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Potential large-scale landslides and earth-rock flow potential streams are located in remote mountainous areas, most of which overlap with aboriginal tribes. Since the Morakot typhoon disaster, the government has invested many resources in the potential soil and sand disasters. However, the number of such potential areas is too large to fully cover and monitor. After the Wulai District of New Taipei City, Taiwan, was severely damaged by the Sudil typhoon disaster in 2015, many significant landslides happened, and the Central Geological Survey, Taiwan, announced a total of 17 potential large-scale landslides. The area of potentially large-scale landslides in Xiluoan is the largest, about 6.5 km2, and covers the central residential area of the Wulai tribe. MT-InSAR (Multi-temporal Interferometric Synthetic Aperture Radar) is a powerful remote sensing technique for ground movement detection. The most popular method is the Persistent Scatterer Interferometry (PS-InSAR) in early 2000. The concept of PS-InSAR is to look for steady, point-like scatterers whose phases are consistent across entire time series SAR data. However, for those scatters are considered temporary targets or late-appearing persistent targets during an entire period; they are often ignored and not estimated. In order to overcome such limitation, an amplitude On-Off model, which uses a rectangular function to estimate temporary targets, was applied to the amplitude time series. Then, we used the On-Off model result as a weight in the InSAR time series processing frames. Two rectangular corner reflectors (CRs) were placed in the Wulai sites, potentially large landslide areas. 83 Sentinel-1 SLC ascending images acquired from Jan 2020 to Dec 2022 were used to estimate ground movement. It is evident that with the weight based on the amplitude on-off model, the late-appearing persistent targets are successfully identified. For example, the two CR locations can be readily found, and the velocity of the movement can be estimated. The amplitude of the pixel at the CR locations becomes significantly strong and stable after the date of setting up the CR targets. One CR covers a period of 20 images; the other covers a period of 31 images. The movement of one CR reveals an ongoing sliding trend. Such estimation is consistent with those typical PS targets located at the same slope sliding area.

A radar system requires a number of high-power components operating in a narrow and convection-free environment. This study aims to develop an integrated heat dissipation system that is suitable for the high-power electronic equipment of radar systems. The proposed heat dissipation mechanism integrates a fluid circulation-type cold plate with a quad transmit receive module. The finite element method in the COMSOL fluid–solid coupling heat transfer analysis software was used to analyze the heat dissipation performance of the cold plate in the proposed mechanism. The Taguchi method was adopted to optimize the cold plate design. The simulation and experimental results show that the proposed mechanism can control the temperature equalization and temperature of the system within the specified requirements. The practicality of the proposed mechanism was verified. The findings can serve as a reference for the design of high-power electronic equipment in a heat dissipation system.

In this work, a 12nm CMOS 2/3/4/5G multi-RAT (Radio Access Technology) XCVR is presented, capable of supporting up to 6 inter-band CA DL with flexible 4x4 MIMO port selection and 2 inter-band CA UL with coherent 2x2 MIMO. In NR 200MHz 4x4 MIMO 256QAM mode a throughput up to 5Gbps can be achieved. This work is housed in 2-layer Flip-Chip Chip-Scale Package (FCCSP).

With the explosion of online streaming, artificial intelligence and mobile computing, higher wireless data-rates are required, which in 5G NR are achieved by adopting massive MIMO and Carrier Aggregation (CA) with a wide channel bandwidth (BW) up to 200MHz. Together with the requirement for LTE+NR Dual Connectivity (EN-DC), the transceiver (XCVR) and RF front-end complexity increases dramatically requiring new techniques to maintain a small and cost-effective RF implementation. In this work, a 12nm CMOS 2/3/4/5G multi-RAT (Radio Access Technology) XCVR is presented, capable of supporting up to 6 inter-band CA DL with flexible 4×4 MIMO port selection and 2 inter-band CA UL with coherent 2×2 MIMO. In NR 200MHz 4×4 MIMO 256-QAM mode a throughput up to 5Gb/s can be achieved.

5G New Radio (NR) technology provides much higher data rate and system capacity compared to 4G LTE. This is achieved, among other techniques, by increasing the maximum channel bandwidth per component carrier (CC) from 20MHz in LTE to 100 MHz in NR and by introducing new frequency bands in the range of 3.3 to 5GHz [1]. A 4G/5G multimode multiband cellular transceiver must support this wide bandwidth and wide tuning range while maintaining excellent EVM for high-order modulation and high linearity and low noise for challenging LTE scenarios.

