Conformal on-glass vehicle antennas at VHF

Previous work by the authors (see IEE Internat. Conf. on Antennas and Propag., vol.2, p.950, 1991) described the requirements for modelling a passenger vehicle and its rear-window heater when used as an unconventional receiving antenna for VHF broadcast reception. The complexity of the current distribution which results, both on the heater element as well as on the vehicle bodywork was discussed and the effects of this on the radiation patterns of various antennas were computed using the NEC 2 Moment Method code. Whereas it was realised that the glass substrate on which the antenna is mounted would alter its characteristics this effect was not quantified in that earlier study. Here they present the results of further research which, amongst other things, considers the effects of the glass on the performance of these antennas and includes comparative results from both the computer simulations and from an extensive measurement programme