Mohil Gala

Circular polarized tunable square slot cut elliptical patch microstrip antenna

In circularly polarized radiation, the rotational orientations of the transmitter and the receiver antennas are unimportant in relation to the received signal strength. In this paper, a center square slot cut elliptical patch microstrip antenna to realize a tunable circular polarization in 1000 MHz frequency band is proposed. It yields axial ratio bandwidth of nearly 1.2% over tunable range. A rectangular slot cut elliptical microstrip antenna is also proposed which provides return loss and axial ratio bandwidth of nearly 47 and 3 MHz. The proposed configurations yield broadside radiation pattern over entire bandwidth with antenna gain of more than 4 dBi 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 by using appropriate slot length.

Partial Corner Edge-Shorted Rectangular Microstrip Antenna Embedded with U-slot for Dual-Band Response

A design of dual-band rectangular microstrip antenna embedded with conventional U-slot and loaded with a partial shorting edge is presented. The paper presents a detailed analysis, which brings out the resonant mode explanation for dual frequency response. The U-slot first reduces and tunes the spacing between second-order shorted TM3/4,0 mode and fundamental shorted TM1/4,0 mode. This optimum spacing between two frequencies yields dual frequency response. Due to unidirectional current variations across shorted and slotted patch, antenna exhibits broadside radiation pattern at dual frequencies.

Broadband varying angle shorted sectoral microstrip antennas with rectangular slot

Broadband shorted Sectoral microstrip antennas with rectangular slot for Sectoral angle increasing from 50° to 120° are proposed. In shorted patch, rectangular slot reduces the resonance frequency of shorted higher order TM1/4, 1 mode and along with fundamental shorted TM1/4, 0 mode, yields broadband response. A maximum bandwidth of nearly 2000 MHz (>70%) is realized in shorted slot cut 120° Sectoral patch whereas shorted slot cut 50° Sectoral patch yields bandwidth of nearly 500 MHz (~50%). Due to shorted patch proposed antennas shows higher cross polar level radiation pattern thereby realizing elliptical polarization over a complete bandwidth. The antenna gives gain of around 2 to 3 dBi over the bandwidth. The proposed configurations can find applications in multi-path propagation environment wherein they will lead to lesser signal loss.

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.

Analysis of stepped half U-slot cut shorted SMSAs

Bandwidth of shorted compact Microstrip antenna has been increased by cutting modified half U-slot inside the patch. In this paper, a detailed study that highlights upon the broadband behavior in modified half U-slot cut shorted patch is presented. The modified half U-slot tunes the resonance frequency of higher order shorted TM1/4,1 mode with respect to fundamental TM1/4,0 mode to realize broadband response. The modified half U-slot also perturbs the surface current distribution at TM1/4,1 mode to give an broadside radiation pattern over the complete bandwidth. Thus the novelty of the proposed study lies in providing exact explanation for the broadband response in the slot cut shorted patch in terms of patch resonant modes, which is not available in reported literature.

Broadband slot cut S-shaped microstrip antenna

Bandwidth of compact S-shaped microstrip antenna has been increased by cutting S-shaped slot inside the patch. In this paper an analysis to study the broadband response in slot cut S-shape microstrip antenna is presented. The S-shaped slot in the patch tunes higher order TM20 mode frequency with respect to lower order TM10 mode, to realize bandwidth of more than 70 MHz (∼9%). The S-shaped slot modifies the surface current distribution at TM20 mode that gives broadside radiation pattern over complete bandwidth with peak broadside antenna gain of nearly 7.5 dBi. In the reported literature an explanation for broadband response in slot cut compact antennas in terms of their operating modes is not given. The novelty of proposed work lies providing detail explanation for working of slot cut patch antenna in terms of its resonant modes.

Angular cut circular microstrip antenna for multi-band dual polarized response

Analysis and design of multi-band dual polarized circular microstrip antenna with an angular cut and pair of rectangular slot in 1000 MHz frequency range is proposed. The angular cut degenerates TM11 and TM21 resonant modes of equivalent circular patch into two orthogonal modes to yield multi-band response. Further pair of rectangular slots optimizes the input impedance at degenerated resonant modes and also modifies the surface current distribution at them to realize bandwidth of 1 to 2% with broadside radiation pattern at each of the frequencies. The suspended configurations of proposed dual polarized antenna is also optimized, which gives more than 4 dBi of gain at each of the frequencies.

Dual polarized slot cut elliptical shaped microstrip antennas

This paper proposes a novel Multi-band dual polarized elliptical shaped microstrip antenna cut with square and rectangular slot. The square slot in elliptical patch degenerates patch TM11 and TM21 modes into two orthogonal modes to realize multi-band characteristics. The optimization of the input impedance at degenerated resonant modes is done by the introduction of the rectangular slot to realize optimum bandwidth of 1 to 2% in 1000 MHz frequency range. The proposed dual-polarized configuration yields broadside radiation pattern characteristics over all the resonant mode frequencies.

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.