A dual band feed structure for slot and notch antennas

The design of a multi-band microstrip to slot line junction structure was described in this article. The structure uses multiple crossings of the microstrip line over the slot line. Each crossing excites a resonant frequency of the slot or notch antenna, thus enabling multi-band operation of the slot or notch antenna. The design was applied to a 3 antenna system that operates in the 2.4 GHz and 5.2/5.8 GHz bands for IEEE 802.11 a/b/g/n.