We demonstrate a monolithically integrated dual-quadrature coherent receiver with greater than 30 nm widely-tunable SG-DBR local oscillator, signal input SOAs, a 90° optical hybrid and four 10 GHz photodetectors. With 20 Gb/s NRZ-QPSK, we demonstrate a required OSNR of 10 dB for a BER of 10(-3) at four different wavelengths.

A high-frequency low-power sinusoidal quadrature oscillator is presented through the use of two 2-order low-pass current-mirror (CM)-based filters, a 1-order CM low-pass filter and a CM bilinear transfer function. The technique is relatively simple based on (i) inherent time constants of current mirrors, i.e. the internal capacitances and the transconductance of a diode-connected NMOS, (ii) a s...

This paper presents a 20 GHz push-push VCO realized by a 10 GHz super-harmonic coupled quadrature oscillator for a quadrature 60 GHz frequency synthesizer. The output nodes are peaked by a tunable second harmonic resonator. The proposed VCO is implemented in 65 nm CMOS process. It achieves a tuning range of 3.5 GHz from 16.1 GHz to 19.6 GHz with a phase noise of −106 dBc/Hz at 1 MHz offset. The...

A new concept for quadrature coupling of oscillators is introduced and demonstrated on a 5-GHz CMOS voltagecontrolled oscillator (VCO). It uses the second harmonic of the outputs to couple the oscillators. The technique provides quadrature over a wide tuning range without introducing any increase in phase noise or power consumption. The VCO is tunable between 4.57 and 5.21 GHz and has a phase n...

The novel current-tunable voltage-mode universal biquad filter and sinusoidal quadrature oscillator using only two current-controlled current differencing buffered amplifiers (CCCDBAs) and two capacitors without external passive resistors have been presented. The first proposed filter realizes all the five standard types of the biquadratic functions and provides independent electronic tuning of...

This work proposes a direct sequence spread spectrum transmitter with high transmission range and efficiency for audio signals. It is shown that by choosing high process gain for spread spectrum signal the data could reach a range of 55km in the 2.4GHz ISM band. By employing a light modulation scheme, we have a relaxed SNR requirement for having a low bit error rate (BER) which translates to re...