Textured Surface Assisted Active Antenna Performance

In this paper the possibilities associated with augmenting the properties of millimeter wave active antennas performing reflection amplifier or short range radar action by using the properties of a 2D metamaterial textured surface are discussed. The objective here is to effect simultaneous improvements in antenna gain and reduction of un-modulated backscatter from the environment in which the module is housed. A reflection amplifier module with up to 14 dB gain at 21 GHz is described which is capable of either direct detection or modulated backscatter of amplitude modulated incident signals. A detection sensitivity of up to -75 dBm has been achieved. In addition the module, when suitably biased, can be made to operate as a short range radar with up to -120 dBm sensitivity in a 30 Hz bandwidth. An ultra thin meta material based absorber with -16 dB reflection loss provides the means for backscatter reduction which is compliant with the planar nature of the module. Further the inclusion of the absorber is shown to increase the gain of the module by 4 dB.