High isolation compact four-port MIMO antenna systems with built-in filters as isolation structure

• In this work, we present a built-in filter method to enhance the isolation level between closely packed MIMO antennas. The built-in filter is composed of several slits etched on the ground of the antenna structure. The number and length of slits depend on both the resonance frequency and the structure of the MIMO antenna system. To illustrate its usefulness, two designs of compact planar four-port MIMO antenna systems with built-in filters are proposed. One MIMO system is composed of different types of antennas with similar radiation characteristics, such as polarization. The lateral size of the whole system is 0.64λ×0.48λ. To further reduce the size of the MIMO structure, polarization diversity is utilized in the second example. The dimension is only 0.4λ×0.4λ. In both cases, with the built-in filters, the isolation level can be improved by 10dB. In both MIMO systems, the measured port isolations between antennas are below -25dB, and the envelope correlations are smaller than 0.04, indicating good MIMO performance.

Ämnesord

TEKNIK OCH TEKNOLOGIER  -- Elektroteknik och elektronik (hsv//swe)

ENGINEERING AND TECHNOLOGY  -- Electrical Engineering, Electronic Engineering, Information Engineering (hsv//eng)

Nyckelord

Antenna structures

Envelope correlation

Filter method

High isolation

Isolation level

Isolation structures

Lateral sizes

MIMO antenna

MIMO antenna system

Polarization diversity

Port isolation

Radiation characteristics

Resonance frequencies

Whole systems

Antenna grounds

Decoding

MIMO systems

Polarization

Resonance

Antennas

Publikations- och innehållstyp

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