2026-01-12 Latest Published
By Naveen Jacob
Muralidhar Kulkarni
Krishnamoorthy Kandasamy
Progress In Electromagnetics Research B, Vol. 117, 1-15, 2026
Abstract
A bandwidth tunable, circularly polarized (CP) patch antenna, with complementary split ring resonator (CSRR), embedded on the ground plane is presented in this paper. The antenna is capable of switching between ultra-wide band (UWB) frequency response, spanning through 2.6 GHz to 12 GHz and a narrowband (NB) frequency response at 6 GHz. Excitation of CSRR results in negative permittivity medium, producing notch band response at its designed frequency. This notch band is shifted by varying the arm length of CSRR using PIN diodes. This will result in tuning the bandwidth (BW) of the NB response of antenna, spanning from 1 GHz to 4.4 GHz, by retaining the central frequency at 6 GHz. The fractional bandwidth can be varied in a range of 16% to 73.3%, exhibiting an increase by a factor of 4.58. The antenna also exhibits switchable circular polarization (LHCP/RHCP) at 6 GHz for both UWB as well as narrowband responses. A compact tunable multiband Artificial Magnetic Conductor (AMC) unit cell is also designed and is used to construct a Phase Gradient Metasurface (PGM). The radiating beam of the antenna is steered using the PGM as a reflector to obtain a beam steering angle of +36° for LHCP and -44° for RHCP radiations. The antenna is a promising solution for applications which demand bandwidth switching & beam steering, such as cognitive radio services.
