Harmonic-Rejection Compact Bandpass Filter Using Defected Ground Structure for GPS Application

Abstract

A miniaturized bandpass filter (BPF) using defected ground structure (DGS) resonator with the characteristic of harmonic rejection is developed in this paper. The second and third harmonics of the proposed BPF are rejected by the characteristic of stepped-impedance DGS resonator. Moreover, open stubs are established so that two adjustable transmission zeros can independently be created to extend the stopband and improve the rejection level. Finally, a second-order BPF, centered at 1.62 GHz with a stopband extended up to 5.6 GHz and a rejection level better than 20 dB, is designed and implemented for GPS application. A good agreement between simulation and measurement verifies the validity of this design methodology.

A method for rejecting 3k‐th harmonics in bandpass 6N‐path filters

“…where g m1 and g m2 are the transconductances of M 1,3 and M 2,4 , respectively, and r o1 and r o2 are the corresponding output resistances of the transistors. Assuming a large R F value, (15) can be simplified as…”

“…For even and odd harmonics suppression in transmission line BPFs, innovative approaches have been presented in several studies . Thanks to differential implementation in ‐path filters, harmonic selectivity around even harmonics is no longer an issue.…”

“…For even and odd harmonics suppression in transmission line BPFs, innovative approaches have been presented in several studies. [15][16][17] Thanks to differential implementation in N-path filters, 2,3,6 harmonic selectivity around even harmonics is no longer an issue. However, suppressing odd harmonics is more challenging, and the attention has been mainly on rejecting the strongest odd harmonics 18 and in particular the third and the fifth harmonics.…”

A Novel Compact Size Wilkinson Power Divider With Two Transmission Zeros for Enhanced Harmonics Suppression

“…The technique of Defected Ground Structure (DGS), in [3,4], depends on band stop characteristics, and it is easier than electromagnetic band gap in fabrication and equivalent circuit modelling, but its structure dimensions need design formulae, and their proper values are obtained iteratively. In addition, it needs backside etching.…”

Design of a Novel Ultrawide Stopband Lowpass Filter Using a DMS-DGS Technique for Radar Applications

“…Due to their improved performance characteristics, many filter techniques and methodologies have been proposed and successfully realized. Defected ground structures (DGSs) with and without periodic array have been realized by etching a pattern in the backside of the metallic ground plane to obtain the stopband effect [1][2][3][4][5][6][7][8][9][10][11][12][13]. DGS often consisted of two large defected areas and a narrow connecting slot channel, which corresponds to its equivalent L-C elements [14].…”