The extraction of land cover information from remote sensing data is a complex process. Spectral information has been widely utilized in classifying remote sensing images. However, shadows limit the use of multispectral images because they result in loss of spectral radiometric information. In addition, true reflectance may be underestimated in shaded areas. In land cover classification, shaded areas are often left unclassified or simply assigned as a shadow class. Vegetation indices from remote sensing measurement are radiation-based measurements computed through spectral combination. They indicate vegetation properties and play an important role in remote sensing of forests. Airborne light detection and ranging (LiDAR) technology is an active remote sensing technique that produces a true orthophoto at a single wavelength. This study investigated three types of geometric lidar features where NDVI values fail to represent meaningful forest information. The three features include echo width, normalized eigenvalue, and standard deviation of the unit weight observation of the plane adjustment, and they can be derived from waveform data and discrete point clouds. Various feature combinations were carried out to evaluate the compensation of the three lidar features to vegetation detection in shaded areas. Echo width was found to outperform the other two features. Furthermore, surface characteristics estimated by echo width were similar to that by normalized eigenvalues. Compared to the combination of only NDVI and mean height difference, those including one of the three features had a positive effect on the detection of vegetation class.

Airborne light detection and ranging (LiDAR) technology is an active remote sensing technique that produces a true orthophoto at a single wavelength. LiDAR is not as dependent on the weather as optical sensors, and LiDAR features have been widely applied for characterizing land cover classes of interest. Instead of using point-based features for classification, object-based LiDAR features were employed in this study. In addition, instead of directly mining a data set with large numerical attributes, a preprocessing step, known as data discretization, was applied before data mining. The results show that although original data are simplified, mining results are concise, more meaningful and easy-to-interpret. In this way, the accuracy of land cover classification can be further improved.

The RF front-end complexity in 4G multimode multiband cellular radios has increased dramatically, requiring integration of PAs, filters and switches in a single module to reduce the RF footprint. This paper presents a fully integrated multimode TDD transmit front-end module (TXM) supporting GSM/EDGE/TD-SCDMA/TD-LTE in multiple bands. The TXM is implemented with three die on a 2-layer laminate LGA module (Figs. 13.1.1 and 13.1.7). Two multimode multiband power amplifier paths (LB/HB) are implemented in a 0.153µm 1P6M CMOS process, followed by power combiners and harmonic filters in a 0.18µm 3M2V IPD die and finally an SP10T antenna switch in a 0.18µm 1P3M SOI process. The Si substrate of good thermal conductivity dissipates the heat generated by PA transistors to the laminated substrate, which solder mask opened and lots of ground vias are deployed underneath the die to effectively conduct the heat out of the package.

Medical records are important diagnostic tools designed to assist doctors in the management of their patients' health. Maintenance records are vital for on-site building managers in a comparable sense when planning the operational life cycle of the buildings housing health facilities. Unlike their medical counterparts though, these records are compromised by a lack of systematization and empirical verification. With a view to redressing these shortcomings, this paper introduces a knowledge extraction method that combines semantic indexing and clustering analysis, referred to as the Building Diagnosis Navigation System (BDN System).

A phased-array transmitter (TX) for multi-Gb/s non-line-of-sight links in the four frequency channels of the IEEE 802.15.3c standard (58.32 to 64.8 GHz) is fully integrated in a 0.12-μm SiGe BiCMOS process. It consists of an up-conversion core followed by a 1:16 power distribution tree, 16 phase-shifting front-ends, and a digital control unit. The TX core is a two-step sliding-IF up-conversion chain with frequency synthesizer that features 40 dB of gain programmability, I/Q balance and LO leakage correction, and a modulator for 802.15.3c common-mode signaling. The tradeoffs involved in the implementation of a 1:16 power distribution network are analyzed and a hybrid passive/active distribution tree architecture is introduced. Each of the 16 front-ends consists of a balanced passive phase shifter and a variable-gain, 3-stage PA that features oP1dB programmability through the bias control of the its final stage. All of the chip features are digitally controllable and individual memory arrays are integrated at each front-end to enable fast beam steering through a high-speed parallel interface. The IC occupies 44 mm and is fully characterized on wafer. The TX delivers 9 to 13.5 dBm oPidB per element at 60.48 GHz with a total power consumption of 3.8 to 6.2 W. Each element attains a phase-shift range >360° with an amplitude variation

This article summarizes the development of mature and highly integrated SiGe BiCMOS ICs for gigabit-per-second communications according to the requirements of the IEEE 802.15.3c and 802.11.ad-draft standards. A single-element transceiver chipset for point-to-point communications is described with emphasis on a feature-rich yet compact 60-GHz receiver. Next, a 16-element phased-array transceiver chipset for non-line-of-sight communications is described, with emphasis on a new power-efficient phased-array transmitter. Examples of gigabit-per-second line-of-sight and non-line-of-sight link experiments are provided, and system-level implementation trade-offs are discussed.

