We review the development of thin. broadband. E-shaped microstrip patch antennas for high-speed (IEEE 802.11a) wireless communication systems operating in the 5.0 - 6.0 GHz frequency range. These antennas may be. used in low-profile wireless communication devices such as wireless network adaptor cards in the PCMCIA (also known as PC or Cardbus) format. Importantly, most of these antennas have a height that can be accommodated inside a wireless device as thin as 5mm thickness. Two different twin antenna configurations are also been discussed. The first configuration has two closely spaced similar antennas that can be independently used for transmitting and receiving. It can also be used for space diversity. The second is a diversity antenna pair that provides both polarization and space diversity. In all cases. the reflection at the antenna input is <-10 dB within the two IEEE 802.11a bands (i.e. 5.15 - 5.35 GHz and 5.725 - 5.825 GHz) and the isolation between the two antennas is > 20 dB in the same frequency bands.