A coplanar waveguide fed wideband dipole antenna using a multiplemode resonator is proposed and developed. A simple dipole antenna structure is investigated for its wideband radiation performance by virtue of its single, double, triple and quadruplet resonant modes. Later, a metallic reflector is properly installed in order to provide a unidirectional radiation pattern as demanded for the long-term evolution (LTE) application. In the design, a quadruplet-mode wideband dipole antenna is explored to cover the LTE operation band with a 10 dB fractional bandwidth of 46.8%. Finally, an antenna prototype is fabricated and tested to experimentally verify the expected wideband property and predicted results.

Abstract-An ultra-wideband (UWB) bandpass filter (BPF) with hybrid coplanar waveguide (CPW)/microstrip structure is introduced in this paper. Then a pair of lowpass filters is integrated on the CPW feed lines to achieve a good out-of-band rejection. At last, a notched band with two transmission zeros is realized at 5.8 GHz by using a symmetric E-shaped slot-line and etching slots on microstrip resonator. Two transmission zeros are realized in the desired notched band, and out-of band rejection is more than 32 dB. In order to prove the validity, the proposed filter is fabricated and measured, and the measured results are in good agreement with simulated ones.

Abstract-This paper proposes a method to design an even-order symmetric bandpass filter with Chebyshev response. The alternative J inverters and λ/4 short-ended resonators are used in the filter design. It is well known that a conventional even-order Chebyshev bandpass filter prototype can be designed by using Jinverters. However, to achieve the Chebyshev response, a problem is that the output admittance Y L is unequal to the input admittance Y 0 since normalized g n+1 is not equal to the g 0 . Thus, for the symmetrical structure, an additional impedance transform can be installed at the output port to solve this problem, thus the network of even-order symmetric bandpass filter with a Chebyshev response should be modified with new J-inverters. In this work, all J-inverters of the symmetric bandpass filter with Chebyshev response are extracted and described as curves to determine the circuit dimensions of the proposed structure. Two even-order Chebyshev bandpass filters with the second-and fourth-order are designed with the proposed method as its application examples. Finally, the fourthorder filter is fabricated and measured at center frequency of 2.5 GHz with the fractional bandwidth 25%. The measured result is in good agreement with the simulated one.

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