Design of a Compact High Isolation 4-Element Wideband Patch Antenna Array for GNSS Applications

Abstract

This work presents a compact (125 mm diameter) wideband four-element antenna array with a high isolation level for Global Navigation Satellite System (GNSS) anti-jamming applications. The array consists of four identical right hand circularly polarized (RHCP) single feed rectangular patch antennas that can cover BeiDou B1 band (1559.05 -1563.15 MHz), GPS L1 band (1563 -1587 MHz), Galileo E1 band (1559 -1591 MHz), and GLONASS G1 band (1593 -1610 MHz). The proposed array has a wide frequency bandwidth of 100 MHz (1.55 -1.65 GHz) with an axial ratio of less than 3 dB. The patch antenna elements are designed on a substrate that has a high dielectric constant to achieve a compact size. The size of each patch element is only 32 x 32 x 5.08 mm 3 . These patches are placed along the circumference of a circular aluminium ground plane of 125 mm diameter and 1.5 mm thickness in a 2x2 symmetrical arrangement. The edge-to-edge distance between the opposite patch elements is only 48 mm while for the adjacent elements the separation is only 27 mm. A microwave absorber material is employed to achieve an extremely low mutual coupling level over a wide frequency range (1.55 -1.65 GHz) within a compact form factor. The proposed design achieves a mutual coupling of less than -20 dB within a compact overall form factor of 125 mm diameter over the entire band of interest. The simulated and measured results of reflection co-efficient, mutual coupling, null steering, null depth, and radiation pattern show that the proposed antenna array is an excellent choice for multiband GNSS applications.INDEX TERMS High isolation, anti-jamming, circularly polarized, wideband antenna.

A High Efficiency and Low Mutual Coupling Four-element Antenna Array for GNSS Applications

“…Moreover, the rotational symmetry also helps in packing more antennas within a confined area. This design arrangement is also helpful in achieving better circular polarization (CP) and creating nulls for the anti-jamming capability [7]. The patches have their corners diagonally truncated to attain CP which is essential for GNSS antennas.…”

“…Each port comprises a feeding pin which is surrounded by teflon and an outer conductor that encapsulates the whole assembly. Owing to a symmetrically rotated configuration, the ports are given a phase shift of P 1 = 0 • , P 2 = 90 • , P 3 = 180 • , and P 4 = 270 • [7]. Fig.…”

“…Recently, microwave absorber materials have also been utilized to enhance the isolation level in GNSS arrays as in [7], and a 9.525 mm high MT-30 material is employed to enhance the isolation level above 20 dB. In [8], a 3.175 mm MT-30 material has been used in combination with a DGS for isolation enhancement to up to 25 dB.…”

Design and Study of a Microstrip Patch Antenna for GPS Application

“…Several microstrip patch antenna are presented in the literature for GPS applications [15][16][17][18][19][20][21][22][23]. [17] proposed an antenna for a GPS system based on an open-loop resonator, a split rectangular slot, and a stub at the non-radiating edge to generate three operating bands.…”

“…[17] proposed an antenna for a GPS system based on an open-loop resonator, a split rectangular slot, and a stub at the non-radiating edge to generate three operating bands. Awais et al [18] use four-element antenna array for the proposed antenna for a navigation satellite system. It is an assembled of 4 single patch antenna elements.…”