This study presents a wearable textile higher‐mode microstrip patch antenna (HMMPA) that has been designed to radiate omni‐directionally at 2.4 GHz Industrial Scientific and Medical (ISM) band. Emphasis is given to the fabrication process of the textile vias with conductive sewing thread that plays an important role in generating the optimal mode for on‐body radiation. The embroidery technique enabled a side‐fed low‐profile antenna which could be placed directly against the body. The proposed textile HMMPA antenna performance is compared with a probe‐fed HMMPA antenna fabricated with rigid copper radiating parts, for both free space and on‐body conditions. The on‐body antenna performance has been tested by performing near‐field measurements of the antenna on a full‐body specific anthropomorphic mannequin phantom in an anechoic chamber. Results show that the proposed textile HMMPA antenna with vias made from conductive thread can radiate on‐body with good efficiency while minimising the radiation in the broadside direction.

This study proposes an electronically switched parasitic array radiator (ESPAR) antenna at 5.9 GHz to meet the intelligent transportation systems standards. This antenna offers pattern switching capability with three distinct radiation patterns, i.e. one quasi‐omni and two directives in opposite directions, by controlling the mutual coupling at the parasitic elements with PIN diode switches. A considerable gain increase of up to 3 dB is achieved in the directive mode, while maintaining a satisfying impedance matching between the switching states. The compact ESPAR antenna is printed on a low loss Rogers dielectric and consists of one active and two parasitic monopoles. S11 and radiation pattern results are presented, derived from both simulations and measurements, exhibiting a close agreement.

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