  This paper proposes a novel method to enhance the performance of the
modulator for fifth-generation wireless communication (5G) by exploiting
modulation instability (MI). We show that MI can reduce the bias voltage of the
modulator ($V_\pi$) by generating carrier side-band gain, and increase the
modulation BandWidth (BW), resulting in higher channel capacity, without
changing the modulator structure. In receive mode of the array antenna, where
the signal is very weak, high-frequency amplification is a high demanding
solution to mitigate coverage issue.
  We also present a developed microwave-photonic beamforming bit-controller
system for receiver-transmitter phased array antennas (PAAs), which are
essential for high-capacity wireless communications like 5G. We employ a
modulated frequency comb exploiting MI fiber to achieve an amplified true-time
delay (TTD) technique for wide-coverage PAA beamforming and show that it can
steer wideband high-frequency signal to a specific direction angle, avoiding
beam-squint.
