Photonic-based reconfigurable microwave frequency divider using two cascaded dual-parallel Mach-Zehnder modulators

Abstract

A photonic-based reconfigurable microwave frequency divider using two cascaded dual-parallel Mach-Zehnder modulators (DP-MZMs) is proposed. The first DP-MZM is driven by the input microwave signal, whereas the second DP-MZM is incorporated in an optoelectronic oscillator (OEO) loop and driven by the feedback signal. By properly setting the working conditions of the two DP-MZMs, the frequency of the input microwave signal is divided and the frequency-divided signal will oscillate in the OEO loop, with a tunable frequency-division factor determined by the bias conditions of the DP-MZMs. An experiment is performed. The reconfigurable microwave frequency divider is demonstrated with a frequency-division factor of 1.5, 2.5, 2, or 3, and the phase noise of the frequency-divided signals is also evaluated, which has an improvement of 3.22, 7.60, 5.80, or 9.49 dB at 10-kHz frequency offset, respectively, compared with that of the input microwave signals.

Microwave Frequency Dividers With Reconfigurable Fractional 2/N and 3/N Division Ratios

“…The power ratio of the 1 st and 3 rd order sidebands was found to be 29 dB. Since the 1 st and 3 rd order sideband powers are proportional to J1(RF) 2 and J3(RF) 2 respectively, the modulation index RF is 0.91. The DFB laser temperature was fixed at 25 C and its forward bias current was increased to 47.7 mA to obtain two frequency components with a separation of 12 GHz between the two regenerated 1 st order sidebands at ±18 GHz away from the optical carrier.…”

“…The SL forward bias current can be adjusted to generate n number of equally spaced optical frequency components between the two regenerated ±1 st order sidebands at the SL output. When n is an even integer, the SL output electric field can be written as (2) where A±k1(m) and ±k1(m) are the amplitude and phase of the optical frequency component at fc±k1(m)fRF, and k1(m)=(2m+1)/(n+1). When n is an odd integer, the SL output electric field can be written as (3) where A±k2(m) and ±k2(m) are the amplitude and phase of the optical frequency component at fc±k2(m)fRF, and k2(m)=(2m+2)/(n+1).…”

“…Photonics-based microwave frequency dividers with a tunable frequency division ratio have been demonstrated via the regenerative technique [1], [2], the injection locking technique [4], [5] and the optically injected semiconductor laser technique [8]. Almost all of them are focused on realising frequency division with a tunable integer frequency division ratio so that the frequency of the output RF signal is 1/N times the input RF signal frequency, where N is an integer.…”

“…However, this increases the system complexity, size and cost. To the best of our knowledge, until now there is only one reported microwave photonic structure that can realise microwave frequency division with both integer (1/2 and 1/3) and non-integer (2/3 and 2/5) division ratios [2]. This frequency divider is constructed using the regenerative technique through an optoelectronic oscillator (OEO) loop, which involves a number of electrical components including an electrical phase shifter, electrical amplifiers and electrical couplers.…”

Photonic‐assisted one‐third microwave frequency divider

“…It can be seen from Figure 1 that the frequency divider is implemented by a DPMZM and an MZM connected in series. To our knowledge, three microwave frequency dividers based on cascaded modulators have been reported [6,7,9], but all require using an EPS to control the round-trip phase for generating a frequency-divided signal.…”