This Letter explains the design and development of a wideband circularly polarised (CP) antenna based on composite metamaterial (MTM) structures which are applicable for use in small satellite applications. The presented antenna is based on a modified co-planar waveguide feeding technique. The proposed antenna unit cell offers compact size due to its MTM property with dimensions of 0.088λ 0 × 0.19λ 0 at 2.4 GHz. The CP radiation is obtained by placing two composite right/left-handed transmission line unit cells orthogonally and exciting two orthogonally-polarised modes simultaneously. A new 4 × 4 unit cell artificial magnetic conductor metasurface is designed with a compact size at the same operating frequency of MTM-based CP antenna as a ground plane for the proposed antenna, which is found to be increased bandwidth, improved gain, and wider axial ratio bandwidth without altering the antenna compactness. The final antenna obtains an overall dimension of 0.37λ 0 × 0.37λ 0 × 0.18λ 0 at 2.5 GHz. The measured result shows a wider impedance bandwidth of 860 MHz (33.07%), improved axial ratio bandwidth of 410 MHz (15.92%), and a good gain of 5.76 dBic is obtained which are adequate for the use in modern small satellite applications.

A single probe-fed novel V slit, stub and slot embedded circular microstrip antenna with resonances in the three bands of UMTS, worldwide interoperability for microwave access (WiMAX) and WLAN is presented. The polarisation is circular in the UMTS band and linear in the other two bands. Asymmetrical V slits in the patch boundary along with an embedded circular slot in the patch centre are employed to introduce the perturbation necessary for circular polarisation. Impedance bandwidths (BWs) of 4.2, 2 and 6.2%, respectively, in the three bands centred at 2, 3.5 and 5.6 GHz are obtained. The axial ratio BW is 2.3% in the UMTS band. Moderate gains of 4.4, 3.5 and 2.8 dBi are obtained in the three bands. There is a patch size reduction of about 48% when compared with the conventional circular patch antenna at a fixed operating frequency. The radiation pattern is directional in the WiMAX band and nearly omnidirectional in the WLAN band.

This work explains the design and development of a low profile and compact single probe-fed metamaterial (MTM)-based circularly polarised (CP) antenna using the modified rectangular patch with two pairs of spiral strips and vias for 5.2/5.8 GHz WLAN applications. The intended CP antenna mainly consists of two pairs of radiators and each radiator is realised by using epsilon negative (ENG) transmission line (TL) to generate zeroth-order resonance. CP characteristics are achieved by placing two radiators for x-polarised wave are orthogonally aligned to the other two radiators for y-polarised wave. The antenna radiating element offers a compact size of 0.24λ 0 × 0.22λ 0 with a low profile of 0.04λ 0 at 5.5 GHz. To confirm the characteristics of the intended MTM CP antenna design, the designed antenna is fabricated and measured. Measurement results show that the antenna obtains −10 dB impedance bandwidth of 610 MHz (10.86%) which is 2.3 times larger than the standard microstrip patch antenna and axial ratio bandwidth of 140 MHz (2.54%) is obtained.

In this article, a miniaturized metamaterial (MTM) inspired antenna with triple band characteristics is presented for LTE/WLAN/WiMAX applications. The antenna mainly consists of a square shaped split ring resonator (SRR) with rectangular stub connected in the outward direction. Due to inward flipping of the same rectangular stub leads to 20% antenna miniaturization without degrading the resonance behavior. The SRR produces first and second band, while the third band is enhanced due to flipping of inward stub and addition of rectangular type slot in the partial ground plane. The antenna exhibits tri-band characteristics with each bands centered at 2.23, 3.65, and 5.13 GHz, having −10 dB impedance bandwidth of 9.42%, 12.88% and 15.34% for the first, second, and third band, respectively. The antenna has a footprint size as low as 0.16 λ 0 × 0.18 λ 0 × 0.012 λ 0 corresponding to 2.23 GHz with a measured gain of 2.22, 2.31, and 1.98 dBi., and measured radiation efficiency of 70%, 72.75% and 82.57% in the three bands, respectively. The prototype of the antenna is fabricated and simulated results are verified through measurements.

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This Letter demonstrates the design of a two-element polarisation diversity antenna, applicable for modern small satellite application systems. The intended antenna mainly consists of two monopole radiators loaded with metasurface reflector as a ground plane. The dimensions of the radiator antenna are 40 × 22 × 1.6 mm 3. The antenna measured results offers a wider S 11 bandwidth of (2.23-2.91 GHz) and wider axial ratio bandwidth (ARBW) of (2.16-2.92 GHz) with a common S 11 and ARBW of 26.45% is obtained. A maximum gain of 7.02 dBic and isolation better than 14.5 dB is observed along with the operating frequency range. The antenna provides an ARBW (< 3 dB) and gain (> 2.38 dBic) for theta = ± 45°, for all phi values along with the complete operating frequency range. Also, the antenna port-1 provides left-handed circular polarisation and port-2 provides right-handed circular polarisation radiation with directional radiation characteristics.

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