Yunlong Lu

Miniaturized substrate-integrated coaxial line bandpass filter with improved upper stopband

A miniaturized substrate-integrated coaxial line (SICL) bandpass filter with improved upper stopband using asymmetrical spiral stub-loaded resonators is presented in this paper. Owing to the space-filling feature of the spiral structure, the size of the proposed filter is significantly reduced. A theoretical analysis is carried out to examine the resonance property of the proposed resonator. It is found that the frequency ratios of the second and third harmonics to the fundamental frequency can be extended to 2.86 and 4.4. Benefiting from the circuit structure and SICL technology, the designed filter has a small size, wide stopband, low crosstalk, and high-density integration ability. The measured results show that the proposed filter, with dimensions of 0.051λ0 × 0.044λ0, operates at 1.056 GHz and the 20-dB rejection band is extended to 3.94f0.

A novel dual-band bandpass filter with C-section loaded resonators

A novel dual-band bandpass filter with C-section loaded resonators is presented in this paper. The resonance characteristics are simply analyzed by using odd-/even-mode method. Based on the new resonator structure, an experimental dual-band filter is demonstrated with center frequencies of 1.5 and 2.5 GHz. The measured results exhibit good agreement with the full-wave simulation results, validating the proposed design concept.

MM-wave cylindrical lens antenna for maritime high-speed wireless communications

A novel cylindrical lens antenna operating at millimeter-wave (mm-wave) frequencies has been designed for maritime high-speed wireless communications. It is composed of a cylindrical modified Luneberg lens and a planar feed linearly-tapered slot antenna (LTSA). The cylindrical modified Luneberg lens consists of two parallel plates which are partially filled with Polytetrafluoroethylene (Teflon). The lens antenna is designed, fabricated and tested at 30 GHz. Measurements show clean and symmetrical fan-beam patterns. The measured 3-dB E- and H-plane beamwidths are 6.6° and 52.5°, respectively, and the E-plane sidelobe is -19.9 dB. In addition, an impedance bandwidth of 17.3% is observed.