Leaky wave antenna with amplitude controlled beam steering based on composite right/left-handed transmission lines

[摘要] An antenna comprising two different composite right/left-handed transmissionline structures is proposed which enables easy beam steering at an operationfrequency of 10 GHz. The composite right/left-handed transmissionlines are based on planar, periodically arranged via free unit cells,implemented in microstrip technology. Both transmission lines exhibit theinfinite wavelength phenomenon which occurs at 9.72 GHz and9.89 GHz, respectively. Thus, operating the different leaky wavestructures at 10 GHz, radiation with azimuth angles of ±8°and ±17° can be achieved depending on the selected input port. Inorder to obtain a tunable main beam direction, the radiation patterns of bothstructures are superimposed by feeding them simultaneously. The influence ofeach guiding structure, and hence the direction of the main beam, can becontrolled via the feeding amplitude. As a result of this, the beam can besteered between ±17° with a gain of up to 10 dBi. The guidingstructures are arranged in parallel with a clearance of a=12.2 mmwhich is less than half of the wavelength in free space. This allows in afurther step the attachment of additional guiding structures in order toincrease the tunable angle range or creating an antenna array with a smallbeamwidth in the elevation plane without the occurrence of grating lobes. Anantenna prototype was fabricated and validated by measurements.

[学科分类] 电子、光学、磁材料