Priyal Zaveri

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.

On the design of circularly polarized U-slot cut square microstrip antenna

Circularly polarized microstrip antenna realized by cutting unequal arm length U-slot is discussed. In 2.3 GHz frequency band, it gives VSWR and axial ratio bandwidth of 9 and 4%, respectively. In the reported work, a detailed explanation about the working of circular polarized antenna in terms patch resonant modes and the equations/design procedure to realize similar antennas at different frequency is not explained. In this paper, an in-depth analysis which explains the effects of unequal lengths U-slot to give circularly polarized response is presented. First the equal lengths of U-slot reduce the resonance frequencies of patch TM01 and TM20 resonant modes. An unequal length in U-slot arms (asymmetrical U-slot) leads to excitation of new resonant mode whose current distribution is similar to TM01 mode of U-slot cut patch. This gives circularly polarized response. Further equations for various patch parameters for U-slot cut antenna are proposed. Using them U-slot cut patch was designed at 1500 MHz. At this frequency antenna yields VSWR and axial ratio bandwidths of 138 (9.6%) and 60 (4.3%) MHz, respectively. Thus proposed equations are useful for designing U-slot cut antenna at any given frequency on thicker air substrate.

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.

Analysis of circularly polarized E-shaped microstrip antenna

Circular polarized response is realized when two orthogonal closely spaced resonant modes are excited in the patch. An E-shaped patch design using unequal lengths rectangular slots to give circular polarized response was reported. In the reported paper, proper analysis on resonant mode excited in the patch that gives circularly polarization is not explained. An extensive analysis explaining the effects of unequal length slots that gives circularly polarized response is presented in the present paper. The rectangular slots realizes tuning of higher order TM02 mode with respect to fundamental TM10 mode. Further, unequal lengths of two slots and feed point location optimizes the surface current contributions in orthogonal directions inside the patch which yields circularly polarized response. Thus, proposed study gives an insight into the functioning of circular polarized antenna that will help in designing similar configuration at other required frequencies.

Ultra-wideband plus shaped microstrip antenna

With the advancement in personal mobile communication systems, need of antennas that gives ultra-wideband response has increased. In this paper a novel ultra-wide band plus shaped planar Microstrip antenna is proposed. The plus shaped structure is realized by combining two rectangular shaped planar monopole printed patches. A details parametric study to realize the ultra-wideband operation in 3 to 10 GHz frequency band is presented. The proposed antenna yields operating bandwidth from less than 2 GHz to more than 10 GHz with broadside co-polar gain of around 1 to 3 dBi over complete bandwidth. Due to the realized bandwidth and gain, proposed configuration can find applications in personal mobile communication, blue tooth and Wi-Fi applications in 3 to 10 GHz frequency range.

Sequentially rotated gap-coupled circular slot cut circular microstrip antennas

Circular polarized microstrip antennas are required in applications wherein an uncertainty in the direction of received signal polarization exist. In this paper an offset slot cut circular microstrip antenna to realize circular polarization in 1000 MHz frequency band is proposed. It yields axial ratio bandwidth of 10 MHz (~1.2%). To increase the axial ratio bandwidth its gap-coupled array configuration with parasitic offset circular slot cut circular patches is proposed. A maximum return loss and axial ratio bandwidth of nearly 44 (~4.5%) and 18 MHz (~2.0%), respectively is obtained in gap-coupled configuration of circular patches along y-axis. The proposed configurations yields broadside radiation pattern over entire bandwidth with antenna gain of more than 4 dBi in their suspended variation. The proposed gap-coupled array configuration can find applications in mobile communication environment in 1000 MHz frequency band.

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.

Dual-band dual polarized D-shaped microstrip antenna

Design and analysis of novel dual-band dual polarized D-shaped microstrip antenna is proposed. The D-shaped microstrip antenna excites TM10 and TM01 modes which are orthogonal to each other, thereby realizing dual polarized antenna characteristics. Further, another novel configuration, a vertical slot cut D-shaped patch is proposed. The slot cut D-shaped patch demonstrates triple band dual polarized antenna response, with bandwidth of 1 to 2% at each of the frequencies in 1000 MHz frequency range. The proposed dual-polarized configuration yields broadside radiation pattern across all the resonant modes.

Sequentially rotated gap-coupled angular slot cut circular Microstrip Antenna arrays

Circularly polarized sequentially rotated gap-coupled array configuration of angular Sectoral slot cut circular Microstrip Antenna in 1000 MHz frequency band is proposed. The angular Sectoral slot degenerates TM11 mode into two orthogonal modes to give axial ratio and VSWR bandwidth of 10 and 43 MHz, respectively, in a single patch. To increase gain and axial ratio bandwidth, sequentially rotated gap coupled array configurations of angular Sectoral slot cut circular microstrip antenna are proposed. On thinner glass epoxy substrate, maximum VSWR and axial ratio bandwidth of 52 and 32 MHz, respectively is obtained in 3 × 3 array configuration. While optimizing on lossy thinner substrate, due to 3 × 3 array configuration, antenna yields broadside co-polar gain of nearly 2 dBi. In 1000MHz frequency band, the proposed configuration can find applications in wireless communication systems where transmitter and receiver antenna orientations are not important.

Ultra-wideband compact ring Sector printed monopole antenna

A novel compact ultra-wideband circular ring sector printed monopole antenna with decreasing Sectoral angle and modified feeding structure is proposed. A detailed parametric study for Sectoral angle decreasing from equivalent circular monopole patch to 330° ring Sector up till 60° ring Sectoral patch is presented. With decreasing angle ultra-wide band response with increasing lower frequency of the realized bandwidth is obtained in all the Sectoral patches. For Sectoral angle of 90°, an optimum response with offset feeding structure is realized. All the proposed Sectoral configurations yield bandwidth from less than 3 GHz to more than 10 GHz, thereby covering entire ultra-wide band frequency range. The proposed configurations yields gain of more than 1 to 2 dBi over the entire ultra-wide band frequency range.