Continuous Wave Radio-Frequency Gain for opitcal link (transmitter+fiber+receiver)¶

A CW RF signal is generated with the Keysight N9310A Signal Generator. This signal is provided to the optical transmitter which converts it into an optical signal which intensity is modulated by RF carrier. The optical recevier converts the optical signal back to an RF CW signal. This signal is measured on the FSV spectrum Analyzer.

The gain is measured as : Gain = RF POWER [dBm] Optical Receiver Out - RF POWER [dBm] Optical Transmitter In.

Gain Linearity¶

Optical link overall response is linear within its operating input power dynamic : optical transmitter and receiver are both linear. Low signal distortion is expected.

Figure 1. RF Gain Linearity of Optical Link.

Frequency Response¶

Optical link frequency response has a shape of a low path filter : the 3 dB cutoff frequency is above 2300 MHz. Thus, the optical link is meeting its specification and is able to support the total IF band.

Figure 2. RF frequency respone.

As they are lossy coaxial cables to connect signal generator to the optical transceiver and optical receiver to spectrum analyzer, this losses have be to taken into account.