Efficient microwave frequency conversion using photonic link signal mixing

Optoelectronic RF signal mixing using an electroabsorption waveguide as an integrated photodetector/mixer

“…When the EA waveguide was biased at the third-order null point of the device photocurrent versus dc bias curve (0.44 V), the up-converted RF signal power was reduced by 3 dB, but the suboctave SFDR was measured at 120.0 dB-Hz . At the third-order null point, the IMD due to the third-order input power dependence becomes null, making the IMD depending on the next order, which is the fifth-order [4], [12]. The bias sensitivity for the third-order null point was 10 mV.…”

“…Decreasing the coupling loss from the fiber to the EA waveguide is another approach, which also increases . When this EA waveguide was used as a modulator/mixer and the converted signals were transmitted through the optical fiber as in [4]- [6], the conversion gain was reduced to −27.8 dB. The 8.9-dB gain reduction is due to the fact that the responsivity of the remote detector, at the end of the fiber link combined with the EA waveguide insertion loss, , was much smaller than that of the EA waveguide , i.e., .…”

“…Many of the conversion schemes take advantages of the optical local oscillator (LO), which is simpler than the electronic LO at high frequency, and has less phase noise [3]. There have been several attempts to achieve low conversion loss and large spur-free dynamic range (SFDR) for frequency-converted photonic links [4]- [6]. In [5], monolithic series Mach-Zehnder modulators were used with very high optical LO power (350 mW) to achieve link conversion gain (defined as the ratio of the output converted RF power to the input RF power) of 17 dB and 3.3 dB, with and without impedance matching, respectively.…”

“…Unlike previous approaches [1], [2], [4]- [6], frequency converted electrical RF signals from an EA waveguide, operating as an OEM, are generated and made available for subsequent signal processing. The down-converted RF signal can be sent through conventional electrical cable that has low attenuation at low frequency, or processed locally near the antenna using usually inexpensive electronics.…”

Millimeter-Wave Radio over Fiber System for Broadband Wireless Communication

“…Due to the characteristics of mm-wave, the electrical delivery of mm-wave wireless signals over a long distance is not feasible. Many research works have been done to transmit mm-wave over the fiber-optic links, which exploit the advantages of both optical fibers and mm-wave frequencies to realize broadband communication systems and contribute a lot to the development of mmwave Radio over Fiber (RoF) systems (Sun et al, 1996;Braun et al, 1998;Kitayama, 1998). Figure 2 gives the architecture of mm-wave RoF system.…”