Some Problems of 2D Morphological and Median Filters

In this paper we mainly discussed some problems of 2D morpnological and median filters .The differences between 1D and 2D morphological and median filters arc also described. It can be seen that many propcrties of ID finers arc invalid for 2D filters. Som cxamples and cxpcriments are gived to show these problems.

Tight upper bound on the quantum value of Svetlichny operators under local filtering and hidden genuine nonlocality

Nonlocal quantum correlations among the quantum subsystems play essential roles in quantum science.The violation of the Svetlichny inequality provides sufficient conditions of genuine tripartite nonlocality.We provide tight upper bounds on the maximal quantum value of the Svetlichny operators under local filtering operations,and present a qualitative analytical analysis on the hidden genuine nonlocality for three-qubit systems.We investigate in detail two classes of three-qubit states whose hidden genuine nonlocalities can be revealed by local filtering.

Size Reduction of Tunable Micromachined Filters for High Speed Operations

The size reduction of tunable micromachined filters is carried out for high-speed wavelength tuning. We fabricated micromachined filters having a miniature structure with an air gap of 300 run and a short cantilever of 45 urn, exhibiting fast response of below 3 us.

CMOS analog baseband circuitry for an IEEE 802.11 b/g/n WLAN transceiver

An analog baseband circuit for a direct conversion wireless local area network（WLAN） transceiver in a standard 0.13-μm CMOS occupying 1.26 mm^2 is presented.The circuit consists of active-RC receiver（RX） 4th order elliptic lowpass filters（LPFs）,transmitter（TX） 3rd order Chebyshev LPFs,RX programmable gain amplifiers （PGAs） with DC offset cancellation（DCOC） servo loops,and on-chip output buffers.The RX baseband gain can be programmed in the range of -11 to 49 dB in 2 dB steps with 50-30.2 nV/（Hz）^（1/2） input referred noise（IRN） and a 21 to -41 dBm in-band 3rd order interception point（IIP3）.The RX/TX LPF cutoff frequencies can be switched between 5 MHz,10 MHz,and 20 MHz to fulfill the multimode 802.11b/g/n requirements.The TX baseband gain of the I/Q paths are tuned separately from -1.6 to 0.9 dB in 0.1 dB steps to calibrate TX 1/Q gain mismatches.By using an identical integrator based elliptic filter synthesis method together with global compensation applied to the LPF capacitor array,the power consumption of the RX LPF is considerably reduced and the proposed chip draws 26.8 mA/8 mA by the RX/TX baseband paths from a 1.2 V supply.

A low-noise widely tunable Gm-C filter with frequency calibration

A fourth-order Gm-C Chebyshev low-pass filter is presented as channel selection filter for reconfigurable multi-mode wireless receivers. Low-noise technologies are proposed in optimizing the noise characteristics of both the Gm cells and the filter topology. A frequency tuning strategy is used by tuning both the transconductance of the Gm cells and the capacitance of the capacitor banks. To achieve accurate cut-off frequencies, an on-chip calibration circuit is presented to compensate for the frequency inaccuracy introduced by process variation. The filter is fabricated in a 0.13 m CMOS process. It exhibits a wide programmable bandwidth from 322.5 k Hz to20 MHz. Measured results show that the filter has low input referred noise of 5.9 n V/（Hz）^（1/2） and high out-of-band IIP3 of 16.2 d Bm. It consumes 4.2 and 9.5 m W from a 1 V power supply at its lowest and highest cut-off frequencies respectively.