Abstract
A tapered symmetrical coplanar waveguide (S-CPW) fed monopole antenna is initially studied. To achieve multiband characteristics, the radiating element of this monopole antenna is loaded with multiple narrow slots and multiple slotted stubs (MSS). The designed slot-loading monopole is further transformed into a two-antenna MIMO type with a gap distance of only 0.12λ (at 5 GHz), and thus it has a small overall size of 32 × 20 × 0.8 mm3. By deploying five concentric ring elements between the two adjacent antenna elements, the desirable isolation of better than 20 dB is yielded. As the low band and high band operation of the proposed two-antenna MIMO is 81.08% (3.3–7.8 GHz) and 40% (8.0–12.0 GHz), respectively, it can therefore satisfy the Sub-6 GHz 5G New Radio (NR) n77/78/79, IEEE 802.11ac/ax, X-band/C-band wireless and satellite applications. Furthermore, it has shown a desirable gain of above 3 dBi and a radiation efficiency greater than 69% throughout the two bands of interest.
Highlights
The main challenging part of designing a compact size MIMO antenna is to obtain a very high isolation of >20 dB between the two adjacent antenna elements without affecting the scattering, radiation, and diversity performances
To prove the potency of the proposed two-antenna MIMO, the diversity performances matrix, such as Envelope Correlation Coefficient (ECC), Diversity Gain (DG), Mean Effective Gain (MEG), Capacity Loss (CCL), channel capacity, and Total Active Reflection Coefficient (TARC), are very essential, and they are further verified through simulation as well as measurement
A two-antenna MIMO functioning in the Sub-6 GHz 5G New Radio (NR), IEEE 802.11ac/ax, Cband, and X-band has been successfully studied
Summary
The main challenging part of designing a compact size MIMO antenna is to obtain a very high isolation of >20 dB between the two adjacent antenna elements without affecting the scattering, radiation, and diversity performances. The easiest way to reduce the mutual coupling of any two adjacent antenna elements is to apply the spatial diversity method The advantage of this method is that the MIMO antenna does not require any decoupling structure, such as the one reported in [9] that has a gap distance of 36 mm (>1/4 wavelength) between the two adjacent antennas, and good isolation of >30 dB is achieved. To achieve a small volume size of 47.5 × 40 × 1.6 mm3, [21] has proposed a single band, two-antenna MIMO monopole that has applied a metamaterial split ring resonator unit to improve the isolation. In this paper, a compact volume size (32 × 20 × 0.8 mm 512 mm3) two-antenna monopole MIMO with a dual wideband operation (3.3–7.8 GHz and 8.0–12.0 GHz), as well as high isolation (>20 dB) for the wireless and satellite applications is proposed.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
