stopband
-50dBc at 1.90 fo
-60dBc at 1.27 fo
-50dBc at 0.84 fo
-60dBc at 0.78 fo
Performance Comparison
"Brick Wall" performance similar to Anti-Aliasing Elliptical Function Filter
"Brick Wall" performance similar to Anti-Ailiasing Elliptical Function Filter
Cases Available
Standard to Custom
Standard to Custom

The MilSpec qualification – specifically MIL-PRF-28861/12H Class B – required rigorous electrical, thermal and mechanical testing including solderability, moisture resistance, solvent resistance, corrosion resistance, physical shock, thermal shock, vibration and life testing of this series. Testing was performed at the in-house environmental testing lab of sister company, Gowanda Electronics. This lab is Defense Logistics Agency Land and Maritime approved (in support of internal product qualifications).

TTE welcomes inquiries regarding the upscreening of additional filters for applications in defense, military and space communities. The company also supports custom designs with extensive experience, proprietary manufacturing equipment, prototyping capabilities and testing facilities.

The ML61 series is manufactured, marked and sold under the Instec Filters name; Instec is now part of TTE.

For technical assistance, part pricing or other information please contact TTE at +1-716-532-2234 or sales@tte.com.


Please refer to series datasheets for the most up to date information in case any data has changed since the news release issued.



More Posts

* indicates required

Subscribe to our Newsletter!