Design of Lowpass Filter With the Wide Stopband Characteristics Using Microstrip Line

Compact Microstrip Lowpass Filter with Wide Stopband and High Attenuation

A compact microstrip lowpass filter using radial stub resonators is developed. This filter is composed of two radial stub resonators that are asymmetrically connected to each other by a stepped impedance structure. This structure results in a very high rejection and wide stopband. The proposed filter with a 3 dB cutoff frequency of 2.07 GHz has been designed, fabricated and measured. Measuremen...

Compact Microstrip Lowpass Filter With Ultra-Wide Stopband Using Patch Resonators and Open Stubs

A compact microstrip lowpass filter with ultra-wide stopband characteristics and high suppression level is presented. To achieve compact size and wide stopband suppression along with improved impedance matching, symmetrically loaded resonant patches, open stubs and stair shaped high impedance stub are introduced in the filter. The measurement results show good agreement with the simulations. Th...

Compact Microstrip Lowpass Filter with Sharp Roll-off and Wide Stopband Using Semicircle Ended Stub Resonator

In this paper, a semicircle ended stub resonator, cascaded to a modified radial patch to design a compact lowpass filter with sharp roll-off and wide stopband is proposed. This filter has 3 dB cutoff frequency at 1.54 GHz. The transition band is only 0.26GHz from 1.54 GHz to 1.8 GHz with corresponding attenuation levels of −3 dB and −20 dB respectively. Maximum insertion loss is 0.1 dB in the p...

Wide Stopband and Sharp Roll-off Microstrip Lowpass Filter using Modified Rhombic Shaped Resonator

Microstrip Lowpass Filters with Reduced Size and Improved Stopband Characteristics

Novel microstrip lowpass filters are developed with reduced size and significantly improved stopband characteristics. After introducing quarter-wavelength open stubs, we get one or two transmission zeros in the stopband. By folding the high impedance microstrip lines, we reduce the size of the filter. Three-pole and five-pole lowpass filters are designed, and their measured frequency responses ...