Characterization of a D-Band Active Transmitarray System for Efficient Point-to-Point Links

We present the design and characterization of an innovative D-band transmitting antenna system. It comprises an active focal-plane array with two separate antennas which radiate two different signals, with adjacent bands, generated by an integrated circuit, and a flat discrete lens. The lens is designed to form a high-directivity broadside beam in both bands, i.e. from 139.3 GHz to 156.6 GHz. The use of two narrowband signals enhances the spectral efficiency and power consumption. Measurements show a remarkable improvement of transmitted power with respect to similar transmitters performing channel aggregation with guided components. The effective isotropic radiated power is higher than 25 dBm in a relative bandwidth of 11% and attains a peak value of 30.5 dBm. The measured radiation patterns are stable with frequency in each of the two sub-bands. The estimated antenna gain of the system (about 26 dBi) is in tight agreement with numerical data.