| 摘要 |
An improved, more compact microwave equalizer is provided by utilizing a length of coaxial transmission line to which at least a pair of relatively small diameter, flexible, coaxial cable resonant stubs are coupled through film type impedance means. Each coaxial cable stub is disposed adjacent the outer conductor of the transmission line, for compactness, and the length of each stub is minimized by use of high dielectric constant material therein. By shortening the length of each resonant stub and by shunting a capacitor across each resonant stub, the frequencies of the upper and lower band edges of the equalizer's attenuation curve are spread apart, while simultaneously providing the desired operating frequency band. Slots and/or an annular recess provided in the relatively thick outer conductor of the transmission line receive the stubs and the retaining apparatus for the film type impedance means. The characteristic impedance of the equalizer is maintained relatively constant throughout its length by providing air dielectric in the region of the structure in the internal diameter of the outer conductor portion associated with said annular recess. The voltage standing wave ratio of the equalizer may be improved by providing a slightly reduced diameter, and a corresponding air gap in the surrounding dielectric material, for a portion of the central series conductor of the transmission line which is located between the coupling points of the stubs.
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