A Complex BPF with On Chip Auto-tuning Architecture for Wireless Receivers

A 3(rd) order complex band-pass filter (BPF) with auto-tuning architecture is proposed in this paper. It is implemented in 0.18um standard CMOS technology. The complex filter is centered at 4.092MHz with bandwidth of 2.4MHz. The in-band 3(rd) order harmonic input intercept point (IIP3) is larger than 16.2dBm, with 50 Omega as the source impedance. The input referred noise is about 80uV(rms). The RC tuning is based on Binary Search Algorithm (BSA) with tuning accuracy of 3%. The chip area of the tuning system is 0.28 x 0.22 mm(2), less than 1/8 of that of the main-filter which is 0.92 x 0.59 mm(2). After tuning is completed, the tuning system will be turned off automatically to save power and to avoid interference. The complex filter consumes 2.6mA with a 1.8V power supply.

A Complex BPF with On Chip Auto-tuning Architecture for Low-IF Receivers

A 3(rd) order complex band-pass filter (BPF) with auto-tuning architecture is proposed in this paper. It is implemented in 0.18 mu m standard CMOS technology. The complex filter is centered at 4.092MHz with bandwidth of 2.4MHz. The in-band 3(rd) order harmonic input intercept point (IIP3) is larger than 19dBm, with 50 Omega as the source impedance. The input referred noise is about 80 mu V-rms. The RC tuning is based on Binary Search Algorithm (BSA) with tuning accuracy of 3%. The chip area of the tuning system is 0.28x0.22mm(2), less than 1/8 of that of the main-filter which is 0.92x0.59mm(2). After tuning is completed, the tuning system will be turned off automatically to save power and to avoid interference. The complex filter consumes 2.6mA with a 1.8V power supply.

Tuning of emission wavelength of InAs/GaAs quantum dots sandwiched by combination layers

We investigate about controlling of photoluminescence (PL) wavelengths of InAs/GaAs self-assembled quantum dots (QDs) sandwiched with combination strained-buffer layer (CSBL) and combination strained-reducing layer (CSRL). The emission peak position of QDs is red-shifted to 1.37 mu m. The density of the QDs is increased to 1.17x10(10) cm(-2). It is indicated that optical properties of QDs could be improved by optimizing of the buffer and covering layers for the QDs. These results may provide a new way to further developing GaAs-based 1.3 mu m light sources.

An ambient proof and wide tuning range LC VCO with automatic amplitude control for tuner applications

This paper represents a LC VCO with AAC (Auto Amplitude Control), in which PMOS FETs are used as active components, and the varactors are directly connected to ground to widen Kvco linear range. The AAC circuitry adds little noise to the VCO and provides it with robust performance over a wide temperature and carrier frequency range. The VCO is fabricated in 50-GHz 0.35-mu m SiGe BiCMOS process. The measurement results show that it has -127.27-dBc/Hz phase noise at 1-MHz offset and a linear gain of 32.4-MHz/V between 990-MHz and 1.14-GHz. The whole circuit draws 6.6-mA current from 5.0-V supply.

Period Continuous Tuning of an Efficient Mid-Infrared Optical Parametric Oscillator Based on a Fan-out Periodically Poled MgO-Doped Lithium Niobate

We report a period continuously tunable, efficient, mid-infrared optical parametric oscillator (OPO) based on a fan-out periodically poled MgO-doped congruent lithium niobate (PPMgLN). The OPO is pumped by a Nd:YAG laser and a maximum idler output average power of 1.65 W at 3.93 mu m is obtained with a pump average power of 10.5 W, corresponding to the conversion efficiency of about 16% from the pump to the idler. The output spectral properties of the OPO with the fan-out crystal are analyzed. The OPO is continuously tuned over 3.78-4.58 mu m (idler) when fan-out periods are changed from 27.0 to 29.4 mu m. Compared with temperature tuning, fan-out period continuous tuning has faster tuning rate and wider tuning range.

Tuning the Exciton Binding Energies in Single Self-Assembled InGaAs/GaAs Quantum Dots by Piezoelectric-Induced Biaxial Stress

We study the effect of an external biaxial stress on the light emission of single InGaAs/GaAs(001) quantum dots placed onto piezoelectric actuators. With increasing compression, the emission blueshifts and the binding energies of the positive trion (X+) and biexciton (XX) relative to the neutral exciton (X) show a monotonic increase. This phenomenon is mainly ascribed to changes in electron and hole localization and it provides a robust method to achieve color coincidence in the emission of X and XX, which is a prerequisite for the possible generation of entangled photon pairs via the recently proposed "time reordering'' scheme.

Wavelength multiplexing and tuning in nano-Ag/dielectric multilayers

Multicolored optical active planes have been fabricated with magnetron sputter method coupled with selective masking technique. The plane is multilayer structured with Ag nanoparticles and TiO2 thin layer as the building blocks. It was found that the formed multilayer can be readily wavelength multiplexed by simply overlapping several nano-Ag/TiO2 layered structures, each of which may have different surface plasmon resonance wavelength. Unlike high order multiple resonances of large particles each of the multiplexing wavelengths in such a system is separately tunable. Importantly, it reveals that modification of the TiO2 layer thickness generates a fine tuning of the resonance wavelength.

Nano-Ag on vanadium dioxide. II. Thermal tuning of surface plasmon resonance

Thermal tuning of the localized surface plasmon resonance (LSPR) of Ag nanoparticles on a thermochromic thin film of VO2 was studied experimentally. The tuning is strongly temperature dependent and thermally reversible. The LSPR wavelength lambda(SPR) shifts to the blue with increasing temperature from 30 to 80 degrees C, and shifts back to the red as temperature decreases. A smart tuning is achievable on condition that the temperature is controlled in a stepwise manner. The tunable wavelength range depends on the particle size or the mass thickness of the metal nanoparticle film. Further, the tunability was found to be enhanced significantly when a layer of TiO2 was introduced to overcoat the Ag nanoparticles, yielding a marked sensitivity factor Delta lambda(SPR)/Delta n, of as large as 480 nm per refractive index unit (n) at the semiconductor phase of VO2.

Wavelength multiplexing and tuning in nano-Ag/dielectric multilayers

Multicolored optical active planes have been fabricated with magnetron sputter method coupled with selective masking technique. The plane is multilayer structured with Ag nanoparticles and TiO2 thin layer as the building blocks. It was found that the formed multilayer can be readily wavelength multiplexed by simply overlapping several nano-Ag/TiO2 layered structures, each of which may have different surface plasmon resonance wavelength. Unlike high order multiple resonances of large particles each of the multiplexing wavelengths in such a system is separately tunable. Importantly, it reveals that modification of the TiO2 layer thickness generates a fine tuning of the resonance wavelength.

40-GHz wavelength tunable mode-locked SOA-based fiber laser with 40-nm tuning range

A 40-GHz wavelength tunable mode-locked fiber ring laser based oil cross-gain modulation in a semiconductor optical amplifier (SOA) is presented. Pulse trains with a pulse width of 10.5 ps at 40-GHz repetition frequency are obtained. The laser operates with almost 40-nm tuning range. The relationship between the key laser parameters and the output pulse characteristics is analyzed experimentally.