Semi-helical bondwire on-chip antenna

This paper describes the design and performance of a semi-helical antenna fabricated on a high resistivity silicon substrate. The helical structure is realized by traces of bondwires. By adjusting the looping profile of the bondwires, various resonant frequencies can be obtained. Due to the helical structure and the inductance loading effect, the antenna is significantly miniaturized. In this paper, a semi-helical bondwire antenna resonating in the 5 GHz ISM band was designed and fabricated to demonstrate the idea. The size of the fabricated antenna is 5.30 mm × 2.30 mm and this corresponds to 0.092λ0 × 0.040λ0. Measurement results show good agreement with the simulation model. The fabricated antenna resonates at 5.2 GHz and has an impedance bandwidth of 220 MHz. The antenna has a measured gain of 0.96 dBi and a measured radiation efficiency of 40.3 %. The proposed antenna is therefore potentially suitable for IEEE 802.11a applications.