A compact MIMO antenna system for WLAN with enhanced isolation

Abstract

X resistor, coaxial line C5 1/90 obtained with a dual six-port network analyzer. The calibration elements were the air (open standard), the short standard, and match load (Agilent 85070D kit).The measurement results of both reflection and transmission coefficients are relatively close to ideal values. For improving the results, calibration is required to obtain a well-conditioned solution. CONCLUSIONA dual-band six-port reflectometer has been designed and manufactured to measure the reflection coefficients of two-port networks at the frequency of 0.915 GHz and 2.45 GHz. An ADS simulation and experimental measurements were performed to show some significant features of the dual-band six-port network analyzer in a wide frequency range of 2.2-2.6 GHz and 0.8-1 GHz. Six-port output powers are read using eight diode detectors and all four scattering parameters related to DUT are measured using the expressions given in section 2. Measurement results for different loads are compared with ideal values that are in good agreement in terms of phase and magnitude of the reflection coefficients. Using this technique, we decreased the cost and complexity of devices. In addition, it is well suited for portable application testers outside the laboratory.ABSTRACT: A compact multiple-input and multiple-output (MIMO) monopole antenna system for WLAN (2.45 GHz) with enhanced isolation is proposed. The proposed MIMO antenna system consists of two identical monopole antenna elements operating at the same frequency of 2.45 GHz. In order to improve the isolation performance, each antenna element is individually placed on one side of the substrate. With meandered strips, the size of the proposed antenna system is dramatically decreased to 15.9 mm 3 9 mm. The isolation between the two antenna elements exceeds 18.29 dB by employing the orthogonal polarization diversity technique and the physical isolation method. The 10 dB bandwidth of the proposed antenna system reaches 120 MHz, which is wide enough for the practical application. Measured results are in close agreement with the simulated ones.

Ultra‐compact 4‐port DR antenna for multi‐input multi‐output standards

“…In fact, the main difficulty in designing compact MIMO antennas is to achieve high levels of isolation between adjacent antennas while maintaining excellent radiation efficiency. In this area, several useful solutions to get proper isolation levels and compact MIMO structures are reported . In, the miniaturization technique is introduced to achieve good isolation, for two‐coupling element antennas designed for MIMO‐4G systems.…”

“…Moreover, a decoupling network for a coupled two‐element array is also proposed in Reference . In Reference , a 2‐port MIMO antenna for WLAN applications is suggested by using the orthogonal polarization diversity, and physical isolation techniques. A 2 × 2 and 2 × 4 MIMO antennas are introduced in Reference , which consist of patch antennas loaded with complementary split‐ring resonators for antenna miniaturization.…”

“…In this area, several useful solutions to get proper isolation levels and compact MIMO structures are reported. [3][4][5][6][7][8][9][10][11][12] In, 3 the miniaturization technique is introduced to achieve good isolation, for two-coupling element antennas designed for MIMO-4G systems. Another technique based on the reduction of mutual coupling between antenna elements by using metamaterials is presented in.…”