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In a radio frequency (RF) system, it is possible to use variable inductors for providing tunable or selective frequency range. Variable inductors can be implemented by the microelectromechanical system (MEMS) process or by using transistors as switches to change the routing of coils or coupling quantities. In this paper, we investigated the design method of a variable inductor by using MOS transistors to switch the main coil paths and the secondary coupled coils. We observed the effects of different metal layers, turn numbers, and layout arrangements for secondary-coupled coils and compared their characteristics on the inductances and quality factors. We implemented two chips in the 0.18 μm CMOS process technology for each kind of arrangement for verification. One inductor can achieve inductance values from about 300 pH to 550 pH, and the other is between 300 pH and 575 pH, corresponding to 59.3% and 62.5%, respectively, inductance variation range at 4 GHz frequency. Additionally, their fine step sizes of the switched inductances are from 0.5% to 6% for one design, and 1% to 12.5% for the other. We found that both designs achieved a large inductance tuning range and moderate inductance step sizes with a slight difference behavior on the inductance variation versus frequency.

In this paper, a three-stage common-source power amplifier (PA) fabricated in the TSMC 90-nm CMOS process technology for V-band applications is presented. The proposed PA adopts the transformer structure to split and combine power and to implement the matching network. The CMOS PA achieves a measured gain of 17.8 dB, and its saturated output power, P sat , is 13.8 dBm at the 10-dBm input power. The measured OP 1dB is 13.36 dBm and the peak power added efficiency (PAE) is 16.9%. The chip size of the proposed PA is 1.05 × 0.47 mm2, and the power dissipation is 139 mW under a 1.2-V supply voltage.

A fully integrated power amplifier (PA) which is implemented in the 90-nm CMOS process technology for V-band applications is presented in this paper. The proposed PA is composed of three-stage common-source configuration and adopts Marchand baluns for power dividing/combining in the third stage. The CMOS PA delivers a 9-dBm saturated output power (i.e. P sat ) and has a 7.3-dBm output 1-dB compression point (OP 1dB ) at 60 GHz. It performs a maximum power gain of 5.4 dB and a peak power-added efficiency (PAE) of 1.81%. The proposed PA draw a power consumption of 215 mW from the 1.2-V supply.

Colorless alicyclic polyimides (ALPIs) were synthesized from an alicyclic dianhydride, bicyclo[2.2.2]oct-7-ene-2,3,5,6-tetracarboxylic dianhydride (BCDA) and an aromatic diamine, 3,4'-oxydianiline (3,4'-ODA). For comparison, a series of crosslinkable ALPI membranes with different content of crosslinkable reagents were prepared. The crosslinkable PI reacts with the crosslinkers and forms covalent bond to create the crosslink structure between PI backbones by free radical reaction. Almost of the crosslinkable PIs exhibit excellent dimensional stability and higher transparency because of the crosslink structure and non-conjugate alicyclic chain. All of the crosslink ALPIs could be coated into flexible and tough films. They had a UV-Vis cut-off at 297 nm and a transmittance of higher than 80% in near ultraviolet region. These PIs show low coefficient of thermal expansion ranging from 57.36 to 47.53 ppm/°C, the glass transition temperature in the range of 336.2-333.0 °C, the decomposition temperature in the range of 433.7-440.0 °C. The crosslinkable ALPIs show excellent optical properties with the excited wavelength ranging from 340 to 328 nm and stronger emission intensity than linear PI, the haze lower than 0.7, the refractive index about 1.6 and the abbe numbers over 165.

A series of polyimide/vanadium pentoxide (PI/V2O5) hybrid film has been successfully fabricated through the in situ formation of V2O5 within a polymer matrix by sol–gel process. The polyamic acid (PAA) is prepared from 4,4 0 -diaminodiphenyl ether (ODA) and 3,3 0 ,4,4 0 -benzophenonetetracarboxylic anhydride (BTDA) in N-methylpyrrolidinone (NMP) solvent. Then different amounts of Bis-(2,4-pentanedionato) vanadium oxide are incorporated into polyamic acid (PAA) matrix, respectively and then thermally imidized to form PI/V2O5 hybrid membranes. The imidization temperature and time are optimized by FTIR measurements through the observation of V2O5 absorption peak. The influence of V2O5 content on the thermal stability, morphology and mechanical properties of PI/V2O5 hybrid films are studied.

Goal of proposed algorithm is to enhance images like the digital camera photos or, better. Some enhancement filters process too excessive that makes image look unnatural. The paper proposes an algorithm to represent obviously the detailed textures and sharpen the overall image based on perceptual approach. Then the sharpened images are merged by the edge information of original image. The experimental results show that the detailed textures can be easily observed. The whole image looks not only more sharp but also natural after applying our algorithm.

This paper proposes a z-domain technique to design a reconfigurable dual-band bandpass filter. An arbitrarily pre-defined bandpass filter is implemented by using parallel stubs. Switch circuits shunted with two-section stubs are employed to induce the narrow passbands on arbitrarily bandpass filters. The simulated results show that 3-dB bandwidths are 130 MHz and 70 MHz at the center frequencies of 1.55 GHz and 2.12 GHz, respectively.