Ling Chuen Ong

Design of low-profile broadband dual-polarized integrated patch sub-array for X-band SAR payload on small satellite

A practical low-profile broadband dual-polarized patch sub-array is designed for highly integrated X-band SAR payload on small satellite with enhanced isolation, suppressed cross-polarization and reduced side-lobe level. The proposed sub-array is lightweight with low profile (due to its tile structure realized by multi-layer PCB process). The proposed sub-array has 14-dB operating bandwidths of 0.7 GHz for both H- and V-pol radiations with isolation above 40 dB. It achieves the realized gain of 15 dBi. The side lobe levels are below -20 dB. The cross-to-co polarization ratios are lower than -40 dB at the bore-sight maximum-gain direction.

Dual-polarized x-band microstrip sub-array with hybrid feed network for SAR payload on small satellite

This paper presents a low-profile wideband dual-polarized X-band microstrip sub-array for SAR payload on small satellite fed by a hybrid series/parallel network. The sub-array of 1×16 microstrip radiators, fully covers the targeted 9.65GHz band with 14dB bandwidths of 9.1–10.3GHz for V-polarization (VP) and 9.13–9.93GHz for H-polarization (HP). The isolation is better than 35dB. The average realized gains are around 17dBi for both polarizations. The side-lobe levels are −25dB for HP and −20.5dB for VP. The cross-polarization levels are above −35dB and within the HPBW scope.

Wideband Segmented Loop Antenna with Dual-Polarized Omnidirectional Patterns for Mobile Platforms

A wideband planar double-segmented loop antenna that can excite different modes with perpendicular polarized omnidirectional radiation patterns is designed for mobile platforms. The proposed antenna combines these resonant modes with adjacent resonant frequencies for wideband application. One of the modes is induced by the loop element itself and generates horizontally polarized radiation pattern. Meanwhile, the other mode generates vertically polarized radiation pattern when the ground plane is excited by the loop element and operates as a radiator. The measured results confirm that the antenna is capable of achieving wide bandwidth (10-dB return loss) from 2.1 to 2.9 GHz (the corresponding fractional bandwidth is 32%). The average total realized gain of the antenna is 2.75 dBi over the entire operating bandwidth.

Design of wideband planar loop antenna with two perpendicular modes for mobile platforms

In this paper, we present a wideband mobile antenna with two modes that can produce dual-polarized omni-directional radiation patterns using a segmented loop element. The two different modes are designed to operate at neighbouring frequencies to realize the wideband property. The segmented loop itself induces one mode and radiates H-polarized radiation pattern. In the meantime, the loop element excites the ground plane which operates as a radiator and radiates V-polarized radiation pattern. The results confirm that the proposed antenna covers the WiMAX and WLAN bands with a 10-dB impedance bandwidth of 0.74 GHz (2.12 GHz – 2.86 GHz). The mobile antenna achieves the average realized gain and radiation efficiency of 2.9 dBi and 84% over the entire operating bands, respectively.

A compact monopole fractal antenna for TV white space energy harvesting applications

In this paper, a compact monopole fractal antenna for the TV white space frequency band is designed and fabricated for energy harvesting applications. The monopole is designed by the combination of modified Giuseppe Peano fractal geometry and impedance steps and fabricated on a 1.6mm thick FR-4 substrate. The feeding circuit is designed to be a microstrip line with a semi-circular ground plane. The antenna resonates at 600MHz and shows omni-directional radiation patterns with a measured gain of 1.71dBi. A size reduction of 52% is achieved as compared to the conventional planar monopole antenna.