A Compact Monopole Array with Increased Port Isolation

Abstract

Strong mutual coupling between closely spaced elements in compact antenna arrays may cause significant system performance degradation. Decoupling networks can be used to compensate for the mutual coupling effect. In this paper, a new compact network structure is proposed to enhance the port isolation between three closely spaced antennas. This 6-port network consists of only a microstrip ring. Transmission lines are used to connect the output ports of the network to the terminals of the three-element array. Open stubs match the input ports of the network to the system impedance. A three-monopole array with the proposed decoupling and matching network was fabricated. The experimental results show that port isolation is achieved for this compact three-monopole array.

Mutual Coupling Reduction Between Printed Dual-Frequency Antenna Arrays

“…Various techniques to reduce the mutual coupling of antenna arrays have been reported. The decoupling networks using reactive components [1], microstrip sections [2] or hybrid couplers [3,4] can be added to the feeding ports of the array to reduce mutual coupling. In signal processing, the coupling matrices using receiving mutual impedance [5][6][7] can be applied to compensate for the mutual coupling in the received signal vectors.…”

Calculation of beamforming for the HF radar with the two-element crossed-loop/monopole antenna array

“…[1][2][3][4][5][6] It can measure the ocean surface current, wind, and wave using high frequency (HF) (3-30 MHz) electromagnetic waves, which can propagate along the ocean surface. [7][8][9][10][11][12][13][14][15][16][17] Among these applications, wave measurement is a developing application which has been studied by many researchers, and intensive investigations have been done for decades. [8][9][10][11] The crossed-loop/monopole antenna [4,8], which is a compact antenna system, was first used by the coastal ocean dynamics applications radar (CODAR).…”

Design of a compact 4-port MIMO antenna system

“…Another way to isolate highly-coupled monopole antenna elements is based on the mode-decomposition method, in which a multiport network using 90° or 180° hybrid couplers is inserted between the antennas and their feeding ports [10]. Alternatively, some compact networks consisting simple microstrip ring-like structure in [11,12] are proposed to enhance the port isolation between three closely spaced antennas. Researches also show that the passive and lossless decoupling and matching networks can be used to transform the coupled antenna ports into independent and matched ports.…”