Scan-phase antenna diversity for digital satellite radio (SDARS) in a single automotive side mirror

Abstract

The reception of satellite digital audio radio services (SDARS) by vehicular receivers with a single antenna is usually only possible using a rooftop mounting position due to very strict specifications by the service provider. In cars where rooftop mounting is not an option alternative mounting positions have to be found. In most situations a single receiving antenna is not sufficient due to shadowing, attenuation, and strict size constraints leading to small ground planes in these positions.A single side mirror is used for mounting a diversity antenna set which is combined with a scan-phase diversity system in the work described in this paper. Signal recordings of such a scenario are analysed statistically and compared for test drive data of a shadowed and a non-shadowed antenna positioning due to the driving direction. Measurement results of the audio availability in real Rayleigh-fading scenarios show that the diversity system outperforms a single standard antenna on the rooftop of a car in this new configuration even though the car's shadowing of the antenna is considered.

Automotive antenna diversity system for satellite radio with high phase accuracy in low SNR-scenarios

“…In multipath fading environments the use of several receiving antennas in combination with a scan-phase antenna diversity system has been shown, reducing audio mutes significantly compared with single antennas [12–14]. In [15,16] measurements are presented which prove that even at critical mounting positions – e.g. on the dashboard or in a single side mirror – our scan-phase antenna diversity achieves excellent improvements of audio availability compared with single antenna systems.…”

Vehicle Platform Effects on Performance of Flexible, Lightweight, and Dual-Band Antenna for Vehicular Communications

“…There is a lot of ongoing research on automotive antennas for Vehicle to Everything communications but most of the antennas are placed on the rooftop of the vehicle like in [1], [2], [3]. Antenna positions on a vehicle, similar to the mounting that is presented in this paper is used in [4]. The authors tested two dislocated antennas for satellite communications as a diversity antenna inside a vehicle's side mirror.…”

“…In contrast to [14], the antenna presented here is measured on automotive plastics on a real vehicle at an outdoor facility in order to investigate the effect of the vehicle body and the ground on the signal transmission and reception of a non-grounded antenna. Compared to [4], [6] and [7] the antenna presented here is dual-band, resonating at 975 MHz and 5.5 GHz. C-V2X applications use the 5.9 GHz.…”

“…The antenna suggested here, when measured alone resonates around 5.5 GHz but when placed on an automotive plastic the resonance shifts to 5.9 GHz. Also, compared to the [4] in Table 1 it is only one structure operating in two different frequencies and thus it is more compact. In addition, none of the antennas in Table 1 have been tested in a real environment with a ground and a whole vehicle body.…”