This paper presents a single-chip CMOS quad-band (850/900/1800/1900 MHz) RF transceiver for GSM/GPRS/EDGE applications which adopts a direct-conversion receiver, a direct-conversion transmitter and a fractional-N frequency synthesizer with a built-in DCXO. In the GSM mode, the transmitter delivers 4 dBm of output power with 1deg RMS phase error and the measured phase noise is -164.5 dBc/Hz at 20 MHz offset from a 914.8 MHz carrier. In the EDGE mode, the TX RMS EVM is 2.4% with a 0.5 dB gain step for the overall 36 dB dynamic range. The RX NF and IIP3 are 2.7 dB/-12 dBm for the low bands (850/900 MHz) and 3 dB/-11 dBm for the high bands (1800/1900 MHz). This transceiver is implemented in 0.13 mum CMOS technology and occupies 10.5 mm2. The device consumes 118 mA and 84 mA in TX and RX modes from 2.8 V, respectively and is housed in a 5 times 5 mm2 40-pin QFN package.

Background Our team previously demonstrated arterial stiffening and cardiac hypertrophy in type 2 diabetic rats at 8 but not 4 weeks after being administered streptozotocin (STZ) and nicotinamide (NA). The present study focused on investigating the effects of type 2 diabetes on cardiac autonomic nerve function in the STZ- and NA-treated animals, using modern spectral estimation technique. Design An autoregressive process was performed to each detrended signal of heart rate and systolic blood pressure measured in the 4- and 8-week STZ-NA rats with anaesthesia. The power of low-frequency and high-frequency oscillations was automatically quantified with each spectral peak by computing the residuals. The closed-loop baroreflex gain was estimated using the square root of the ratio between heart rate and systolic blood pressure powers in the low-frequency band. Results Compared with the age-matched controls, both the 4- and 8-week STZ-NA diabetic rats had significantly decreased low-frequency oscillations of heart rate but not systolic blood pressure variability, showing a decline in baroreflex gain (0·451 ± 0·060 and 0·484 ± 0·056 vs. 1·196 ± 0·064 ms mmHg−1, P

In 1991, a population-based epidemiologic traumatic brain injury (TBI) study was done in urban and rural areas of Taiwan; this was 5 years before the helmet use law was passed and 8 years before the drink driving law was passed. In order to evaluate the impact of three major determinants (time, geography, and legislation) on the epidemiology of TBI, we conducted a prospective study in 2001 and used the 1991 data to examine the differences in TBI distribution in urban and rural Taiwan a decade after these laws were passed. In 2001, 5754 TBI cases were collected from the urban area of Taipei City, and 1474 TBI cases were collected from the rural area of Hualien County. The TBI incidence rate in Taipei City in 2001 was estimated to be 218/100,000 population (285/100,000 for males and 152/100,000 for females). When compared to the 1991 data, the incidence rate in 2001 had increased by 20%. The TBI incidence rate in Hualien County in 2001 was estimated to be 417/100,000 population (516/100,000 for males and 306/100,000 for females); this was a 37% increase over the 1991 data. Our study found that the distribution of causes and age distribution had shifted significantly over the 10-year period. In 2001, the age group with the highest incidence was 20-29 years, while in 1991 it had been the over 70 years age group. While traffic-related TBI had decreased, falls and assaults had increased in 2001. We also found that legislation, such as the helmet law, affects TBI distribution by decreasing the traffic-related TBI rate, decreasing the admission severity of TBI, and reducing TBI-related mortality. Finally, geography plays a crucial role in the outcome of TBI; over the 10 year period, Taipei had an increase in moderately severe outcomes, while Hualien had an increase in more severe outcomes. Comparative studies of TBI in urban and rural areas have shown that time, legislation, and geography are crucial determinants of TBI epidemiology. Although time and legal interventions seem to have more of an impact, geography does affect TBI outcomes.

