Design, optimization and experimental verification of UWB-MIMO antenna with WLAN and complete X-band notched characteristics, checked with characteristic mode analysis (CMA)

In this proposed work, a compact Multiple Input Multiple Output (MIMO) antenna is designed for Ultra-Wide Band applications with dual-notch band characteristics is presented. Widely available low cost FR4 substrate is used for fabrication and the overall dimensions of the antenna are 24 × 36 mm2 (0.248 λ0 × 0.372 λ0, λ0 measured at lower band) having a height of 1.6 mm, dielectric constant 4.4. The proposed dual-band MIMO antenna operates from 3.1 to 13.4 GHz and an isolation higher than 15 dB is achieved in the entire working band with notched bands at Wireless Local Area Network (WLAN) and X-bands. The obtained radiation efficiency values are above 90% with a maximum value of 97% at 4 and 7 GHz bands and higher peak gain values are achieved with a maximum value of 7.4 dBi at the operating bands. The MIMO checking parameters (Envelope Correlation Coefficient, Diversity Gain, Total Active Reflection Coefficient, Channel Capacity Losses and Mean Effective Gain) are also presented for the proposed design giving good diversity performance chatacteristics in the entire operating band and also at the notch bands. The 3D polar plots are presented for the proposed design is providing high gain values and also presented negative gain is occurred at notched bands. The proposed single notched design S-parameters results are checked with Characteristic Mode Analysis. The fabricated model is tested and verified experimentally and these values are well matched with simulated once.