Band-pass filter for GHz frequency range - has filter with oscillating dielectric elements and filter with microstrip lines

摘要

The bandpass filter is for a double superhet, receiver working in the GHz range. It comprises a support in which bodies of dielectric material are arranged, at least one mode of vibration of the bodies being at or near the desired pass band and forming a first type of filter. Short circuited microstrip lines whose lambda/2 resonance is in or near the desired pass band form a second type of filter. The two filter types are connected by a line and dimensioned so that the vibration modes of the first filter type are at different frequencies from the lambda/2 resonances corresponding to multiples of fractions of the desired lambda/2 resonance of the second filter stage.