Photonic generation of arbitrarily phase-modulated microwave signals based on a single DDMZM

Abstract

We propose and demonstrate a compact and cost-effective photonic approach to generate arbitrarily phase-modulated microwave signals using a conventional dual-drive Mach-Zehnder modulator (DDMZM). One arm (arm1) of the DDMZM is driven by a sinusoidal microwave signal whose power is optimized to suppress the optical carrier, while the other arm (arm2) of the DDMZM is driven by a coding signal. In this way, the phase-modulated optical carrier from the arm2 and the sidebands from the arm1 are combined together at the output of the DDMZM. Binary phase-coded microwave pulses which are free from the baseband frequency components can be generated when the coding signal is a three-level signal. In this case, the precise π phase shift of the microwave signal is independent of the amplitude of the coding signal. Moreover, arbitrarily phase-modulated microwave signals can be generated when an optical bandpass filter is attached after the DDMZM to achieve optical single-sideband modulation. The proposed approach is theoretically analyzed and experimentally verified. The binary phase-coded microwave pulses, quaternary phase-coded microwave signal, and linearly frequency-chirped microwave signal are experimentally generated. The simulated and the experimental results agree very well with each other.

Photonic generation of phase-modulated microwave signals

“…It suffers from stability problem in real-world applications. We have reported a compact and cost-effective approach to generate arbitrarily phase-modulated microwave signal using a conventional DDMZM [11], including the generation of pulsed phase-coded microwave signal, quaternary phase-coded microwave signal, and linearly frequency-chirped microwave signal.…”

“…3, an optical carrier from a LD is launched to a DDMZM, one arm (arm1) of the DDMZM is driven by a sinusoidal microwave signal whose power is optimized to suppress the optical carrier, while the other arm (arm2) of the DDMZM is driven by a coding signal. In order to suppress the optical carrier on arm1, the power of the sinusoidal microwave signal has to be adjusted to let the DDMZM has a phase modulation index of 2.4 rad [11]. The phasemodulated optical carrier from arm2 and the carrier-suppressed optical signal from arm1 are combined at the output of the DDMZM, as shown in Fig.…”

Generation of a frequency-quadrupled phase-coded signal using optical carrier phase shifting and balanced detection

“…However, the schemes based on the polarization modulation are usually complicated and costly due to the use of multiple modulators. A phase-coded signal can also be generated based on the optical carrier phaseshifting technique [14][15][16][17]. In this method, a modulator with two parallel branches is usually needed, such as a dual-drive Mach-Zehnder modulator (MZM) [14,15], a quadrature phase shift-keying (QPSK) modulator [16], or a dual-polarization integrated modulator [17].…”

“…A phase-coded signal can also be generated based on the optical carrier phaseshifting technique [14][15][16][17]. In this method, a modulator with two parallel branches is usually needed, such as a dual-drive Mach-Zehnder modulator (MZM) [14,15], a quadrature phase shift-keying (QPSK) modulator [16], or a dual-polarization integrated modulator [17]. In the modulator, one branch is driven by an RF signal to generate two optical sidebands with the optical carrier suppressed, while another branch is driven by a coding signal to control the phase shift of the optical carrier.…”

Photonic generation of background-free millimeter-wave ultra-wideband signals (Invited Paper)

“…For UWB signal transmission, signal modulation is also very important. We have reported binary phase modulation of an MMW-UWB pulse using cascaded modulators [21] or a single modulator [22] . To generate a binary phase modulated MMW-UWB pulse, a three-level electrical pulse has been used.…”