A Dual-Band Circularly Polarized Elliptical Patch Reflectarray Antenna for High-Power Microwave Applications

Abstract

The demand for multi-band high-power antennas, which have been rarely reported, becomes urgent in high-power microwave field. To meet the demand, a C/X dual-band high-power circularly polarized patch reflectarray antenna is proposed in this paper. Two main technologies are adopted to make the proposed antenna realize the high-power feature. Firstly, the elliptical patch with no abrupt structure is proposed to be the dual-band reflecting element to mitigate the electric field concentration. Secondly, the elliptical patches are proposed to be embedded into substrate to avoid the triple junction. The proposed dual-band reflecting element is designed by arranging two embedded elliptical patches with different sizes in a square lattice grid. The larger elliptical patch operates in C-band and the smaller one works in X-band. The elliptical patches are proposed to be rotated to realize continuous 360 o phase response in both bands. By optimizing the thickness of substrate, the element spacing, and the size of the patches, the dual-band element shows good reflection amplitude and phase response and low mutual coupling performance. An antenna prototype with the aperture size of 345 mm × 345 mm is simulated and measured. The measured radiation results of the designed reflectarray antenna are in good agreement with simulations in both C-band and X-band. The measured gain of the antenna at 6.2 GHz is 24.6 dBi, and at 9.3 GHz is 27.8 dBi. Fullwave simulations show that the power capacity of the antenna at 6.2 GHz is about 10.2 MW, and at 9.3 GHz is about 3.9 MW in air condition. The low mutual coupling performance of the proposed antenna is verified both in element level and array level. All of the results show that the proposed antenna has the merits of high-power capacity, dual-band, and low mutual coupling.

Experimental Investigation of Reflectarray Antennas for High-Power Microwave Applications

“…In order to explore the performance of two RA elements in HPMs, the power capacity level of the elements should be evaluated. The power handling capacity of the RA element is calculated by the following equation [ 13 , 21 ]: where P C is the power handling capacity, E b is the breakdown threshold value, E max is the maximum electric field strength of the RA element, and P in is the input power (the value is usually 1 W in HFSS). For the RA element based on resonance phase modulation, the maximum electric field strength is typically observed at the resonance point.…”

“…It can be clearly seen that the maximum electric field strengths of two RA elements are 0.28 × 10 5 V/m and 0.1565 × 10 4 V/m, respectively. It should be noted that the breakdown threshold in air is 3 MV/m [ 13 , 21 , 22 , 23 , 24 ]. Consequently, applying Equation (1), the theoretical power capacity and power density of RA element I can be calculated as 11.48 KW and 7.17 MW/m 2 .…”

“…The limited power capacity of RAs has hindered their effective application in the field of HPM, despite being extensively researched. For example, an investigation was carried out on a dual-band RA based on elliptical patches for HPM applications [ 13 ]. Full-wave simulation results revealed that the RA has a power capacity of 10.2 MW and 3.9 MW at 6.2 GHz and 9.3 GHz, respectively.…”

Design of a Single-layer C/X Dual-band Reflectarray Antenna with Low Cross-polarization

“…Moreover, the overall profile of the antenna is also doubled. The other is to implement dual-band elements on a single-layer substrate [12][13][14][15]. This technique not only possesses the low-profile advantage of the traditional reflectarray antenna but also eliminates the shielding effect.…”

Linearly Polarized Millimeter Wave Reflectarray with Mutual Coupling Optimization

“…In modern days, the reflectarray antenna has developed to such an extent that it is considered suitable for applications such as in 5G and 6G communication systems [2][3][4][5][6]. Recently, researchers have also investigated the possibilities of using the reflectarray antennas in other advanced applications such as snow mass measurements [7], In-band full-duplex applications [8], near meta steering systems [9] and other high power microwave applications [10]. All these applications need the reflectarray antenna to provide optimum performance in terms of losses, phase distribution, mutual coupling, polarization, gain, beamwidth and other performance parameters.…”