Tapered Unit Cell Control of a Sinusoidally Modulated Reactance Surface Antenna

A design procedure for synthesizing the desired beam pattern of the sinusoidally modulated reactance surface (SMRS) antenna is proposed. This methodology is a type of aperture tapering technique, where cosine distribution of aperture illumination was applied to the SMRS antenna. The unit cell of the SMRS antenna allows control of the leakage constant while keeping phase constant almost constant value in some allowable surface impedance modulation range; this characteristic provides the aperture amplitude tapering technique to the SMRS antennas. To verify this proposed concept, a prototype SMRS antenna composed of nine tapered unit cells was implemented using a printed circuit board process. The designed antenna radiates at 35° off broadside at 10 GHz. We obtained 16.6 dBi of measured antenna gain and the normalized sidelobe level was about -14.33 dB.