Sudesh Agrawal

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 CPW Fed Hexagonal Shape and Hexagonal Slot Cut Microstrip Antenna

The variations of Coplanar Wave guide fed hexagonal micro strip antennas with hexagonal slot ground plane are proposed in 3000 MHz frequency band. The first variation of hexagonal shaped micro strip antenna yields impedance bandwidth of more than 108% which covers Wi-MAX and WLAN bands. The hexagonal shaped patch is rotated in 300 backed by the same ground plane. This configuration yields higher bandwidth of nearly 115%. The proposed configurations show broadside radiation pattern with a gain of more than 6 dBi over most of the bandwidth.

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.

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.

Review on CPW – Fed Microstrip Antennas

A CPW-fed antenna with a semicircle placed on two rectangular patches for WLAN application and this antenna satisfies the frequency band (5.15 to 5.95 GHz) having return loss lower than -10 dB. A novel broadband design of a coplanar waveguide fed square slot antenna loaded with conducting strips is proposed and experimentally studied. A design of triangular wide slot antenna with same shaped patch which is fed by CPW and in this antenna patch is working as a radiating element and wide slot working as a ground. A wideband E-shaped microstrip patch antenna has been designed for high-speed wireless local area networks (IEEE 802.11a standard) and other wireless communication systems covering the 5.15– 5.825 GHz frequency band. A dual band coplanar waveguide (CPW)-fed planar monopole antenna suitable for WLAN application is been presented. A CPW-fed antenna with a triangle placed on a rectangular patch with two semi circles placed on either sides for WLAN application and this Antenna satisfies the licensed frequency band (5.15 to 5.95 GHz) having return loss lower than –10 dB.

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 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.

Design of gap-coupled variations of slotted and shorted 60° Sector microstrip antennas

Various configurations of slotted and shorted 60° Sector microstrip antennas for wider bandwidth are discussed. Slot tunes the spacing between shorted patch TM1/4,1 and TM1/4,0 resonant modes, that gives bandwidth of more than 800 MHz (>60%). The surface current distributions at modified shorted resonant modes were studied. Based on current variations against slot length, formulation in resonant length for shorted modes is proposed. Using proposed formulations frequencies were calculated. They show close agreement with simulated frequencies. The proposed formulations were further used to design slot cut gap-coupled shorted variations at different frequency on thicker air substrate. In all the configurations design procedure achieves wide band response.

U-slot cut shorted square microstrip antenna

By cutting U-slot, bandwidth of shorted square microstrip antenna has been increased. Here, detailed analysis which explain the effects of U-slot to achieve wide band response in shorted square patch is presented. U-slot yields tuning of TM3/4,0 mode frequency with respect to shorted patch TM1/4,0 mode, thereby it gives 27% of bandwidth in 2.4 GHz range. Slot also modifies current distribution at second order mode to give broadside radiation pattern over the bandwidth. An insight into the functioning of widely reported U-slot cut shorted square patch antennas in terms of patch resonant modes is provided here. This study will serve as a tutorial to re-design similar antennas at any given frequency.