Qualop Systems Corporation

C-cor.net Corporation

Ching Ho

Yue-Syan Jou

Nelson M Shen

Peter Wang

Chun-Meng Su

Yong Cheng Tu

Sunny K Hsu

Abraham Y Jou

Gengxin Li

A predistortion circuit and method provides signals to oppose and cancel an anticipated phase and frequency distortion in a coupled electrical system. The predistortion circuitry includes first and second subcircuits which include opposing diodes, providing 180 degree out-of-phase and in-phase signals to produce second, third and higher order predistortion outputs.

Linearization circuits and methods

An optical receiver communication system converts optical signals modulated by analog or digital waveforms to RF signals. The optical receiver contains an automatic level control circuit to adjust the electronic gain of the system across a broad bandwidth spectrum. Two impedance matching circuits are designed using broad band matching technique to expand the bandwidth for increasing the maximum receivable frequencies to 1 GHz. A RLC impedance matching circuit forms a resonant combination to maintain .+-.1 dB fluctuation between the low-and-high-frequency limits of the bandwidth, and a 75.OMEGA. impedance matching circuit creates a 180.degree. phase shift between outgoing and incoming signals to ensure low return loss.

Universal optical signal receiver

An optical receiver communication system converts optical signals modulated by analog or digital waveforms to RF signals. The optical receiver contains an automatic level control circuit to adjust the electronic gain of the system accordingly across a broad bandwidth spectrum. Two impedance matching circuit are designed using broad band matching technique to expand the bandwidth for increasing the maximum receivable frequency to 1 GHz. A RLC impedance matching circuit forms a resonant combination to maintain .+-.1 dB fluctuation between the low-and high-frequency limits of the bandwidth, and a 75 .OMEGA. impedance matching circuit creates a 180.degree. phase shift between the outgoing and the incoming signal for low return loss.

An optical isolator system and method improving the manufacturability of the system, including fabricating a unitary tubular optical isolator system in two parts which are soldered together. The tubular system includes an internal disk to protect the isolator from heated solder during joinder of containment portions. The optical isolator system includes tubes to space polarizer, analyzer, and isolator portions.

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San Jose, CA, United States of America

Ching Ho