ESPAR antenna based diversity scheme for multiple antenna OFDM system

Micro & Optical Tech Letters

2018

In this study, a high‐gain electrically steerable parasitic array radiator (ESPAR) antenna using a collinear dipole array as a feed element is proposed, and its radiation characteristic is discussed. The feed element of the proposed antenna has a higher gain than existing ESPAR antennas, and it makes impedance matching easier via a length of coaxial cable between the arrayed feed elements and the thickness of the dielectric, using a collinear dipole array of circular dipole antennas. The proposed antenna is structured with feed elements of two‐layer collinear circular dipole arrays surrounded by four parasitic elements with an array radius of λ/16. The variable directional radiation pattern and high‐gain characteristic can be achieved through changes in reactance between the parasitic elements. The gain of the proposed antenna is 7.2 dBi approximately at the center frequency, and the return loss is less than −15 dB at the used frequencies of 2.4–2.5 GHz.

Section: Fabrication and Measured Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Characteristics of high‐gain ESPAR antenna using collinear dipole array

Micro & Optical Tech Letters

2018

“…As it uses a single active element without requiring elements such as a power divider, phase shifter, and so forth, it can considerably decrease the volume of the overall system compared to the phased array antenna. The system cost is much cheaper, too .…”

Section: Introductionmentioning

confidence: 99%

The characteristics of broadband ESPAR antenna with coupled multiconductor strips

Son

Microw. Opt. Technol. Lett.

2015

frequency 3.35 GHz) and 16.52% (at center frequency 3.57 GHz) in the broadside direction (h 5 08, U 5 08) shown in Figure 7. It is observed that in the Figure 8 the RHCP is stronger than the left hand circular polarization (LHCP) in broadside direction so, the proposed antenna is called RHCP. The simulated and measured RHCP and LHCP radiation patterns in xz-and yz-plane at 3.35, 3.55, and 3.75 GHz are shown in Figure 8. It has been found that in broadside direction the RHCP leads the LHCP by 226.63 dB, 219.28 dB, and 226.05 dB at 3.35 GHz, 3.55 GHz, and 3.75 GHz, respectively. The electric field distribution observed inside the DRA at different phase, that is, 08, 908, 1808, and 2708 confirms the proposed design is CP and it also confirms that the mode of DRA is TE 12d mode shown in Figure 9. The average gain and radiation efficiency is 4.69 dB and 74.84% in the working band shown in Figure 10. Table 1 show the comparison of earlier published work. It has been observed that proposed work shows improvement in AR bandwidth within working band over earlier reported design. CONCLUSIONIn this article, a new modified microstrip-line-fed rectangular dielectric resonator antenna coupled with slotted ground plane for circular polarization has been proposed. The measured impedance bandwidth is 17.87% (at center frequency 3.58 GHz) and measured AR bandwidth of proposed antenna is 16.52% (at center frequency 3.57 GHz) in the broadside direction (h 5 08, U 5 08), respectively. The proposed dielectric resonator antenna offer simple construction with sufficient bandwidth and excellent far-field properties. TE 12d mode has been excited in this proposed antenna. It has been observed that the proposed antenna shows RHCP in broadside direction (h 5 08, U 5 08). This antenna can be suitable for Wi-MAX (3.3-3.6 GHz) applications.

Design of the ESPAR antenna with improved DC bias

Micro & Optical Tech Letters

2015

In this article, an electrically steerable passive array radiator antenna was designed, consisting of a cylindrical dipole active element and four flat dipole parasitic elements. Using a varactor diode, which is a variable capacitor, reactance was applied to the parasitic elements and beam steering to a preferred direction can be achieved through the reactance change. A common ground was used for negative voltage applied lines, which were DC bias lines to control varactor diode voltage, with the active element ground. Using this structure, the number of DC bias lines could be reduced, resulting in the advantage of constructing a simple control circuit. In addition, using a quarter-wave meander strip line in the negative voltage applied lines, a voltage standing wave ratio characteristic was improved and an antenna gain was increased.