Photonic Generation of Millimeter-Wave Signals With Frequency-Multiplying and Tunable Phase Shift

A novel photonic approach for generating a frequency-septupling or frequency-nonupling millimeter-wave (mm-wave) signal with tunable phase shift is proposed. Two fourth-order sidebands and an optical carrier are generated by using a dual-parallel Mach-Zehnder modulator (DPMZM). An optical bandstop filter (OBSF) is used to filter out optical carrier and a Mach-Zehnder interferometer (MZI) is employed to separate the +4th-order sideband and the −4th-order sideband. Then the −4th-order sideband is modulated by an optical phase modulator (PM), and the phase of the −4th-order sideband can be controlled by changing the dc voltage that drives the PM. The +4th-order sideband is modulated by the second DPMZM, then a +3rd-order sideband or +5th-order sideband is generated by controlling the dc voltage that drives the main-MZM of the second DPMZM. After an optical coupler and a photodiode (PD), a frequency-septupling or frequency-nonupling mm-wave signal with tunable phase shift is gotten. A simulation experiment is performed, and tunable 360-degree phase shift is realized, and the amplitude variation of the generated mm-wave signal is less than 0.2dB.