A RF-DAC Based 40Gbps PAM Modulator with 1.2pJ/Bit Energy Efficiency at Millimeterwave Band

A PAM-4 modulator is designed and fabricated in a 0.25µm indium phosphide (InP) double heterojunction bipolar transistor (DHBT) technology. The modulator is verified to have a 3-dB bandwidth of 60–90 GHz and a peak output power of -5 dBm at 75 GHz. This modulator can support 40 Gbps data transmission with a bit error rate of 3.7×10-6, the energy efficiency is better than 1.2 pJ/bit. This modulator is suitable for application such as low power, short range, ultra high data rate wireless communication.