Zhenqi Kuai

Planar Ultrawideband Antennas With Multiple Notched Bands Based on Etched Slots on the Patch and/or Split Ring Resonators on the Feed Line

Three types of ultrawideband (UWB) antennas with triple notched bands are proposed and investigated for UWB communication applications. The proposed antennas consist of a planar circular patch monopole UWB antenna and multiple etched slots on the patch and/or split ring resonators (SRRs) coupled to the feed line. Good agreement is achieved between the simulated and measured results. These techniques are significant for designing UWB antennas with multiple narrow frequency notched bands or for designing multiband antennas.

Half-Mode Substrate Integrated Waveguide (HMSIW) Leaky-Wave Antenna for Millimeter-Wave Applications

A novel leaky-wave antenna is demonstrated and developed at Ka-band in this work based on the newly proposed half-mode substrate integrated waveguide (HWSIW). This antenna is accurately simulated by using a full-wave electromagnetic simulator and then fabricated through a single-layer printed circuit board (PCB) process. Wide bandwidth and a quasi-omnidirectional radiation pattern are obtained. The proposed antenna is therefore a good candidate for millimeter-wave applications. Measured results are in good agreement with simulated results.

A Multibeam Antenna Based on Substrate Integrated Waveguide Technology for MIMO Wireless Communications

A 24-beams slot array antenna, which achieves 360-degrees coverage over azimuth direction, based on substrate integrated waveguide (SIW) technology is designed, fabricated and measured for supporting the concept of triangle cell, beam diversity and multiple input multiple output (MIMO) wireless communications. Constructed by six 4-beams single layer SIW antennas which integrate the 4times8 modified Butler matrix with a low side lobe level (SLL) amplitude distribution, measured SLLs are reduced as low as -14.5 dB for all beams in E-plane. The size of the SIW single layer multibeam antenna is 385 mm times 110 mm including feeding network. The usable bandwidth of the proposed antenna is 3.75% at 16 GHz.

Substrate Integrated Waveguide (SIW) Monopulse Slot Antenna Array

A Ka-band compact single layer substrate integrated waveguide monopulse slot array antenna for the application of monopulse tracking system is designed, fabricated and measured. The feeding network as well as the monopulse comparator and the subarrays is integrated on the same dielectric with the size of 140 mmtimes130 mm. The bandwidth ( S11 < -10 dB) of the antenna is 7.39% with an operating frequency range of 30.80 GHz-33.14 GHz. The maximum gain at 31.5 GHz is 18.74 dB and the maximum null depth is -46.3 dB. The sum- and difference patterns of three planes: H-plane, E-plane and diagonal plane are measured and presented.

A Substrate Integrated Waveguide Circular Polarized Slot Radiator and Its Linear Array

A top-wall substrate integrated waveguide (SIW) slot radiator for generating circular polarized (CP) field is proposed and characterized in this letter. The reflection of the slot radiator is extremely weak, which simplifies the linear traveling wave array design. Based on such a structure, a 16-element CP SIW traveling wave antenna array is designed, fabricated, and measured at 16 GHz. A -23 dB side lobe level (SLL) with an axial ratio (AR) of 1.95 dB is experimentally achieved. The size of the proposed SIW CP linear array antenna is 285 mm times 22 mm. The measured gain is 18.9 dB, and the usable bandwidth is 2.5%.

Ultrawideband Printed Log-Periodic Dipole Antenna With Multiple Notched Bands

A printed log-periodic dipole antenna (PLPDA) with multiple notched bands is proposed for ultrawideband (UWB) applications. The impedance bandwidth of 3.1 GHz-10.6 GHz with VSWR less than 2 is achieved based on the wideband property of the PLPDA as well as the half mode substrate integrated waveguide (HMSIW) Balun. Different from omnidirectional UWB antennas, the end-fire radiation pattern of the PLPDA is more stable within the UWB band. Multiple notched bands are generated by integrating U-shaped slots into the PLPDA for blocking the interference from other narrow band wireless communication systems. Several antennas with the notched frequencies of 3.5 GHz, 5.5 GHz, 6.8 GHz, and 8.5 GHz are designed, fabricated, and measured. The measured results are in agreement with the predicted results.

A Double Layer Substrate Integrated Waveguide Blass Matrix for Beamforming Applications

In this letter, a double layer Blass matrix based on substrate integrated waveguide (SIW) technology is proposed. A prototype of 4 times 16 Blass matrix is implemented, fabricated and measured with SIW slot antennas installed at the output ports. The measured data are in good agreement with the simulated results. At 16.1 GHz, the measured Side Lobe Level of all individual beams is less than -12 dB. Compared with the conventional waveguide construction, this type of Blass matrix possesses the properties of lower cost, easier fabrication and low profile.

Ku-Band Linearly Polarized Omnidirectional Planar Filtenna

A linearly polarized omnidirectional planar filtenna at Ku-band is presented in this letter. It is a seamless and incorporate design of an inductive window bandpass filter and a planar coaxial collinear (COCO) radiation element. The radiation element has a linearly polarized omnidirectional radiation characteristic. The substrate integrated waveguide filter is used for RF channel selection as well as a balun. The proposed filtenna has merits of light weight, compact size, low cost, and easy integration with other planar circuits. Simulation and measurement results show that the radiation characteristics of the filtenna keep nearly no change within the working band, while unwanted signals at out-band can be effectively filtered.

A compact multiple bands notched UWB antenna by loading SIR and SRR on the feed line

In this paper, a new compact circular monopole ultrawide band (UWB) antenna with multiple narrow bands notched is proposed, designed and fabricated with a standard printed circuit board (PCB) process, which is implemented by loading a stepped impedance resonator (SIR) and a split ring resonator (SRR) on the feed line. Good agreement between simulations and measurements is achieved, which shows the antenna is a promising candidate for UWB applications.

Multiband Antennas Comprising Multiple Frame-Printed Dipoles

In this communication, the design of a multiband antenna consisting of a set of printed frame dipoles is proposed. The frame dipoles of different sizes are nested within each other and are employed as resonators to produce a multiband response. The dual-band antenna operating at 2.4/3.5 GHz is realized by a primary frame dipole having a nested smaller frame dipole. The triband antenna operating at 1.8/2.4/3.5 GHz is composed of three frame dipoles nested within each other. The experimental results show stable radiation patterns similar to those of the traditional strip dipole. The gain of the dual-band antenna is 1.77 dBi at 2.4 GHz and 2.17 dBi at 3.5 GHz, and the gain of the triband antenna is 1.72 dBi at 1.8 GHz, 1.53 dBi at 2.4 GHz, and 1.41 dBi at 3.5 GHz.