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.

A standard CMOS compatible monolithic photo-detector and trans-impedance amplifier

A 1GHz monolithic photo-detector (PD) and trans-impedance amplifier (TIA) is designed with the standard 0.35 mu m CMOS technique. The design of the photo-detector is analyzed and the CMOS trans-impedance amplifier is also analyzed in the paper. The integrating method is described too. The die photograph is also showed in the paper.

Harmonic mode-locked ytterbium-doped fibre ring laser

We demonstrate a harmonic mode-locked ytterbium-doped fibre ring laser, which consists of a polarization-sensitive isolator, two polarization controllers, two 976 nm laser diodes as the pump source and a two-segment ytterbium-doped fibre. Utilizing an additive pulse mode-locked technique based on nonlinear polarization evolution, the ytterbium-doped fibre laser can operate in mode-locked state by adjusting the position of polarization controllers. The cavity fundamental repetition rate is 23.78 MHz. We also observe the second- and third-harmonic mode locking in the normal dispersion region, and their repetition rates are 47.66 MHz and 71.56 MHz, respectively. Over-driving of the saturable absorber in the harmonic mode-locking pulse is analysed and discussed in detail.

Phase mismatching analysis of third harmonic generation in BBO crystal

对BBO晶体三次谐波转换过程中相位失配情况进行了研究。当BBO 晶体按Ⅰ类相位匹配(oo→e)进行三次谐波转换时，如果保持基频光正入射，当倍频光从两个相互独立的平面方向(晶体主截面及主截面的垂面)偏离预期方向时，相位失配将出现变化，并且在两个面内的偏离量对转换效率的影响程度不同。我们分别数值模拟了两个方向上的相位失配情况，并给出了谐波转换效率同入射角度偏差的关系。数值模拟结果表明，在主截面内的相位匹配容限角为0.2°，在主截面垂面内的相位匹配容限角为4.5°。同时，开展了实验研究，实验结果与数值模拟结果高度吻合，表明在主截面内的角度偏差对转换效率的影响更大。

Harmonic Millimeter Wave Generation and Frequency Up-Conversion Using Optical Injection Locking and Brillouin Selective Sideband Amplification

Harmonic millimeter wave (mm-wave) generation and frequency up-conversion are experimentally demonstrated using optical injection locking and Brillouin selective sideband amplification (BSSA) induced by stimulated Brillouin scattering in a 10-km single-mode fiber. By using this method, we successfully generate third-harmonic mm-wave at 27 GHz (f(LO) - 9 GHz) with single sideband (SSB) modulation and up-convert the 2GHz intermediate frequency signal into the mm-wave band with single mode modulation of the SSB modes. In addition, the mm-wave carrier obtains more than 23 dB power gain due to the BSSA. The transmission experiments show that the generated mm-wave and up-converted signals indicate strong immunity against the chromatic dispersion of the fibers.

Near-Infrared Femtosecond Laser for Studying the Strain in Si1-xGex Alloy Films via Second-Harmonic Generation

The second-harmonic generation (SHG) from Si1-xGex alloy films has been investigated by near-infrared femtosecond laser. Recognized by s-out polarized SHG intensity versus rotational angle of sample, the crystal symmetry of the fully strained Si0.83Ge0.17 alloy is found changed from the O-h to the C-2 point group due to the inhomogeneity of the strain. Calibrated by double crystal X-ray diffraction, the strain-induced chi((2)) is estimated at 5.7 x 10(-7) esu. According to the analysis on p-in/s-out SHG, the strain-relaxed Si0.10Ge0.90 alloy film is confirmed to be not fully relaxed, and the remaining strain is quantitatively determined to be around 0.1%.

An asymmetric MOSFET-C band-pass filter with on-chip charge pump auto-tuning

An asymmetric MOSFET-C band-pass filter(BPF)with on chip charge pump auto-tuning is presented.It is implemented in UMC (United Manufacturing Corporation)0.18μm CMOS process technology. The filter system with auto-tuning uses a master-slave technique for continuous tuning in which the charge pump OUtputs 2.663 V, much higher than the power supply voltage, to improve the linearity of the filter. The main filter with third order low-pass and second order high-pass properties is an asymmetric band-pass filter with bandwidth of 2.730-5.340 MHz. The in-band third order harmonic input intercept point(HP3) is 16.621 dBm,wim 50 Ω as the source impedance. The input referred noise iS about 47.455μVrms. The main filter dissipates 3.528 mW while the auto-tuning system dissipates 2.412 mW from a 1.8 V power supply. The filter with the auto-tuning system occupies 0.592 mm~2 and it can be utilized in GPS (global positioning system)and Bluetooth systems.