Wideband circularly polarised antenna based on tightly coupling effect

Abstract

A new design of a circularly polarised antenna based on the tightly coupled mechanism is presented. The proposed antenna consists of four tightly coupled dipoles, four impedance transforming networks and a wideband feeding network. Owing to the strong mutual coupling between coupled dipole elements, the proposed antenna realises a wide operating bandwidth. A prototype is manufactured and measured to validate the method. The measured results indicate that the proposed design provides a 10 dB return loss bandwidth of 101% (1.7-5.2 GHz) and a 3 dB axial ratio bandwidth of 77% (2.0-4.5 GHz). The design has a 3 dB gain bandwidth of 56% from 2.6 to 4.6 GHz with a peak gain of 10.4 dBic. Acceptable agreements can be obtained between the simulated and measured results.

Wideband circularly polarised antenna based on interelement mutual coupling effect

“…Nevertheless, they possess the overall size bigger than 2 λ 0 × 2 λ 0 . The bandwidth of [12, 14, 20] is reached about 87%, but the gain of edge band decreases rapidly. By contrast, the proposed wideband CP antenna in this paper provides an overlapped bandwidth of 94.2%, which is rarely in reported antennas.…”

“…To extend the operating bandwidth of small arrays, the introduced mutual coupling effect should be full consider with edge truncation effect and impedance matching. In [20], four curve dipoles were spaced end to end with interelement gaps. Through this structure, not only the circular E ‐field was formed, but also the tight coupling effect between elements was achieved and the edge effect was avoided.…”

A wide‐angle beam scanning circularly polarized, tightly coupled dipole array based on two‐layer parasitic ring structure elements

“…These works fully illustrate the attractive merits of the TCDA in wideband and wide-angle scanning array designs. However, few studies deal with a CP, TCDA (CP-TCDA), and these studies often use tightly coupled environments to achieved wideband CP, without considering scanning [17][18][19][20]. Dual linearly polarized TCDAs often adopt dual-offset topology, which can minimise undesired coupling between orthogonal elements [21], but this scheme also results in the phase centres of the two orthogonal elements not coinciding.…”

High efficiency broadband ellipse antenna array with tapered parallel-double transmission line feed network

“…Meanwhile, various wideband feeding networks have been investigated to broaden the IBW of the antenna array. As demonstrated in [11], two-class Wilkinson power divider was utilized to achieve a broad IBW for jS 11 j À10 dB of 101%, however, the gain of the antenna array at side frequency was lower than −5 dB, which revealed a low radiation efficiency. In [12,13], the results illustrated the array IBW was broader than single element, obviously, which means that Wilkinson power divider can ameliorate the bandwidth by sacrifice of the radiation efficiency.…”