Kshitij Lele

Dual polarized stub loaded microstrip Reflectarray with microstrip antenna feed

Microstrip Reflectarray with patches of variable stub lengths to realize progressive phase shift and dual polarization is proposed. Three different configurations namely, 1 × 3, 3 × 1 and five elementsarrays arranged in two co-ordinate axes are proposed. The beam width in allthe configurations in E and H-plane is around 21° with a gain of more than 11 dBi in five element crossed array.

Broadband CPW fed Stub loaded hexagonal slot backed hexagonal microstrip antenna

To cover Wi-MAX and WLAN frequency bands, variations of coplanar waveguide fed hexagonal shape microstrip antennas backed by hexagonal slot ground plane in 3500 MHz frequency range is proposed. In the first variation of hexagonal shape microstrip antenna, an impedance bandwidth of more than 100% is obtained whereas 300 rotated variation of hexagonal shaped patch yields increased bandwidth of nearly 108%. Further increase in bandwidth is realized by adding stubs on the hexagonal shaped ground plane. Stub loaded MSAs yields bandwidth of around 114% and 118% in the two configurations.

Broadband designs of shorted slot cut 60 sectoral microstrip antennas

Broadband variations of slot cut shorted 60° Sectoral microstrip antenna using multi-resonator technique, are proposed. The slot tunes the spacing between TM1/41 and TM1/4,0 modes of the shorted patch, to yield broader bandwidth. The gap-coupled variation of slot cut shorted 60° Sectoral patch with shorted 60° Sectoral patch yields bandwidth of more than 900 MHz (~75%) whereas gap-coupled variation of two slot cut and shorted 60° Sectoral patches yields bandwidth of more than 950 MHz (~78%). Due to the shorted patch, proposed configurations yields radiation pattern with higher cross polar levels with peak gain of more than 3.0 dBi.

Ultra-wideband modified rectangular microstrip antenna

A new ultra-wideband planar microstrip antenna obtained by combining rectangular and circular shaped planar monopole patches is proposed. The optimum feed-line position is obtained individually for rectangular and circular patches by studying their surface current distributions. The rectangular and circular geometries are then merged to obtain a modified configuration. A parametric study for varying distances between the centers of the circular and rectangular patches and also for the gap between the radiating patch and the ground plane is conducted. The proposed configuration yields an optimum bandwidth of more than 8 GHz and a gain of 1 to 3 dBi over the bandwidth.

Broadband E-shaped space-fed array with stacked E-shaped microstrip antenna array feed

Broadband Spaced fed array fed using stacked configuration of E-shaped microstrip antenna fed by E-shaped microstrip antenna is proposed. The modified feeding structure in space fed array is used as in higher order arrays, peripheral patches are not equally fed using single microstrip patch. The fed 3 × 3 stacked E-shaped patch array yields an optimum gain of nearly 9 dBi with VSWR bandwidth of around 2.1 GHz. The 3 × 3 stacked array is then used as a feed element for the space fed array variations. Various spaced fed array configurations of the stacked microstrip array, like 1 × 3, 3 × 1, plus shaped and 3 × 3 arrays are studied. An optimum result is obtained in 3 × 3 space-fed array configuration showing a gain of nearly 16 dBi with bandwidth of 2.1 GHz.

Circularly polarized sequentially rotated gap — coupled elliptical microstrip antennas array

In this paper a single fed elliptical microstrip antenna to realize circular polarization in 1000 MHz frequency band is proposed. It yields axial ratio bandwidth of 10 MHz (~1.2%). A sequentially rotated gap coupled configuration with a single parasitic patch along x axis is studied. Thereafter, gap coupled array along x and along y axis, i.e., a plus shaped array is studied to increase the ARBW. Also, 3×3 array is presented which provides return loss bandwidth and axial ratio bandwidth of 44MHz and 30MHz respectively with a gain of 1.5dBi for non-suspended configuration. For gain increment, suspended single elliptical microstrip antenna is proposed, which provides axial ratio bandwidth of 12 MHz and gain of 7dBi. The proposed gap coupled configurations yields broadside radiation pattern over entire bandwidth with antenna gain of more than 9dBi in their suspended variation. The proposed configuration can find applications in mobile communication environment in 1000 MHz frequency band and can also be tuned to a required frequency in the given range.

Space-fed microstrip array with proximity-fed microstrip antenna feed element

A space-fed array fed by a proximity fed microstrip antenna for a broader bandwidth is proposed. The 1 × 3, 3 × 1, plus-shaped and 3 × 3 configurations are studied. A parametric study for varying distances between the fed-patch and the array is done and the optimum results for each configuration have been presented. A bandwidth of 1.1 GHz and a gain of 14.6 dBi is obtained in 3 × 3 space fed configuration.

Broadband space-fed array with stacked microstrip array as feed element

Higher order space-fed arrays have limited gain due to unequal excitation of patches when fed by a single microstrip patch. Hence, a broadband space-fed array with a stacked microstrip array as the feed element is proposed. An array of rectangular microstrip antennas is placed on top of a co-axially fed broadband E-shaped patch antenna to realize a multi-layer stacked microstrip array. First, various configurations of the stacked microstrip array, like the 1 × 3, 3 × 1, plus shaped and 3 × 3 arrays, are studied. The 3 × 3 array yields an optimum gain of 8.25 dBi and a bandwidth of around 2.2 GHz. The 3 × 3 stacked array is then used as a feed element for a 3 × 3 space-fed array which yields a gain of 14.4 dBi and bandwidth of 2.15 GHz.

Design of rectangular Microstrip antenna backed by C - shaped defected ground plane

A novel design of rectangular Microstrip patch antenna backed by C shaped defected ground plane (DGP) is presented. First, effect of adding a slot in ground plane on fundamental mode is studied. A parametric analysis is performed by varying the slot width and changes in current distribution is observed. From this observation, approximate equations to calculate the resonant length of C shaped slot are proposed. Based on these equations, a dual band rectangular radiating patch antenna backed by C shaped defected ground plane is presented which gives dual bandwidth of 8MHz and 15MHz respectively.

Ultra-wideband star shaped planar monopole antenna

A novel design of ultra-wideband star shaped printed monopole antenna is proposed. A star shaped structure is realized by combining triangular shaped planar monopole patch with its inverted configuration. A detailed parametric study of the offset placement of two triangular shaped patches with respect to the patch centroids, variation in distance between the base of composite structure and the ground plane, is presented. To further improve impedance matching composite structure is chopped at the lower vertex point and a parametric study for the offset feed positions is carried out. The proposed antenna yields an optimum bandwidth of more than 8 GHz ranging from less than 2 GHz to more than 10 GHz with a broadside co-polar gain of around 1 to 2 dBi over a complete bandwidth.