Design of Triangle-Shaped Ground Multiband MIMO Antenna for X-BandM-B, K-BandM-B (Partial) and Satellite Uplink/Downlink Applications

A square-shaped Multi-Band (M-B) antenna with Multiple I/P Multiple O/P (MIMO) functionality is introduced for satellite application bands and microwave bands. A square radiating patch in a square shape with a Ctype slot, featuring dimensions of 30 × 16 mm2 designed on FR4 substrate connected through a 50Ω feeding line. The design aims to enhance isolation and achieve resonance within specified frequency bands. The integration of a triangularshaped stub onto the rectangular ground contributes to a wide bandwidth, catering to applications such as satellite uplink/downlink frequency <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">M-B</inf> (7.25 - 7.75 GHz & 7.90 - 8.40 GHz), X-Band <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">M-B</inf> (8.0 – 12.0 GHz), and partial K-Band <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">M-B</inf> (18.5 – 22.5 GHz). Applications of such achieved bands for monitoring weather, defence tracking purposes, radar systems etc. The antenna exhibits good isolation and maintains a low correlation with connected grounds, which is crucial for optimal performance. Orthogonal positioning of the radiating patch reduces coupling and improves diversity performance. Moreover, the antenna's MIMO diverse properties, including impedance bandwidth, Envelope Correlation Coefficient <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">M-B</inf> (ECC <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">M-B</inf> ), Total Active Reflection Coefficient <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">M-B</inf> (TARC <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">M-B</inf> ), Diversity Gain <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">M-B</inf> (DG <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">M-B</inf> ), Channel Capacity Loss <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">M-B</inf> (CCL <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">M</inf> B), Radiation Characteristics, and peak gain, are thoroughly analyzed. The proposed design demonstrates a ECC <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">M-B</inf> < 0.3 & a peak gain <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">M-B</inf> of 2-4 dBi across a broad bandwidth of 2-24 GHz. The developed structure exhibits improved isolation, operates efficiently over a wide frequency range, and maintains a compact form factor without compromising diversity performance.