Abstract: Disclosed herein are circuits and methods for reducing a thermally dependent gain swing. Exemplary embodiments include a resonant notch filter in parallel with a thermistor.

Abstract: The present invention is directed towards an optical receiver including an open loop automatic gain control (AGC) circuit. Optical signals received by the optical receiver are converted to electrical signals via a photodiode. The electrical signals are subsequently amplified through an input and an output amplifier stage. The amplified signal is then converted to RF signals and provided to an output port for further transmission. Concurrently, the AGC circuit senses the input optical power level at the input photodiode. The input optical power level is compared with a reference voltage, thereby providing a difference voltage. The difference voltage is applied to input and output amplifier stages for correcting the electrical signals to ensure a constant output power level.

Abstract: Disclosed herein are circuits and methods for reducing a thermally dependent gain swing. Exemplary embodiments include a resonant notch filter in parallel with a thermistor.

Abstract: A device includes an equalizer and an amplification chain in a transmitter or a receiver. The device comprises an equalizer for equalizing an input signal. The equalizer is positioned between two amplifier stages, which amplify the signal. The positioning of the equalizer greatly improves the noise figure and the distortion figures on the output signal. The device can be packaged into an integrated circuit for greater performance figures.

Abstract: A device includes a differential equalizer that is suitable for use between an amplification chain. Additionally, the differential equalizer is suitable for use coupled before or after an amplification chain in a transmitter or a receiver. The device comprises a differential equalizer for equalizing an input signal. The differential equalizer can be packaged into an integrated circuit for greater performance figures.

Abstract: The present invention is directed towards an optical receiver including an open loop automatic gain control (AGC) circuit. Optical signals received by the optical receiver are converted to electrical signals via a photodiode. The electrical signals are subsequently amplified through an input and an output amplifier stage. The amplified signal is then converted to RF signals and provided to an output port for further transmission. Concurrently, the AGC circuit senses the input optical power level at the input photodiode. The input optical power level is compared with a reference voltage, thereby providing a difference voltage. The difference voltage is applied to input and output amplifier stages for correcting the electrical signals to ensure a constant output power level.

Abstract: The present invention is directed towards an optical receiver including a noise reduction technique that mitigates internally generated thermal noise and reduces input signal losses. The optical receiver includes a photodiode for providing an electrical signal in accordance with a received optical signal and an amplification circuit. Two identical amplifier circuits included in the amplification circuit are connected in DC bias series, thereby biasing the photodiode with their potential difference. Advantageously, the absence of a conventional photodiode bias circuit both reduces the input signal losses and limits the amount of thermal noise that is typically conventionally generated.

Abstract: An amplifier circuit (400) includes an input port (402) for receiving a signal and a first balun (404) for splitting the signal into first and second signals. First and second amplifiers (406, 408) are coupled to outputs of the first balun (404) for respectively amplifying the outputs of the first balun (404) to generate first and second amplified signals. Second and third baluns (410, 412) are coupled, respectively, to outputs of the first and second amplifiers (406, 408) for splitting, respectively, each of the first and second amplified signals into in-phase and out-of-phase components.

Abstract: A protection circuit prevents a surge applied to one end of a signal line from being applied to a circuit connected to another end of the signal line. The protection circuit includes a first diode having an anode coupled to the signal line and a first capacitor having a first electrode coupled to a cathode of the first diode and a second electrode coupled to a first potential. A second capacitor has a first electrode coupled to the signal line and a second diode has a cathode coupled to a second electrode of said second capacitor and an anode coupled to the first potential. A first inductor is coupled between the cathode of the first diode and the cathode of the second diode. A power supply terminal is applied with a power supply potential and is coupled to one end of the first inductor.