Half-Elliptical Resonator Lowpass Filter with a Wide Stopband for Low Band 5G Communication Systems

Abstract

In this paper, a lowpass filter is designed using half elliptical resonators with a wide stopband. New formulas are presented to achieve a circuit model for the half elliptical resonators used in this work. Additionally, the transfer function and transmission zero equations are used to adjust the frequency of the transmission zeros of the filter. The cut-off frequency of the lowpass filter is 1.26 GHz with a sufficiently large stopband, extending from 1.48 GHz to 20 GHz. The proposed filter’s figure of merit is 62,520, demonstrating its outperformance compared to the state of the art. The filter is implemented on a RT-5880 substrate with a constant dielectric of 2.2, thickness of 31 mil and loss tangent of 0.0009. The LPF was fabricated and tested, showing good agreement between the simulated and measured results.

Design of a Compact Quad-Channel Microstrip Diplexer for L and S Band Applications

“…Different kinds of resonators are also used for the performance improvement of the frequency response [ 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 ]. Different shapes of the resonators have been recently presented, such as U-shaped [ 26 ], T-shaped [ 27 ], Pi-shaped, [ 28 ] stepped-impedance [ 29 ], and patch resonators [ 30 , 31 ].…”

A Compact Microwave Quadrature Hybrid Coupler Using Capacitive Composite Lines and Meandered Stubs

“…In addition, other types of resonators, such as spiral ring resonators [13], half-wave resonator [14], split ring resonators [15][16][17] and metamaterial resonators [18] have been used to improve the QHCs performances. Different kinds of resonators have also been applied in other microwave devices like diplexers [19][20][21], filters [22][23][24][25][26][27][28][29], sensors [30,31] and dividers to provide compact size, harmonics suppression and performance improvement.…”