A logarithmic amplifier and Hilbert transformer for optical single sideband

Chromatic dispersion is the pulse spreading that occurs during transmission through optical fiber and is due to the non-constant delay of fiber with wavelength. Gigabit optical communication systems require some method of dispersion compensation. Optical single sideband (OSSB) is commonly used to transmit narrow-band signals in order to avoid power fading due to dispersion. However, in the absence of special optical filters, a broadband Hilbert transformer and logarithmic amplifier are required in order to generate OSSB for baseband gigabit data signals. This thesis describes the development of unique gigabit logarithmic amplifier and Hilbert transformer integrated circuits.; The Cherry-Hooper amplifier with emitter follower feedback is introduced as a gigabit amplifier building block. This circuit is ultimately used to design a broadband logarithmic amplifier for OSSB. The log amplifier architecture is developed using a novel design procedure, with proof of a logarithmic response. A Hilbert transformer integrated circuit is developed based on non-integrated Hilbert transformer designs by previous researchers. It uses Q-enhanced on-chip LC transmission lines. The log amplifier and Hilbert transformer designs were fabricated as integrated circuits, and their performance is verified through measurements of the circuits.; Simulation results of an OSSB system are described and show that the above mentioned circuits enable an OSSB system with immunity to dispersive power fading. Actual OSSB transmitters were assembled and measured OSSB optical spectra are presented for 5 and 10 Gb/s broadband signals and a 1.9 GHz narrow-band signal.