In this paper a novel microwave photonics beamformer device concept, for single side band (SSB) 40 GHz
modulated signals, is presented. The proposed device comprises tunable lasers, flat-top arrayed waveguide
gratings (AWG), a Mach Zender Modulator (MZM), an all-pass ring resonator and photodetectors. The device
can be produced as a photonic integrated circuit. The signals from the lasers (one for each beamformer radiant
element) are multiplexed by the first AWG, modulated, and passed through the all-pass ring resonator. The AWG
channel spacing and the ring resonator Free Spectral Range (FSR) are both set to be equal to 100 GHz. The signal
is demultiplexed by a second AWG and finally photodetected. By tuning each laser within its corresponding AWG
passband, the phase difference between the optical carrier and the 40 GHz microwave modulated signal for each
beamformer element can be controlled. The difference is determined by the phase response of the all-pass ring
resonator. A critical part of the design is the alignment between the resonances of the ring resonator and both
AWGs, but this can be alleviated by using a single AWG in fold-back configuration. The power provided to each
beamformer element is different due to the intrinsic non-uniform losses of the AWGs and the ring resonators, but
this can also be solved either by properly setting the lasers power, or by means of additional optical amplifiers.
The presented analysis is independent of the integration technology. In Silicon photonics, the AWGs and ring
resonator can be produced, while the (hybrid) integration of lasers, modulator, photodetectors (and eventually
amplifiers) is a challenge. The device can be monolithically integrated on semi-insulating InP technology.