The use of multisource data in remote sensing image classification has become increasingly popular. Although additional features incorporated could improve classification accuracy, the amount of relevant information may induce interclass confusion. Feature selection plays an important role in image analysis process. This study investigates feature space optimization in the use of multispectral UltraCAM xp imagery and full waveform Riegl LMS 680i lidar data. Meaningful features are based on similar spectral or spatial properties.

A downconversion double-balanced oscillator mixer using 0.18-mum CMOS technology is proposed in this paper. This oscillator mixer consists of an individual mixer stacked on a voltage-controlled oscillator (VCO). The stacked structure allows entire mixer current to be reused by the VCO cross-coupled pair to reduce the total current consumption of the individual VCO and mixer. Using individual supply voltages and eliminating the tail current source, the stacked topology requires 1.0-V low supply voltage. The oscillator mixer achieves a voltage conversion gain of 10.9 dB at 4.2-GHz RF frequency. The oscillator mixer exhibits a tuning range of 11.5% and a single-sideband noise figure of 14.5 dB. The dc power consumption is 0.2 mW for the mixer and 2.94 mW for the VCO. This oscillator mixer requires a lower supply voltage and achieves a higher operating frequency among recently reported Si-based self-oscillating mixers and mixer oscillators. The mixer in this oscillator mixer also achieves a low power consumption compared with recently reported low-power mixers

The design and performance of two new miniature 360/spl deg/ continuous-phase-control monolithic microwave integrated circuits (MMICs) using the vector sum method are presented. Both are implemented using commercial 0.18-/spl mu/m CMOS process. The first phase shifter demonstrates all continuous phase and an insertion loss of 8 dB with a 37-dB dynamic range from 15 to 20 GHz. The chip size is 0.95 mm /spl times/ 0.76 mm. The second phase shifter can achieve all continuous phase and an insertion loss of 16.2 dB with a 38.8-dB dynamic range at the same frequency range. The chip size is 0.71 mm /spl times/ 0.82 mm. To the best of the authors' knowledge, these circuits are the first demonstration of microwave CMOS phase shifters using the vector sum method with the smallest chip size for all MMIC phase shifters with 360/spl deg/ phase-control range above 5 GHz reported to date.

This paper presents a 55nm 4-in-1 (11b/g/n, BT, FM, and GPS) radio assembled side-by-side with a 3-metal layer integrated-passive-device (IPD) chip in a QFN40 package. One 2.4GHz transceiver is area-efficiently shared between WiFi and Bluetooth systems. Including a 3dB IPD insertion loss, at chip output (antenna port) the saturated output power of the 11bgn integrated PA is 25dBm; the receiver noise figure is 6dB and 7dB in WiFi and BT modes, respectively. The shared synthesizer locks to within 4ppm target frequency during WiFi/BT channel switching in less than 23 usec. Tracking sensitivity of the GPS receiver and the sensitivity of the FM receiver (including IPD loss) are -162dBm and 2.7dBuVrms, respectively. The IPD chip contains a 2.4GHz WiFi/BT balanced tri-section filter and matching network; a 2.4GHz/1.6GHz diplexer; and a GPS 5th order elliptical filter and its matching network. The radio and IPD die sizes are 3.4mm 2 and 3.1mm 2 , respectively.

The growing demand for high-speed wireless communication has driven the evolution of cellular phone networks. New-generation cellular standards use wider channel bandwidth and more sophisticated modulation to obtain higher data-rates. Due to various cellular standards, chip providers are required to offer highly integrated solutions that support 2G, 3G, and even 4G in one chip. This paper presents a receiver supporting 2G quad bands and 3G TD-SCDMA dual bands. Figure 20.7.1 shows the 2G/3G receiver, whose front-end current-mode outputs are combined at baseband CR filter and biquad PGA, which are shared between all bands. A dynamic gain-bandwidth-product-extension circuit technique is used to remove a transimpedance amplifier to save die area and current.

