In this communication, an all-metal standing wave antenna array is proposed based on the microstrip transmission line. By alternatively blocking the microstrip line every half wavelength, the symmetrical equivalent magnetic currents are broken for effectively radiating. By properly tuning the blocking positions along the microstrip line, a broadside pattern is achieved with high gain. The proposed antenna is scalable along one direction to a certain level to acquire the directivity as high as about 15 dBi. More importantly, the proposed antenna array has the potential to be built only by metal without any dielectrics. The all-metal structure has the merits of being low-cost, light weight, easily fabricated, and having no dielectric losses. Based on this idea, a five-segment linear array with a center feed is designed and tested. The measured bandwidth is from 7.83 to 8.81 GHz (980 MHz, 11.78%), and the measured gain is ranging from 9.1 to 12.47 dBi.

All-Metal Antenna Array Based on Microstrip Line Structure

This paper concerned on enhancement of gain for microstrip patch planar array antenna. The structure in this project is 2 by 2 microstrip patch planar array antenna using air substrate with e r = 1at frequency 5.8 GHz. Frequency for 5.8GHz can be applied to unlicensed WiMAX. In this project, the simulation is performed by using the simulation software Computer Simulation Technology (CST) Microwave Studiowhich is a commercially available electromagnetic simulator based on finite difference time domain technique. The novelty of the design is the application of air to replace regular Flame Retardant 4 (FR-4) materials as the substrate.The substrate used for the design is C-foam (thickness = 3mm) which represent as air gap. Copper foil with thickness 0.12mm is used as the patch. The performance of the designed antenna was analyzed in term of bandwidth, gain, return loss, VSWR, and radiation pattern.

Gain enhancement of air substrates at 5.8GHz for microstrip antenna array

The popularity of microstrip antennas is increasing day by day because of ease of analysis and fabrication. This paper concerned on enhancement of gain for microstrip patch planar array antenna by using air substrate. The structure in this project is 2 by 2 microstrip patch planar array antenna with substrate e r = 1at frequency 5.8 GHz. Frequency for 5.8GHz can be applied to unlicensed WiMAX. In this project, the simulation is performed by using the simulation software Computer Simulation Technology (CST) Microwave Studio which is a commercially available electromagnetic simulator based on finite difference time domain technique. In this design the application of air to replace regular Flame Retardant 4 (FR-4) materials as the substrate. The substrate used for the design is air which is the thickness equal to 3mm . The thickness for the patch in this design is 0.12mm while the thickness for the ground is equal to 0.035mm. The performance of the designed antenna was analyzed in term of bandwidth, gain, return loss, VSWR, and radiation pattern.

Improving gain performance by using air substrate at 5.8GHz

A Rectangular
Microstrip Patch Antenna model is proposed using air as a substrate to study
the characteristics of designed antenna. The dimensions of designed antenna are 17 mm × 16.66 mm with
substrate at frequency 3.525 GHz. In this paper,
the simulation is performed by using software Computer Simulation Technology
(CST) Microwave studio based on finite difference time domain technique. The
characterization of the designed antenna was analyzed in terms of return loss, bandwidth, directivity, gain, radiation
pattern, VSWR.

/pdf/rectangular-microstrip-patch-antenna-using-air-as-substrate-2xi6i791nu.pdf

Rectangular Microstrip Patch Antenna Using Air as Substrate for S-Band Communication

In this letter, an air substrate two-dimensional chessboard cavity antenna with scalable radiating aperture is proposed for high-gain applications. The proposed cavity antenna is composed of $M$  ×  $N$ open cavity units, arranged properly in a planar chessboard topology structure. Benefiting from the structure scalability, a much larger radiating aperture with high gain can be achieved using an appropriate excitation approach. Another merit from the chessboard structure is the air-filled medium without suffering from the high dielectric loss for high-frequency usage. Each unit of the cavity antenna can be supported stably by the shorting sidewalls of itself and adjacent units, not by substrate as usual. To validate the design strategy, a 4 × 5 air-filled chessboard cavity antenna is built and tested. The peak gain of 17.28 dBi is measured in the operation band of 8.35–8.74 GHz (4.56%), exhibiting the potentials in the directional wireless communication applications.

Air Substrate 2-D Planar Cavity Antenna With Chessboard Structure

A rectangular microstrip patch on air substrate is theoretically and experimentally demonstrated and compared with conventional microstrip patch. Compared to conventional one, these show improved radiation performance. Around 2–3 dB improvement of peak gain observed.

http://ieeexplore.ieee.org/iel5/5436188/5441033/05441099.pdf

C. Chandan

Papers

Radiation characteristics of rectangular patch antenna using air substrates