Product Selection Guide - Passive Filters May 2015 High frequency Passive Filters Passive filters from Frequency Devices are available in frequencies up to 1 GHz and in some cases higher in frequency.  The filters are built into a 3.7” by 1.5” case that is 1.25” tall.  The cases are available with or without mounting ears. The following types of filters can be built: Butterworth: Band Reject, Band Pass, High Pass or Low Pass Bessel: Low Pass Gaussian: Low Pass Constant Delay (Linear Phase): Low Pass Chebyshev: Band Reject, Band Pass, High Pass or Low Pass Elliptical (Cauer): Low Pass and High Pass Please contact the Frequency Devices Engineering Department with your filter requirements at 815-434-7800 extension 236.