With the rapid development of remote sensing, multiple techniques are now capable of producing digital elevation models (DEMs), such as photogrammetry, Light Detection and Ranging (LiDAR), and interferometric synthetic aperture radar (InSAR). Satellite-derived InSAR DEMs are particularly attractive due to their advantages of large spatial extents, cost-effectiveness, and less dependence on the weather. However, several complex factors may limit the quality of derived DEMs, e.g., the inherited errors may be nonlinear and spatially variable over an entire InSAR pair scene. We propose a segmentation-based coregistration approach for generating accurate InSAR DEMs over large areas. Two matching algorithms, including least squares matching and iterative closest point, are integrated in this approach. Three Advanced Land Observing Satellite Phased Array type L-band Synthetic Aperture Radar (ALOS PALSAR) InSAR DEMs are evaluated, and their root mean square errors (RMSEs) improved from 17.87 to 9.98 m, 51.94 to 15.80 m, and 27.12 to 12.26 m. Compared to applying a single global matching strategy, the segmentation-based strategy further improved the RMSEs of the three DEMs by 3.27, 13.01, and 9.70 m, respectively. The results clearly demonstrate that the segmentation-based coregistration approach is capable of improving the geodetic quality of InSAR DEMs.

A DC-11.5 GHz low-power amplifier is developed in commercial 0.13 mum, CMOS technology. This amplifier design is based on a three-stage shunt-feedback inverter-configuration with splitting load inductive peaking technique. The peaking inductor is placed at the gate of the nMOS to compensate gain roll-off of the inverter stage and extend its operating bandwidth. This amplifier achieves a gain flatness of 13.21 dB from dc to 11.5 GHz with I/O return losses better than 17 dB at a power consumption of 9.1 mW. The measured noise figure is less than 5.6 dB between 1-11 GHz. The output P1 dB is 8 dBm and input third-order intercept point is 10 dBm. The total chip size is 0.34 mm2 including all testing pads, with a core area of only 0.08 mm2.

A low-voltage and variable-gain distributed amplifier is presented in this letter. This microwave monolithic integrated circuit amplifier achieves 12-dB gain with a 3-dB frequency band of 1.6-12.1GHz and 6.5-dB noise figure under the bias condition of 0.8-V supply voltage and 6.4-mW total dc power consumption. The gain-control range is from -18dB to +20dB. Resistive metal-oxide-semiconductor field-effect transistors are used as termination resistors to compensate the mismatch due to different bias conditions. From 3.1 to 10.6GHz, the maximum gain ripple of this amplifier is only /spl plusmn/1dB for the gain level between -4 and 20dB.

A 24-GHz low-noise amplifier (LNA) was designed and fabricated in a standard 0.18-/spl mu/m CMOS technology. The LNA chip achieves a peak gain of 13.1 dB at 24 GHz and a minimum noise figure of 3.9 dB at 24.3 GHz. The supply voltage and supply current are 1 V and 14 mA, respectively. To the author's knowledge, this LNA demonstrates the lowest noise figure among the reported LNAs in standard CMOS processes above 20 GHz.

A low noise 5-GHz differential Colpitts CMOS voltage-controlled oscillator (VCO) is proposed in this letter. The Colpitts VCO core adopts only PMOS in a 0.18-/spl mu/m CMOS technology to achieve a better phase noise performance since PMOS has lower 1/f noise than NMOS. The VCO operates from 4.61 to 5 GHz with 8.3% tuning range. The measured phase noise at 1-MHz offset is -120.42 dBc/Hz at 5 GHz and -120.99 dBc/Hz at 4.61 GHz. The power consumption of the VCO core is only 3 mW. To the authors' knowledge, this differential Colpitts CMOS VCO achieves the best figure of merit (FOM) of 189.6 dB at 5-GHz band.

An LED panel lamp is presented for general indoor illumination. This lamp consists of arrayed LED light sources with each LED united with an evening lens so that the Lambertian distribution of LED light is altered, and the illuminance on a target plane can be uniform. The computer simulation result shows that the illuminance uniformity is 0.737, and the maximum illuminance is 140 lx on a detecting screen at 1.5 m away.

A 25-GHz complementary metal oxide semiconductor (CMOS) cascaded single-stage distributed amplifier (CSSDA) using standard 0.18-/spl mu/m CMOS technology is presented in this letter. It demonstrates the highest gain-bandwidth product (GBP) with smallest chip area reported for a fully-integrated CMOS wideband amplifier using a standard Si-based integrated circuit process. The chip size including testing pads is only 0.36mm/sup 2/, and the ratio of GBP to chip size achieves 552GHz/mm/sup 2/. This circuit is the first CSSDA realized in CMOS technology, and represents state-of-the-art performances.

An ultra-wideband mixer using standard complementary metal oxide semiconductor (CMOS) technology was first proposed in this paper. This broadband mixer achieves measured conversion gain of 11 /spl plusmn/ 1.5 dB with a bandwidth of 0.3 to 25 GHz. The mixer was fabricated in a commercial 0.18-/spl mu/m CMOS technology and demonstrated the highest frequency and bandwidth of operation. It also presented better gain-bandwidth-product performance compared with that of GaAs-based HBT technologies. The chip area is 0.8 /spl times/ 1 mm/sup 2/.

