Each bandpass decimator comprises an error cancellation filter, a bandpass filter, and a decimator.

Provided is an ultra wideband bandpass filter having a pass band width appropriate as a bandpass filter for UWB.

Provided is a band pass filter having an ultra-wide band and an appropriate pass band width as a band pass filter for UWB.

The duplexer (1) comprises a first band-pass filter and a second band-pass filter with a lower passband than the first band-pass filter.

The constant impedance filter can be implemented as a low pass filter, a high pass filter, or a bandpass filter.

A low-pass filter or all pass filter constructs the network.

The oximeter includes a band pass filter.

An engine ECU 200 includes a bandpass filter (1) (410), a bandpass filter (2) (420), and a bandpass filter (3) (430).

The passband f1 of the lowpass filter circuit, the passband f2 of the bandpass filter circuit, and the passband f3 of the highpass filter are in a relation f1<f2<f3.

The dielectric filter of the present invention is embodied as a low-pass filter, high-pass filter, or band-pass filter.

The bandstop filter is tuned to the first bandpass filter in such a way that it blocks a contiguous wavelength range that partially overlaps with a pass-band width of the bandpass filter.

The band stop filter (3) has a filter bandwidth which is narrower than the band pass filter (4).

The filter can be a long-pass, short-pass, or narrow bandpass filter.

The voltage tunable filter can be one of a low-pass, high-pass, band-pass, or band-stop filter.

No particular bandpass filter is required.