High-gain Resonant Cavity Antenna Research Articles

Dual‐polarized high gain resonant cavity antenna for radio frequency energy harvesting

A Fabry pérot antenna with a multilayer superstrate having nonuniform unit cells has been investigated as a receiving antenna for radio frequency (RF) energy harvesting applications. Here, the primary radiator is selected as a dual-polarized aperture coupled microstrip antenna with a double-layer superstrate. This antenna excites orthogonal polarizations, vertical (V) and horizontal (H) in the frequency band of 6.2 and 5.8 GHz, respectively, due to the presence of two orthogonal H-shaped slots in its ground plane. The proposed antenna provides a gain enhancement of 9.8 and 10.1 dBi at the respective frequencies. The rectifying circuit is designed for a frequency of 5.8 GHz using a voltage doubler topology. The circuit provides a power conversion efficiency of 41% at 0 dBm input power.

Single-Dielectric Wideband Partially Reflecting Surface With Variable Reflection Components for Realization of a Compact High-Gain Resonant Cavity Antenna

This communication presents a design methodology for a compact low-cost partially reflecting surface (PRS) for a wideband high-gain resonant cavity antenna (RCA) which requires only a single commercial dielectric slab. The PRS has one nonuniform double-sided printed dielectric, which exhibits a negative transverse-reflection magnitude gradient and, at the same time, a progressive reflection phase gradient over frequency. In addition, a partially shielded cavity is proposed as a method to optimize the directivity bandwidth and the peak directivity of RCAs. A prototype of the PRS was fabricated and tested with a partially shielded cavity, showing good agreement between the predicted and measured results. The measured peak directivity of the antenna is 16.2 dBi at 11.4 GHz with a 3 dB bandwidth of 22%. The measured peak gain and 3 dB gain bandwidth are 15.75 dBi and 21.5%, respectively. The PRS has a radius of 29.25 mm ( $1.1\lambda _{0}$ ) with a thickness of 1.52 mm ( $0.12\lambda _{g}$ ), and the overall height of the antenna is $0.6\lambda _{0} $ , where $\lambda _{0}$ and $\lambda _{g}$ are the free-space and guided wavelengths at the center frequency of 11.4 GHz.

Compact High Gain Resonant Cavity Antenna With via Hole Feed Patch and Hybrid Parasitic Ring Superstrate

A compact and high gain resonant cavity antenna (RCA) is investigated in this work. At first, a ray-tracing model and the full-wave analysis are presented to clarify the characteristics of RCA in cases of finite lateral size and inhomogeneous superstrate. In consequence, a novel compact, high gain, and wideband RCA is proposed. The RCA consists of a via hole feed patch and an array of hybrid parasitic rings fabricated on a superstrate. The via holes feed patch with a high radiation directivity significantly enhances the RCA’s gain. On another hand, the dimension and bandwidth of the RCA are improved by the hybrid parasitic ring superstrate which is constituted by non-periodic parasitic patch and rings. Finally, a prototype of the RCA is fabricated and measured. With only the dimension of $1.35\lambda _{0}\times 1.35\lambda _{0}\times 0.63\lambda _{0}$ , the peak gain of 15.8 dBi and 3 dB gain bandwidth of 10.7% are obtained.

Wideband high‐gain millimetre/submillimetre wave antenna using additive manufacturing

This study presents a novel design of a wideband high-gain resonant cavity antenna (RCA) for millimetre and submillimetre wave bands, and its fabrication using additive manufacturing (AM). The proposed RCA antenna consists of a partially reflecting surface and three impedance matching layers fed by a waveguide. AM techniques are utilised to fabricate the design operating at 30 GHz. Two fabrication techniques are assessed for printing the antenna. The first technique is based on printing a dielectric material and fully coating the parts with a metallic layer, while the second technique involves printing the parts in a single process using metal three-dimensional printing. The first technique offers a lightweight solution while the second technique can print the whole model in one run. The antenna design is investigated by both simulations and experiments. The measured results show a 3 dB gain bandwidth of about 10%, and high gain over 15 dBi for all the three resulting antennas. Good agreement between simulation and measurement is obtained. The antenna is of low cost and achieved good performance in terms of wide bandwidth and high gain, thus it is potentially useful for high-speed wireless communications at millimetre-wave and sub-millimetre-wave frequencies.

