A novel frequency 12-tupling optical millimeter-wave (mm-wave) generation using two cascaded dual-parallel Mach–Zehnder modulators (DP-MZMs) without an optical filter is proposed and demonstrated by computer simulation. By properly adjusting the amplitude and phase of radio frequency (RF) driving signal and the direct current (DC) bias points of two DP-MZMs, a 120 GHz mm-wave with an optical sideband suppression ratio (OSSR) of 25.1 dB and a radio frequency spurious suppression ratio (RFSSR) of 19.1 dB is shown to be generated from a 10 GHz RF driving signal, which largely reduces the response frequency of electronic devices. Furthermore, it is also proved to be valid that even if the phase difference of RF driving signals, the RF driving voltage, and the DC bias voltage deviate from the ideal values to a certain degree, the performance is still acceptable. Since no optical filter is employed to suppress the undesired optical sidebands, a high-spectral-purity mm-wave signal tunable from 48 to 216 GHz can be obtained theoretically when a RF driving signal from 4 to 18 GHz is applied to the DP-MZMs, and the system can be readily implemented in wavelength-division-multiplexing upconversion systems to provide high-quality optical local oscillator signal.

An exact analytical expression of the signal-to-noise ratio (SNR) for an intersatellite microwave photonics link with an optical preamplifier is derived considering the signal fade caused by the pointing errors of the transceiver, and an optimized model for laser output power and direct current (DC) bias phase shift of the Mach–Zehnder modulator is established. It is shown that, given the desired SNR and the root mean square (rms) random pointing jitter, an optimal DC bias phase shift exists that minimizes laser output power. The effects of the optical preamplifier parameters on the minimum laser output power and optimal DC bias phase shift are also examined. Numerical results show that the preamplifier noise figure determines the minimum laser output power needed to achieve the desired SNR but affects the optimal DC bias phase shift little. For a SNR of 20 dB, doubling the preamplifier noise figure results in a 6.36 dB increase in minimum laser output power for rms pointing jitter of 0.4 μrad.

An optical preamplifier is utilized to improve the signal-to-noise and distortion ratio (SNDR) of intersatellite microwave photonic links employing a Mach–Zehnder modulator under dual-tone modulation. The resulting SNDR at an appropriate direct current (DC) bias phase shift is additionally investigated without small-signal approximation in order to optimize the performance of all the links. It is observed that the most limiting factor degrading the SNDR performance is changed, and the fundamental power is seen to increase more compared with the power of third-order intermodulation (IM3) plus noise due to the optical preamplifier. Thus, SNDR can be improved with respect to the case of a nonoptical preamplifier. For the preamplifier gain of 20 dB and noise figure of 3 dB, an increase of about 24 dB in optimum SNDR is accessible. In addition, the optimum DC bias phase shift is found to be insensitive to the preamplifier gain and noise figure, while the optimum SNDR is sensitive to the preamplifier gain and noise figure.

A microwave photonic scheme for multi-functional radio over fiber based in-band full duplex communication links to realize deep self-interference cancellation, long range transmission, and efficient signal recovery is proposed. In the proposed scheme, double sideband modulation helps avoid applying electrical couplers or optical filters and is beneficial to improve the frequency conversion efficiency. By virtue of the intermediate frequency signal amplitude regulation mechanism induced by fiber dispersion, the conditions of dispersion induced power fading compensation, amplitude matching, and phase reversion between self-interference and reference signals can be satisfied through joint DC bias tuning. The high precision delay matching in the optical domain is advantageous to the deep self-interference cancellation performance in a wide frequency range compared to its electrical counterparts. Furthermore, the deterioration of signal quality and self-interference cancellation performance caused by fiber dispersion is avoided. Experimental analyses show that a single tone signal in a wide frequency range of 2–20 GHz can be cancelled over 60 dB. A broadband signal with bandwidth of 50 MHz in the C-band, X-band, and K-band can be cancelled over 35 dB. Furthermore, the recovery performance of the signal of interest with different modulation formats and different signal to interference ratios is investigated, showing high quality signal transmission and efficient signal recovery. The capability of dispersion induced power fading compensation is also verified, and the spurious-free dynamic range is measured to be 88.47dB⋅Hz^2/3.