Generation of frequency 16-tupling millimeter wave using remodulation technique without filtering based on dual-parallel polarization modulator

Abstract The rapid evolution of 5G and emerging 6G technologies demands high-frequency millimeter-wave (MMW) signal generation to meet growing requirements for high-capacity, low-latency communications. However, current frequency multiplication techniques often require complex filtering and high modulation indices, introducing distortion and limiting system performance. A scheme is proposed based on a dual-parallel polarization modulator (DP-PolM) to generate a frequency 16-tupling MMW without a filter. The scheme can be divided into two parts. In the first part, the RF drive signal of 8 GHz is used to drive DP-PolM1. The MMW of 32 GHz can be generated by controlling the modulation index (MI) and the phase difference between the upper and lower arms of DP-PolM1 and the angle of the polarizer (Pol). In the second part, the MMW generated in the first part is used as the remodulation signal to drive the DP-PolM2, and the output power of the optical carrier can be adjusted to produce a 128 GHz MMW with optical sideband suppression ratio and radio frequency spur suppression ratio of 55.02 dB and 46.25 dB, respectively. In addition, the stability of the remodulated signal and the generated frequency 16-tupling MMW signal under different optical carrier power and the MI are analyzed. The results show that the system can generate a frequency of 16-tupling MMW when the optical carrier power, MI offset, phase difference of the RF local oscillator signal driving DP-PolM, and polarization controller angular deviation are less than <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mrow> <mml:mo>±</mml:mo> <mml:mn>44</mml:mn> <mml:mi mathvariant="normal">%</mml:mi> </mml:mrow> </mml:math> , <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mrow> <mml:mo>±</mml:mo> <mml:mn>38</mml:mn> <mml:mi mathvariant="normal">%</mml:mi> </mml:mrow> </mml:math> , 40°, and 26°, respectively. Compared with existing schemes, the proposed approach offers a simpler and more efficient solution for high-frequency MMW generation by removing the need for complex filtering and achieving better performance with a smaller MI. It shows strong potential for addressing challenges in future 5G and 6G communication systems.