In this study, a two‐element multiple‐input–multiple‐output (MIMO) antenna with heptaband characteristics is proposed. The total size of the proposed antenna is 82 × 40 × 0.8 mm3. The geometry of the radiating element is derived from a hybrid Quadric–Koch island fractal for size miniaturisation. The antenna operates at the bands of 0.95–1.02 GHz (GSM 900), 1.73–1.79 GHz (GSM 1800), 2.68–2.85 GHz (LTE‐A), 3.66–3.7 GHz [ultra‐wideband (UWB)], 4.20–4.40 GHz (UWB), 5.50–5.65 GHz [worldwide interoperability for microwave access/high‐performance radio local area network] and 5.93–6.13 GHz (UWB). The spacing between the two radiating elements is maintained at 5 mm. The proposed heptaband swastik arm MIMO antenna exhibits an S11 ≤ −6 dB and S21 ≤ −17 dB over the entire bands of operation. It provides high isolation without requiring any additional structures. The antenna also offers stable radiation characteristics with circular polarisation at the operating bands of 3.66–3.7 GHz and 5.93–6.13 GHz and linear polarisation at 0.95–1.02 GHz, 1.73–1.79 GHz, 2.68–2.85 GHz, 4.20–4.40 GHz and 5.50–5.65 GHz bands. The diversity performance of the antenna is studied in terms of the envelope correlation coefficient which is <0.05, and capacity loss which is <0.5 bits/s/Hz at all the operating frequencies, making it suitable for use in fifth generation communication systems incorporating the existing bands.

In this article, a compact 2 element UWB MIMO antenna is proposed. It has a compact size of 40 mm × 20 mm (800 mm 2 ). The antenna utilizes hybrid Sierpinski Koch fractal shape as the radiating element. The antenna elements are

A miniature two‐element MIMO multiband planar patch antenna with potential applications in the ISM bands is presented. The elements of the antenna have been designed using a novel hybrid fractal geometry based on an altered Dragon Curve and the Inverted Koch. Reduced antenna dimensions are obtained with acceptable performance even at lower frequency ranges. The antenna elements are placed adjacent to each other with a very small spacing of 0.004 λ0 (λ being the free space wavelength of 433 MHz), confining the antenna dimensions to 51 × 50 mm2. The antenna resonates at the 433 MHz (ISM), 2.4 GHz (ISM), 3.9 GHZ (Fixed Satellite), 4.7 GHz (UWB) and 5.8 GHz (ISM) frequency bands. The antenna exhibits |S11| ≤ −10 dB, |S21| ≤ −16 dB, an ECC ≤ 0.01 for all operating frequencies, with circular polarisation at the 2.4 GHz and 5.8 GHz bands and linear polarisation at the others. The simulated structure was fabricated and tested, with the simulated and measured results displaying acceptable agreement.