Within advanced driver assistance systems, long-range radar devices with a frequency around 77 GHz are widely used. They have several advantages for automotive use, e.g. the wide bandwidth available improves accuracy and object resolution, combined with small antennas and limited interference with other systems due to atmospheric absorption. Nowadays, these sensors must provide better separation of objects and elevation estimation, translating to a higher angular and velocity resolution, which will be enabled by utilizing cascaded, off-the-shelf, radar front-end devices. In order to guarantee precise beam forming, all modules need to be synchronized. For the distribution of these signals, which are in the range of 20 GHz, optical technologies are of great advantage. They are lightweight, show low loss, are insensitive to electromagnetic interference and have the capability to be integrated. Within the proposed system, the electrical synchronization signal from a central master chip is transferred to the optical domain by a Mach-Zehnder modulator, amplified by an EDFA and distributed with an optical splitter to 4 separate modules. O/E conversion is carried out by a photodiode. Long time stable operation over a wide temperature range is ensured by an external bias voltage regulation of the modulator. First results of the complete system show improved accuracy and object resolution of the targets. The already space-saving design could be made even more compact with special integrated photonic devices. In addition, the realization of a complete optical radar, where the radar signals and echoes are transmitted with optical fibers, would be possible.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.