Fei Xue

A High-Efficiency Transmitarray Antenna Using Double Split Ring Slot Elements

This letter present a high-efficiency transmitarray antenna using a four-layer double split ring slot structure as the unit cell element. The transmission coefficient of the element at different incident angles is analyzed by Ansoft HFSS, and the results show that the element has the advantages of low transmission loss and less sensitivity to the incidence angle of the electric field. A high-efficiency transmitarray antenna composed of four layers of double split ring slot elements is designed, manufactured, and tested at Ku-band. The diameter of the transmitarray antenna is 6.76 wavelengths, and the measured gain is 23.9 dB. Radiation efficiency of 77.6% and aperture efficiency of 55% are achieved at a center frequency of 13.58 GHz in this design. The measured 1-dB and 3-dB gain bandwidths are 7.4% and 17.7%, respectively.

Design of X/Ku Dual-Band Dual-Linear Polarization Reflectarray Using Double Parallel Dipole Elements

Two single-layer X/Ku dual-band dual-polarization reflectarray antennas of different sizes with double parallel dipole elements are presented. Elements of the two bands are set to two orthogonal linear polarizations and placed in interlaced grid. The proposed reflectarrays operate in two frequency- bands within X-band centered at 10 GHz and Ku-band centered at 13.58 GHz. The smaller size reflectarray with elements arranged in a 13 × 13 grid for X-band and in a 12 × 12 grid for Ku- band is designed and simulated first. Based on the excellent dual-band performance of the small size reflectarray, then a larger size prototype has been designed, manufactured and measured. Measured results demonstrate the maximum gain of 28.54 dB with 50.93% aperture efficiency at 10 GHz and 31.06 dB with 51.34% aperture efficiency at 13.58 GHz, which show desirable dual-band dual-polarization radiation performance.

A novel single-layer reflectarray antenna using square spiral element

A novel single-layer reflectarray using square spirals is presented in this paper. The square spiral element employs four square spiral arms. By changing the length of the arm, a 450° phase variation range is realized. Besides, the element indicates stable responses for different incidence angles and the reflection phase curve is almost linear. Based on the good phase performance, a square reflectarray with side length of 99 mm is designed and simulated. The simulation results show good radiation performances and 1-dB gain bandwidth is about 31.3% at the center frequency of 15 GHz.

A novel seamless scanning leaky wave antenna in ridge gap waveguide technology

A novel seamless scanning leaky wave antenna in ridge gap waveguide technology is presented. The impedance matching technique is employed to suppress the open-stopband (OSB) which produces a discontinuity for a seamless scanning leaky wave antenna. Ridge gap waveguide proposed recently is used as the feeding structure. The antenna radiates from longitudinal slots of which the leaky constant is designed small to ensure a high directivity. The simulation results of full-wave analysis show that the proposed antenna bandwidth is from 12GHz to 18GHz covering the whole Ku-band while seamless scanning is achieved from backward to forward directions including broadside radiation. The scanning range is from −20° to 14° with an average gain of 18dB.

A new single-layer reflectarray using circular patch with semicircular ring slots

A single-layer reflectarray antenna using circular patch with four semicircular ring slots is proposed in this paper. By changing the diameter of the circular patch, the proposed phasing element can realize phase range about 500 degrees with relatively stable reflection magnitude. Besides, the reflection phase curve with smooth slope is almost linear. Based on the good phase response, a 421element reflectarray is designed, simulated and fabricated. The measured results show that 1.5-dB gain bandwidth can attain 24% at the center frequency of 15 GHz.

Design of a novel Ku/X-band reflectarray/transmit-array antenna with frequency selective surface

A planar reflectarray/transmitarray antenna which reflects/transmits the incident fields radiating from feed antenna is presented. The antenna works as a reflectarray at 13.85 GHz and a transmitarray at 8 GHz. The unit cell is composed of three layers. The first layer consists of a crosseddipole element and a square ring frequency selective surface (FSS) on the top and bottom surfaces of a dielectric substrate. The second and third layers are identical and consist of a square ring slot element on both sides of a dielectric substrate. An air gap is inserted between layers. The aperture of the antenna is 225 mm which equals 10.4 wavelengths at 13.85 GHz and 6 wavelengths at 8 GHz. The reflectarray/transmitarray antenna is fabricated, and NSI planar near-field system is used to measure the performances of the prototype. Good agreement between the simulated and measured results has been achieved. The measured gain is 27.1 dB in reflection mode at 13.85 GHz resulting in a 38% aperture efficiency and 23.1 dB in transmission mode at 8 GHz resulting in a 45.7% aperture efficiency.

Terahertz High-Gain Offset Reflector Antennas Using SiC and CFRP Material

Two high-gain terahertz (THz) offset reflector antennas are proposed. The silicon carbide material and thermally stable carbon fiber-reinforced plastic are selected as reflectors for high specific stiffness and low thermal expansion coefficient which are helpful for space use. Dual polarization is achieved by introducing a wire-grid polarizer which can separate the two THz polarization waves provided by multimode horns fabricated in electroforming technology. Furthermore, three-coordinate test system and theodolites are employed to detect the surface error of dishes and alignment of antenna subsystem. The physical optics analysis based on the measured reflector surface data is introduced referring to the large aperture antenna patterns by virtue of its accuracy and high efficiency. The results of this novel method are compared to that of the near-field test. Measurements show that the sidelobe levels (SLLs) of the single polarization silicon-based reflector are below −32 dB while the gain is 55.3 dB at 330 GHz, and the dual polarization carbon fiber-reinforced plastic reflector antenna suppresses the SLLs to −28 and −29 dB in two principal planes while the gain is 57.2 dB at the same frequency, respectively. The good performances of the proposed antennas indicate the potential for the application of space THz radiometer.

A broadband reflectarray using patch with slot ring on ground plane elements

A broadband center-fed reflectarray antenna is presented in this paper. Patch with slot ring on ground plane elements are used for bandwidth improvement. It is shown that quasi-linear phase responses with broad frequency band can be achieved by such a phasing element. An 11×11 elements reflectarray is designed and simulated. The results show that the simulated gain is 23.92 dB at the center frequency of 13.58 GHz with 3-dB bandwidth of 52%, which demonstrate significant broadband operation compared with that of conventional reflectarray.

A new broadband reflectarray antenna using novel single-layer elements

A novel single-layer reflectarray element for broadband use is proposed. Ansoft HFSS is used to analyze the reflection phase for the element. By varying the element size, a slow slope of the reflection phase curve with the phase range over 600° is achieved. A center-fed 121-element reflectarray antenna is designed using the proposed elements and a linearly polarized pyramidal horn antenna is used as the feed of the reflectarray. The simulated results show that the gain of 24.42dB at the center frequency of 13.58GHz with 3-dB gain bandwidth of 36.8% (from 11.08~16.08GHz), demonstrating a wideband performance compared to the conventional designs.