A Dual-Band High-Gain Resonant Cavity Antenna with a Single Layer Superstrate

In this communication, we present a novel design of a dual-band high-gain resonant cavity antenna (RCA) with single polarization. First of all, the theory of dual-frequency operation of conventional RCA with single superstrate is discussed. Next, we designed a feed system, for dual-band operation with single polarization and directional patterns, two T-shape slots in nonradiating edges of the microstrip patch are introduced, which serves as the feed system of the designed dual-band high-gain RCA. Then, a full-wave analysis is performed to extract the impedance matching and radiation patterns of feed system and the complete RCA. At the last, measurement results are provided to compare with the modeling and simulations results which agree reasonably well.

High Gain Resonant Cavity Antenna with Meta-material Inspired Superstrate

Abstract A high gain planar Resonant Cavity Antenna (RCA) inspired by metamaterial superstrate is proposed operating at C-band. The RCA is modelled using simple ray tracing method. The unit cell metamaterial consists of Artificial Magnetic Conductor (AMC) and square patch laminated on either side of magneto-dielectric material, is used as the superstrate to design RCA. Square patch is capacitive type and that AMC as inductive. Effects of the reflection phase of the substrate decides the gain of the antenna. A cylindrical dielectric resonator antenna (CDRA) has been used as the primary radiator. The metamaterial unit cell structure is characterized and its effective material parameters are extracted through its S-parameters simulation. The proposed antenna achieves 12.5dBi gain with only 2x2 array superstrate.The results of upto 12 x 12 array superstrate with multiple layers can be demonstrated for higher gain over wide frequency range.

Dual-band high-gain resonant cavity antenna with orthogonal polarisation using slotted patch partially reflective superstrate

A novel dual-band high-gain resonant cavity antenna (RCA) with orthogonal polarisation is presented. The RCA includes a single-layer single-sided superstrate of printed slotted patches located at a designated height above the ground plane of a microstrip patch antenna. The lower band has a measured gain of 18.06 dBi with the vertical polarisation (V-pol) at 10.25 GHz and the upper band has a gain of 19.41 dBi with horizontal polarisation (H-pol) at 11.05 GHz. The cross-polarisation (X-pol) is better than −26 dB at each band. The two bands are controlled arbitrarily and independently. To demonstrate it, two RCAs have been designed with band separation of 3.95 and 5.75 GHz.

A Dual-Band High-Gain Resonant Cavity Antenna With Orthogonal Polarizations

In this letter, a new study on the theory and the design of a dual-band dual-polarized high-gain resonant cavity antenna (RCA) is presented. The RCA includes two layers of orthogonal dipole arrays each located at a designated height above the ground plane of a microstrip patch antenna. A prototype is fabricated, and the measured results confirm the theory. The measured prototype has a lower-band gain of 19.6 dBi with the vertical polarization (V-pol) at 10 GHz and the upper band gain of 18 dBi with horizontal polarization (H-pol) at 11.6 GHz. The cross polarization (Xpol) is better than -27 dB at each band. It is demonstrated that the separation between the two bands is controlled arbitrarily.

High-gain subwavelength resonant cavity antennas based on metamaterial ground planes

Planar metamaterial surfaces with negative reflection phase values are proposed as ground planes in a high-gain resonant cavity antenna configuration. The antenna is formed by the metamaterial ground plane (MGP) and a superimposed metallodielectric electromagnetic band gap (MEBG) array that acts as a partially reflective surface (PRS). A single dipole positioned between the PRS and the ground is utilised as the excitation. Ray analysis is employed to describe the functioning of the antennas and to qualitatively predict the effect of the MGP on the antenna performance. By employing MGPs with negative reflection phase values, the planar antenna profile is reduced to subwavelength values (less than λ/6) whilst maintaining high directivity. Full-wave simulations have been carried out with commercially available software (Microstripes™). The effect of the finite PRS size on the antenna radiation performance (directivity and sidelobe level) is studied. A prototype has been fabricated and tested experimentally in order to validate the predictions.