Manotosh Biswas

Microstrip Patch Antenna With Defected Ground Structure for Cross Polarization Suppression

A defected ground structure (DGS) is proposed to reduce the cross-polarized (XP) radiation of a microstrip patch antenna. The proposed DGS pattern is simple and easy to etch on a commercial microstrip substrate. This will only reduce the XP radiation field without affecting the dominant mode input impedance and co-polarized radiation patterns of a conventional antenna. The new concept has been examined and verified experimentally for a particular DGS pattern employing a circular patch as the radiator. Both simulation and experimental results are presented.

Concentric Ring-Shaped Defected Ground Structures for Microstrip Applications

A new defected ground structure (DGS) consisting of concentric circular rings in different configurations is experimentally studied to examine the stopband characteristics. Unlike previous DGS designs, a metallic shielding is introduced at the back of the DGS to suppress any leakage or radiation, and this would be advantageous for microwave circuit applications. A wide stopband is demonstrated with a set of prototypes designed for X-band. Its application to suppressing mutual coupling in microstrip patch arrays is demonstrated

Effect of a Cylindrical Cavity on the Resonance of a Circular Microstrip Patch With Variable Air-Gap

The effect of a cylindrical cavity enclosure in shifting the resonant frequency of a suspended substrate circular microstrip patch with variable air-gap is investigated and an analytical formulation is proposed to accurately estimate the same. A new factor indicating the proximity effect of the cavity wall is also suggested and studied. The proposed formula is compared with some measurements and simulated data generated using Ansofts HFSS v9.2 revealing much closer agreement compared to a previously reported formulation

Harrington's Formula Extended to Determine Accurate Feed Reactance of Probe-Fed Microstrip Patches

A simple formulation is presented as an extension of Harringtons formula to accurately estimate the feed reactance of probe-fed microstrip patches. This, unlike previous formulas, can efficiently address all sorts of variations of microstrip and probe parameters resulting in a more versatile form. Computed results are verified with some representative measured data on rectangular and circular microstrips, thus, providing confidence in the new formula and its accuracy

New CAD model for cavity-backed circular microstrip antenna

In this paper, a new CAD model is proposed to estimate the accurate resonant frequency and input impedance of a cavity backed circular microstrip patch antenna. The computed results are examined for different patch and cavity dimensions and are also verified with experimental results.

Experimental investigation of an equilateral triangular microstrip antenna with a dielectric radome

The effects of a radome on the resonance and input impedance characteristics of a triangular microstrip antenna are experimentally investigated. To the best of our knowledge, this is the first time that the experimental results on superstrate loaded triangular microstrip patch are reported.

Microstrip radiating structures: Theoretical and experimental investigations executed in recent years at the University of Calcutta

In this paper, we have presented a comprehensive review of research on microstrip antennas conducted at the Institute of radio Physics and Electronics, University of Calcutta with an emphasis to those done in recent years.

CAD of mechanically tunable rectangular microstrip patch with variable aspect ratio

An improved CAD formulation is proposed to determine accurate input impedance of rectangular microstrip patches with variable aspect ratio. This paper demonstrate the effect of aspect ratio of rectangular microstrip patch on its input impedance. The computed results have been verified with our own experiments and simulated data showing very close agreement amongst them.