Jiawen Sun

A Novel Planar Switched Parasitic Array Antenna With Steered Conical Pattern

A novel planar switched parasitic array antenna has been proposed for wireless communication. Compared with conventional switched array antennas, this array antenna has more compact planar structure and steered conical elevation pattern. Simulation and measurement have been carried out to validate the design. PIN diodes and micro-controller unit (MCU) are used to implement a beam switching system. Experimental results show that this antenna has the capacity to provide beam switching.

Design of Planar ESPAR Antenna by Using Sidelobe Reduction Algorithm

Planar electronic steering passive array radiator (ESPAR) antenna for wireless mobile terminals is proposed in this paper. To achieve conical elevation pattern and compact size, a modified central grounded hexagonal patch antenna is utilized. A robust sidelobe reduction (SLR) adaptive algorithm is invented to optimize the reactive load for each passive element. Fabrication and measurement have been carried out to validate the advantages of this antenna, experiment results show that the planar ESPAR antenna has good capacity of pattern steering in azimuth, the gains of antenna are better than 7 dBi in three different directing cases, azimuth pattern and elevation pattern at desired direction have been measured and present excellent performances.

Parametric study of a planar switched parasitic array antenna

This paper presents an investigation into the design parameters of a planar switched parasitic array antenna for possible use in wireless communication. This proposed antenna provides multiple radiation patterns by controlling the status of switches. The effect of the central cylindrical metal via radius, the feed location, the hexagonal patch size, the spacing between patch elements, and the ground plane size on the antenna resonant frequency and radiation pattern are studied. It is found that the patch size and the central cylindrical metal via radius can be used as a major means to tune the antenna resonant frequency and good impedance matching can be achieved by adjusting the feed position. Also, the spacing between patch elements and the ground plane size are the key parameters in determining the radiation characteristics.

A novel dielectric-supported switched parasitic antenna array

A novel dielectric-supported switched parasitic antenna array for mobile wireless communications is developed. The antenna array provides multiple radiation patterns with a single RF port without the need for RF switches or phase shifters in the direct RF signal path. The size reduction of the seven-element monopole antenna was accomplished by employing dielectric-supported structure with a relative permittivity around 2.2. Measured results are used to demonstrate the performance improvement

Design and investigation of dielectric resonator antenna oscillator (DRAO) in electronic toll collection (ETC) system

A novel dielectric resonator antenna oscillator (DRAO), which realizes dielectric resonator antenna (DRA) and dielectric resonator oscillator (DRO) simultaneously, is presented in this paper. The design procedure of the parallel-feedback type DRAO at dedicated short range communications band is discussed. Firstly, the DRA was three-dimensional simulated by HFSS. Then the DRO was designed based on the negative resistance theory, using the ADS software for optimization and nonlinear analysis. Finally, it was integrated in the on-board unit (OBU) of electronic toll collection (ETC) system. The experimental results of the OBU show that the performance of the DROA is well and it can be used in real ETC system.

A frequency reconfigurable hexagonal patch antenna with switchable slot

A frequency reconfigurable hexagonal patch antenna with switchable slot is proposed in this paper. By changing the slot status, two resonant frequency bands at 2.29GHz and 2.46GHz respectively can be obtained without special matching network, and the radiation patterns at the two frequency bands are very similar to each other. The simulated and measured results are presented to validate this concept, which could be used for bandwidth enhancement. This proposed antenna is interesting for wideband wireless applications because of its low profile, light weight and easy fabrication.

Design and preliminary analysis of a pattern reconfigurable terminal MIMO antenna for receiving antenna selection

A newly-built broadband MIMO measurement platform in indoor environment is constructed. The platform is designed for measuring the S21 parameter between M transmitters and N receivers (M<;=8, N<;=8), which enables us to analyze the capacity of the radio propagation channel. A pattern reconfigurable antenna for receiving antenna selection at 2.48GHz has been designed and evaluated. Comparisons of MIMO systems employing antennas with different selection schemes are presented. The system performances are discussed in terms of channel capacity.

Effect of inter-element spacing on performance of planar switched parasitic array antenna

The effect of inter-element spacing on performance of planar switched parasitic array antenna is present in this paper. Compared with the conventional planar switched parasitic element playing its role of director in reference, the paper emphasizes the switched parasitic element also act as a reflector to provide beam switching. Thus, the antenna size reduction is achieved. This advantage makes it suitable to incorporate into wireless terminals.

Design of a monopole ESPAR antenna using a novel sidelobe reduction algorithm

A monopole Electronic Steering Passive Array Radiator (ESPAR) antenna for continuous wave RCS measurement is proposed in this paper. A novel robust sidelobe Reduction (SLR) adaptive algorithm is used to optimize the reactive load for each passive element. Simulated results show that the monopole ESPAR antenna has good capacity of pattern steering in azimuth.

Design and investigation of a novel beam-steering cylindrical dielectric resonator antenna

A novel beam-steering cylindrical dielectric resonator antenna (DRA) is presented in this paper. The proposed DRA consists of a cylindrical dielectric resonator with dielectric constant of 80 and two symmetrical microstrip transmission line feeding ports. It is fabricated and mounted on a grounded FR-4 microwave dielectric material. The proposed DRA is analyzed using the high frequency simulation software. The radiation pattern of the beam-steering DRA can be controlled by tuning the phase differences of the two feeding ports. When the phase difference is zero degree, the radiation pattern is directional. On the contrast, the radiation pattern is quasi omnidirectional with the phase difference of 180 degree. The resonant frequency of the DRA is about 5.5GHz, which can be tuned to 5.8GHz easily through adding a metal screw on the back of the dielectric resonator for dedicated short-range communication (DSRC).