Spurious radiation suppression in microstrip monopulse antenna

Purpose This paper aims to introduce a new novel microstrip monopulse comparator system to reduce the spurious radiation from the comparator and the feed network for achieving better radiation performance. Design/methodology/approach Two substrate layers have been used for the microstrip monopulse comparator system. The feed network and the comparator circuits are on the first substrate layer and the microstrip array antenna is on the second layer. The elements of the array antenna are novel square four-sided narrow rectangular slot antennas built on a conducting plane. A commercially available computational software, CST microwave studio, has been used for the analysis of the system. Findings Two substrate layers have been used for the microstrip monopulse comparator system. The feed network and the comparator circuits are on the first substrate layer and the microstrip array antenna is on the second layer. The elements of the array antenna are novel square four-sided narrow rectangular slot antennas built on a conducting plane. A commercially available computational software, CST microwave studio, has been used for the analysis of the system. Practical implications The system is proposed for tracking moving targets. Originality/value Novel slot radiators are introduced as radiating elements in this paper. The antenna arrangement shields the comparator and the feed network circuits, reducing the spurious radiation significantly.

On the Design of Patch Antenna Array

In this paper, a coaxial fed patch antenna array for application in the 2.4GHz ISM band was implemented using the Ansoft HFSS software. Standard formulas were used to calculate different parameters of the antenna. These were just used as a basis of design as some parameters varied considerably during simulation. A good extent of the antenna design was hence done through trial and error. The proposed antenna was designed to work at 2.44GHz frequency band. A fractional bandwidth of 2.62%, which was not close to the desired 10% and a reflection coefficient of -18.2131dB were attained. This may have been brought about by poor impedance matching and a high level of spurious feed radiation and surface waves. A way of improving the bandwidth would have been to use proximity coupling feeding method which offers the highest bandwidth (as high as 13%) and is somewhat easy to model and has low spurious radiation. However, its fabrication would have been more difficult. A directivity of 8.53dB was achieved. This was a fairly high though directivity increase could have been studied through use of different substrate material and thickness.

Review Design of Slot Antenna Based on Ansoft HFSS Software

In this paper, a micro-strip fed slot antenna array for application in the 2.4GHz industrial, scientific and medical(ISM) band is implemented using the Ansoft HFSS software. Standard formulas are used to calculate different antenna parameters. The proposed antenna is designed to work at 2.4GHz frequency band. A half power beam width(HPBW) of 57°. A bandwidth of around 7.7% is attained. This may have been brought about by poor impedance matching and a high level of surface waves. A way of improving the bandwidth would have been to use proximity coupling feeding method which offers the highest bandwidth and is somewhat easy to model and has low spurious radiation. However, its fabrication would have been more difficult. A directivity of 2.01 dB is achieved. This is a fairly high though directivity increase could have been studied through use of different substrate material and thickness. Adjusting length and width of narrow slot loop antenna will influence on the resonance frequency and bandwidth. By using HFSS software, the characteristics of antenna are investigated and analyzed, including voltage standing wave ratio (VSWR), return loss and far field radiation patterns.

Higher-order Mode Rectangular Dielectric Resonator Antenna for 5G Applications

The excitation of the higher-order mode, in rectangular dielectric resonator designed was explored to enhance the antenna gain and detailed elaboration is presented in this paper. The antenna was fed by a 50Ω microstrip line through an aperture cut in the ground plane. Besides avoiding spurious radiation, this feeding technique gives flexibility in controlling the amount of coupling in order to reduce the Q-factor in the higher-order mode RDRA. A design was developed and subsequently simulated using Ansoft HFSS ver 16.0 by utilizing Duroid 5880 dielectric substrate with a thickness (ts) of 0.254 mm, a permittivity (εs) of 2.2 and a loss tangent (δ) of 0.001 at 15 GHz. The higher-order mode, RDRA achieved the measured gain at 9.76 dBi and the measured impedance bandwidth as much 2.5 GHz which is 4.7% more compared to the fundamental mode. The result should be considered suitable for 5G applications.

Wire-medium loaded planar structures: modal analysis, near fields, and radiation features

A novel transmission-line model is used for the analysis of planar structures, including wire-medium (WM) slabs with vertically aligned wires. The network formalism allows for an effective determination of the relevant spectral Green's functions, of the modal dispersion equation via transverse resonance, as well as of the far-field radiation pattern produced by simple sources via reciprocity, as opposed to the more cumbersome field-matching approach. Numerical results, validated also against state-of-the-art simulation software, confirm the accuracy and effectiveness of the proposed approach. In particular, modal and radiation features are presented for a class of leaky-wave antennas based on planar WM loaded configurations covered by partially reflecting screens, for which leaky unimodal regimes are achieved by minimizing spurious radiation from the quasi-transverse electromagnetic (TEM) mode.