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This paper proposes a novel single‐feed filtering dielectric resonator antenna (FDRA) using fusion design method and the microstrip‐slot coupled feeding structure. Two pairs of slotlines are elaborately designed and perpendicularly loaded on the coupling slot to provide two radiation nulls at the edges of the passband. Therefore, a compact DRA with a quasi‐elliptic function bandpass response is constructed without extra filter circuits. Furthermore, two radiation nulls can be individually controlled through changing the length of the corresponding slotlines. For proving the effectiveness of the design, a prototype FDRA operation at 3.45 GHz is fabricated and measured. The measured results show that the peak realized gain is 5.84 dBi and the ‐10dB impedance bandwidth is 10.29% (3.29 ‐ 3.65 GHz). The proposed FDRA not only has good performance, but also has simple design. [ABSTRACT FROM AUTHOR]

In this paper, a wideband filtering power divider (FPD) based on dual-composite left–right-handed (D-CRLH) resonator is proposed. The D-CRLH filter unit, featuring a parallel stepped impedance resonator (SIR), is used to replace the λ/4 transmission line of the Wilkinson power divider, which can make the FPD more compact. Due to the inherent characteristics of D-CRLH resonator, two transmission zeros can be generated on both sides of the passband, so the proposed power divider based on the D-CRLH resonator can achieve a quasi-elliptic filtering response. To further enhance anti-interference ability at low frequencies, a pair of open stubs is added to the output feedline to introduce an additional transmission zero on the low-frequency side of the power divider passband. Finally, isolation resistors are introduced on the input and output feedlines to improve the isolation between the output ports. For validation, a prototype with a center frequency of 3.6 GHz is fabricated and measured, with −10 dB fractional bandwidths (FBWs) of 58.3 %(2.55–4.65 GHz). The measurement results are basically consistent with the simulation results, and its isolation in the passband is all more than 13.8 dB. [ABSTRACT FROM AUTHOR]

In this paper, a high-selectivity equal-ripple wideband balanced bandpass filter (BPF) is proposed. Comprising two parallel coupled lines (PCLs) linking the 50-Ohm input and output feedlines, a pair of branch lines connecting the respective differential input and output ports, and a transverse transmission line interconnecting the left and right branch lines within the symmetrical plane SS ', this design configuration yields a bandpass characteristic under differential-mode (DM) excitation, while also inherently achieving bandstop performance under common-mode (CM) excitation. The optimization objective function employs the ideal Chebyshev transfer function to attain equal-ripple DM filtering responses. Additionally, to bolster selectivity, a PCL structure replaces the left branch line, generating additional transmission zeros (TZs) positioned on both sides of the DM passband. For validation, simulation and measurement of an equal-ripple wideband balanced BPF operating at 3.7 GHz demonstrate close agreement between the simulated, measured, and synthesized results. [ABSTRACT FROM AUTHOR]

In this paper, a newly composite right-/left-handed (CRLH) resonator is presented and applied to constitute a compact dual-band balanced bandpass filter (BPF). The proposed CRLH resonator contains two spiral coupled line segments. By imposing the differential-mode (DM) and common-mode (CM) excitation, the DM and CM equivalent circuits of the presented resonator and their lumped-element circuit models are built for investigating the resonant property. The CRLH resonator has two DM resonances and are adopted to design two DM passbands. Also, the CM resonances are all far away from DM resonances, achieved intrinsic desirable CM rejection within DM frequency range without any auxiliary elements. Attributing to the mixed electric and magnetic coupling between two coupled resonators and the introduced source-loaded coupling, multiple transmission zeros are obtained and therefore enhance the selectivity and attenuation in stopband. Finally, a well-designed dual-band balanced BPF is fabricated. Verification of the presented structure and design method's validity is evidenced by the measured results, which are in agreement with the simulations. [ABSTRACT FROM AUTHOR]