Simple Reconfigurable Circularly Polarized Antenna at Three Bands

Abstract

In this paper, a simple design for a triple-band circularly polarized (CP) antenna with the capability of switching its polarization between dual-sense CPs is presented. The proposed antenna is comprised of a monopole loop antenna as a primary radiator. By placing a parasitic loop around the primary radiator, an additional CP band is achieved. Reconfigurability of the polarization between right-hand CP (RHCP) and left-hand CP (LHCP) at three different frequencies of 2.5, 3.3, and 3.8 GHz was realized by controlling the ON/OFF states of two PIN diodes. For validation, the fabricated antenna yielded an impedance bandwidth of 52.6% (2.34–4.01 GHz), while the axial ratio bandwidths for both the RHCP and LHCP states were 3.5% (2.47–2.56 GHz), 6.6% (3.20–3.42 GHz), and 2.4% (3.74–3.83 GHz). The measured broadside gains within the axial ratio bandwidth were 1.2, 2.7, and 1.4 dBi, respectively. Compared to other reconfigurable multi-band CP antennas, the proposed design is the first work to achieve a reconfigurable polarization at three distinct bands at a low fabrication cost by using only two diodes. The proposed antenna is suitable for WLAN and WiMAX applications.

Dual‐band polarisation reconfigurable grounded fractal slot antenna

“…A comparison between the proposed fractal inspired antenna and previously reported polarisation reconfigurable antenna is summarised in Table 3. The antenna presented in [1–13, 16–20], the switching element is placed within the radiating element or signal path and require complex biasing network for the switching. The proposed antenna is small in profile and large overall CP bandwidth.…”

“…The antenna presented in [20] is dual‐band and the performance is comparable to the proposed antenna but the upper CP bandwidth is less than the proposed antenna and the switching element is placed within the RF signal line. The Antenna presented in [18] is the tri‐band antenna having a wide impedance bandwidth, however, the size of the antenna is large and the overlapping CP bandwidth is smaller than the proposed antenna.…”

“…In [16], a trapezoidal monopole antenna having reconfigurable feed line and switchable grounded slots are proposed. A monopole antenna with switchable corner and loaded with a metasurface to enhance CP bandwidth is presented in [17] and a monopole antenna with a switchable square ring is presented in [18]. In [19], a discontinuous ring dipole antenna is presented for polarisation reconfigurability.…”

“…The antennas presented in [1–16] are limited by the narrow overlapping reflection and axial ratio (AR) bandwidths and provide single band CP reconfigurability. The switching elements are embedded within the radiating element in the antennas presented in [17–20], and hence the biasing network affects the antenna performance [21].…”

Frequency-Reconfigurable Multiband Antenna Based on Pin Switch for Wireless Applications

“…The reconfigurable antennas are based on the RF switches. In the literature [5][6][7][8][9][10][11][12][13][14] a few reconfigurable antenna designs are presented. The authors in [5][6][7][8], present some frequency reconfigurable antennas models using VO2 switches.…”