Interdigital filters is a version of a Cavity filter that uses resonators oriented like interlocking “fingers” to allow for parallel coupling. Interdigital filters are fairly compact, while providing excellent performance. The difficulty with these types of filters depend on the manufacturing tolerances, and the accuracy in which the physical part can be fabricated.

Bree Engineering’s part number 803932 is an interdigital bandpass filter that has extremely low insertion loss across the passband. The percent bandwidth for this particular interdigital bandpass filter is 54%. This ratio allows for an optimal environment for the filter to perform and meet the customer specifications. The insertion loss specification was targeted to be less than 2 dB but the actual performance of the filter was less than 0.75 dB. The rejection points also exceeded the specifications by about 4-5 dB consistently.

As with all of our Filters here at Bree Engineering the design is custom and tailored to the specifications of our clients. We are always striving to do our best to design, build and tune filters of any type.

Please see the attached Filter Test Data for the performance of the filter.

Package Size: 2.65 x 0.85 x 0.60 Inches

Configuration: SMA

Insertion Loss:

<2.0 dBa at Center Frequency 7055 MHz

Return Loss:

>10 dB 5150 – 8960 MHz

Rejection:

>60 dBc DC – 4125 MHz

>60 dBc 10200 – 13000 MHz

Outline Drawing.pdf