Dual-Mode Bandpass Filters Using Microstrip Slotted Equilateral Triangular Patch Resonators

Abstract

Two compact and low loss dual-mode filters are proposed by using degenerate modes of slotted triangular microstrip patch resonators. The geometrical size and radiation loss of the triangular patch are reduced simultaneously by loading both horizontal and vertical slots. The resonant frequencies of two degenerate modes can be easily controlled by varying the dimensions and positions of the slots. A two-pole dualmode filter operating at 3.94 GHz with a fractional bandwidth of 4.3% is designed, fabricated, and measured. The measured results verify well the theoretical predictions.

Resonant properties of the Sierpinski‐based fractal resonator and its application on low‐loss miniaturized dual‐mode bandpass filter

“…Insert in Figure 2 is typical equivalent circuit of the patch resonator. The parallel circuit model is represent the resonant mode of the resonator and is coupled in parallel with external source and load [6]. The variable inductance (L) indicates the number of current paths which depends on the resonator with different iteration order.…”

“…However, the insertion loss should be needed to improve using higher quality dual mode resonator structure. In another, some reports have proposed that the fractal-based geometries can enhance the transmission energies [5,6] and thus are used to be designed as antennas or filters. In [7], a microstrip coupled-line BPFs is designed using a Koch fractal shape.…”

“…In [7], a microstrip coupled-line BPFs is designed using a Koch fractal shape. In [8], a microstrip filter with H-shaped fractal pattern is proposed [6]. However, the selectivity is still no good enough to be accepted in common wireless communication system.…”

New microstrip fractal‐shaped square patch resonators filters

“…Some slots have been proposed to reduce the circuit size [4][5][6][7]. Now, some reports have proposed that the fractal-based geometries can enhance the transmission energies [8,9] and thus could be used to design antennas or filters. A microstrip coupled-line band-pass filter is designed using a Koch fractal shape in Ref.…”

“…The printed dipole antenna is well known for its characteristics such as low weight, ease of fabrication and offers relatively wide bandwidths, omnidirectional pattern and a high-polarization purity [1,2]. Many planar printed dipole antennas have been widely studied [1][2][3][4][5][6][7][8][9][10] for radio-frequency identification (RFID) application. The rectangular radiator composed of a 4th-iteration fractal slot, with a pair of 24.7 mm meander patch designed next to the feed line of the antenna.…”