A broadband, contiguous stacked, two-layer, square microstrip patch antenna element design is described which can be used for linear or circular polarization. Single layer microstrip patch theory for the rectangular patch radiator is presented and used as a basis for understanding the two-layer patch configuration. The theory is modified to predict radiation patterns and resonant frequencies of the two-layer microstrip patch antenna element. Experimental results include the radiation patterns, dominant resonant frequencies (TM1 0 mode), return loss (S11 ), and bandwidth for X band elements as a function of dielectric constants, dielectric thicknesses, and patch sizes.

/pdf/design-of-a-two-layer-capacitively-coupled-microstrip-patch-vtip657n5i.pdf

Design of a two-layer, capacitively coupled, microstrip patch antenna element for broadband applications

A low-profile high-directivity, and double-negative (DNG) metamaterial-loaded antenna with a slotted patch is proposed for the 5G application. The radiated slotted arm as a V shape has been extended to provide a low-profile feature with a two-isometric view square patch structure, which accelerates the electromagnetic (EM) resonance. Besides, the tapered patch with two vertically split parabolic horns and the unit cell metamaterial expedite achieve more directive radiation. Two adjacent splits with meta units enhance the surface current to modify the actual electric current, which is induced by a substrate-isolated EM field. As a result, the slotted antenna shows a 7.14 dBi realized gain with 80% radiation efficiency, which is quite significant. The operation bandwidth is 4.27-4.40 GHz, and characteristic impedance approximately remains the same (50 Ω) to give a VSWR (voltage Standing wave ratio) of less than 2, which is ideal for the expected application field. The overall size of the antenna is 60 × 40 × 1.52 mm. Hence, it has potential for future 5G applications, like Internet of Things (IoT), healthcare systems, smart homes, etc.

https://www.mdpi.com/1424-8220/20/11/3323/pdf

Low-Profile Slotted Metamaterial Antenna Based on Bi Slot Microstrip Patch for 5G Application.

The key issue in the design of microstrip reflectarray antennas is the technique used to obtain the required phase shift in the field scattered by each element. Many solutions have been proposed in the past. Stub loaded patches, patches of variable size and patches with variable rotation angles are currently the most popular techniques. This paper introduces a different technique. The approach is based on identical patches with holes of different size to change the resonant frequency. This gives in turn a change in the phase of the reradiated field and allows directing the main lobe of the radiation pattern off broadside. The analysis was carried out at 33.5 GHz, first on a single element and then extended to arrays of finite dimensions. Some arrays were built and measurements were carried out on these prototypes. There is good agreement between theoretical results and measurements.

Design, Analysis and Measurements of Reflected Phased Array Microstrip Antennas at Ka-band, using Hollow Phasing

A passive phasing technique for the designing microstrip reflectarray antennas is proposed. The antenna elements in the array are identical slotted patches. The slots are loaded with a SMD capacitor to set the required phase shift needed for array implementation. The design procedure and critical parameters are discussed and compared to alternative phase shifting techniques. Simulations show promising results. Mounting a SMD capacitor in such a configuration can be considered as the first step in using capacitive loading on a slotted patch for active microstrip reflectarrays. It is shown that by adjusting the capacitance values it is possible to scan the beam.

Reflectarray design using capacitive loading on a slotted patch

A new set of entire domain basis functions employable in the numerical solution via the Method of Moments (MoM) of the Electric Field Integral Equation (EFIE) on a metallic patch with a convex polygonal shape is presented in this paper. Such new basis functions are built by imposing both the boundary conditions for the normal component of the current density on the patch edges and other constraints coming from the physical distribution of the current on the metallization. Accuracy and fastness of common MoM procedure implemented by numerical codes based on subdomain basis functions are improved, when applied to patches with convex polygonal shape. Some numerical results are presented in order to show the capabilities of the new entire domain functions in the solution of radiation problems involving microstrip patch antennas.

MoM entire domain basis functions for convex polygonal patches

The problem of microstrip antennas covered by a dielectric substrate is formulated in terms of coupled integro-differential equations with the current distribution on the conducting patch as an unknown quantity. The Galerkin method is used to solve for the unknown patch current. Using the present formulation, the radiation pattern, the resonant frequency, and the bandwidth of a rectangular microstrip antenna are computed. Design data for a rectangular microstrip antenna are also presented.

/pdf/analysis-of-rectangular-microstrip-antennas-469mt8ft6p.pdf

M. D. Deshpande

Papers

Analysis of rectangular microstrip antennas