Hidden antennas for vehicles

The introduction of new telematics and broadcast systems into vehicles has led to a requirement for multiple antennas that can be hidden from view. This paper commences by presenting the results of simulations to identify the components of a car's structure that influence the radiation pattern of a printed VHF antenna on the rear windscreen. Two dual-band antenna designs are then presented for operation in the 900 and 1800 MHz telephone bands. The first is a planar inverted-F antenna that can be concealed in the bumpers, the second a hybrid structure based on the top-loaded monopole principle and mounted beneath the vehicle's roof.