Jiao Yong-chang

The Design of High Gain Dipole Antenna with Metamaterial Cover

In this paper, we analyze a metamaterial cover based on metal wire array, and use it to increase the gain of dipole from 2.15 dB to 14.5 dB, with narrow beam and low side-lobe levels. And then provide the use of metal strips etched by printed circuit board (PCB) process to substitute the metal wires in order to reduce the weight and be easy in processing. The structure of metal strip array can also greatly increase the gain of dipole and possess good practical engineering application.

Effect of random surface errors on radiation characteristics of the side-fed offset Cassegrain antenna

In this paper the average power pattern of the side-fed offset Cassegrain (SFOC) dual reflector antenna is analyzed, and the effect of the random surface error on radiation characteristics of the antenna is introduced. Here, the random surface error is defined as the error of the standard reflector in its normal direction and the errors in a small zone of the reflector are considered as equal. We also assume that the phase error on the aperture led by the random surface error obeys a Gaussian distribution with zero mean, under which the expression of the average power pattern is deduced. Finally, the data related to the radiation characteristics of the antenna are calculated and the corresponding curves are presented. The obtained results can be used for the user to determine the manufacturing accuracy of the reflector of the SFOC antennas.

Frequency response of 1D dispersive sea surface by the ADE-FDTD algorithm

The frequency response of a one-dimensional (1D) sea surface was investigated using the finite-difference time-domain (FDTD) algorithm with pulsed wave excitation. Where the sea water is regarded as an isotropic and dispersive medium, it satisfies the single-pole Debye model. The auxiliary differential equation (ADE) technique is incorporated into the FDTD scheme to deal with the dispersive sea surface. To ensure the feasibility of our present method, the frequency response of dispersive sea surface by the ADE-FDTD method is compared with the result by the conventional method of moments (MOM), which requires an individual calculation for every frequency point of interest. Finally, the scattering characteristic of dispersive sea water is investigated for different wind speed, temperature, and salinity. The representative far zone scattered field versus time is also analyzed.

Design of High Gain Metamaterial Cover Used in the Dipole Antenna

In this paper, we analyze a metamaterial cover based on metal wire array, and use it to increase the gain of a dipole from 2.15 dB to 14.5 dB, with narrow beam and low side-lobe levels. And then provide the use of metal strips etched by printed circuit board (PCB) process to substitute the metal wires in order to reduce the weight and be easy in processing. The structure of metal strip array can also greatly increase the gain of dipole and possess good practical engineering application.

A novel algorithm for correcting probe position errors in planar near-field measurements

A novel algorithm for correcting probe position errors in planar near-field measurements is presented. The basic principle of this algorithm in practical planar near-field antenna measurements is given. Furthermore this algorithm is validated by experiments. The results of experiments prove the correctness, validity and engineering practicability of the algorithm presented in this paper.

Rigorous full-wave analysis of the base-station antennas

Rigorous analysis of the Base-Station (BS) antennas with reflector is made in this letter. The wire-grid modeling of BS antenna is established. In order to improve the solution accuracy and efficiency, some efficient techniques such as three-term sinusoidal interpolation basis function and discrete wavelet transform are used. Numerical examples considered here are the typical vertically polarized and the dual-polarized BS antennas. The calculated results for the vertically polarized BS antenna are in good agreement with the measured data, which show that the analysis modeling used is accurate and reliable.

A new hybrid algorithm for correcting probe position errors in planar near-field measurements

A new hybrid algorithm for correcting probe position errors in planar near-field measurements is presented and computer simulated. The calculation results show that the hybrid algorithm presented in this paper has a fast convergence rate, good numerical stability, high precision of calculation and strong universality and applicability and is an applied and effective method for correcting probe position errors in planar near-field measurements.

Radiation characteristics of airborne spiral antennas

The radiation fields of the Archimedean spiral antenna are derived by approximating the spiral with a series of semicircles. The computational formulae for calculating the radiation fields of the airborne spiral antennas are developed by using geometrical theory of diffraction (GTD). The calculated results are in good agreement with the experimental ones.

Optimal model of combined phase center for horn feeds and its computational method

A definition of combined phase center for horn feeds is given. Formulas ofE-plane andH-plane combined phase center for conical horns and the corresponding optimal model are presented, and a fast optimization method for solving this model is described. By using this method, the phase center of corrugated horn is discussed and calculated, and the variation of the phase center with distance and operating frequency is given.