A 0.12-µm SiGe phased-array Rx IC for beam-steered wireless communication in the 60-GHz band is described. It has 16 RF phase-shifting front-ends with 11° digital phase resolution and hybrid passive-active RF signal combining. It achieves 7.4–7.9 dB NF (not including 12-dB array gain) over the 4 IEEE channels. The IC has a double-conversion superheterodyne Rx core with a maximum of 72 dB of power gain in 1-dB steps, and the on-chip synthesizer achieves ≪ −90 dBc/Hz Rx phase noise at 1MHz offset. The IC draws 1.8 W at 2.7 V with a die area of 38 mm2. It has been packaged with 16 antennas in a 288-pin organic BGA and phased-array beamsteering has been demonstrated, along with 5+ Gb/s wireless links using 16-QAM OFDM.

Integrated 60-GHz active and passive phase shifters for RF-path phase-shifting phased array transceivers are demonstrated in this paper. The reflection-type passive phase shifter achieves ≫180° phase variation across the 57GHz–64GHz band with insertion loss varying from 4.2dB–7.5dB at 60GHz. The active phase shifter employs vector-interpolation architecture and achieves 360° phase variation, −2dB gain, 12GHz 3dB bandwidth and 16.5dB noise figure at 60GHz. Measurements over process and temperature are also discussed and comparisons are drawn between active and passive phase shifting approach for 60GHz phased arrays.

A four-stage 60 GHz low-noise amplifier is implemented in 65 nm CMOS with nMOS ft of 210 GHz. The LNA incorporates a reflection-type attenuator to provide variable gain with improved linearity in low-gain mode and a tunable notch filter for image rejection. The LNA, which consists of two common-source stages followed by two cascode stages, consumes 30.8 mW and achieves 5.9 dB NF and 15 dB gain at 60 GHz. The variable attenuator provides 10 dB of gain variation with the input-referred 1 dB compression point of the LNA being -15.1 dBm in high gain mode and -6 dBm in the low-gain mode. Each tunable notch filter stage provides an additional 8 dB attenuation of 37 GHz image signals, with the four-stage LNA achieving more than 35 dB image-rejection.

This paper presents an integrated 26-MHz digitally-controlled crystal oscillator (DCXO) with temperature compensation function for multi-standard cellular applications, that achieves a phase noise of -154 and -159 dBc/Hz at 10 kHz and 100 kHz offset, respectively. The frequency instability over temperature is compensated by built-in temperature sensor and compensating capacitor. The frequency instability from -10 to 55 degC is about +/- 1 ppm. The AFC frequency tuning is done by a digitally-controlled metal-oxide-metal capacitor array that is 13-bit thermometer decoded. The DCXO is implemented in a 0.13-mum CMOS technology.

Subnatural linewidth in an optical transition in Cs was obtained by the suppression and recovery of the trapping of atoms. Cold Cs atoms in a magneto-optical trap (MOT) were irradiated using a weak probe laser to suppress MOT loading. When a counterpropagating coupling laser was directed to be resonant with the upper transition, the probe laser was induced to transmit and the MOT loading was recovered. This work investigates quantitatively this behavior by applying simulated electromagnetically induced transparency, taking into account the linewidth of the lasers as a decoherence source.

We present a freeform lens for application to LED uniform illumination. This lens, which is designed with a method of simple source-target luminous intensity mapping, can produce irradiance uniformity of greater than 0.8 and optical efficiency above 90% with an arbitrary half-beam angle greater than 45 deg. Typically, as compared with a conventional source-target energy mapping method, this design method can achieve better optical performance of lenses for general LED lighting. When a non-Lambertian-type light source is employed, for example, the chip on board LED, the use of the method can result in a compact LED lens without losing the optical performances of high irradiance uniformity and high optical efficiency as yielded by lenses for Lambertian-type LED light sources.

This paper proposes a quadrature voltage-controlled oscillator (QVCO) using 0.18-mum 1P6M standard CMOS process. The QVCO is realized by combining two differential oscillators via the bulk terminals. Using this approach, we can reduce the power dissipation and remove the noise from the additional coupling transistors compared with conventional QVCOs. To improve the phase noise, the oscillator is composed of Colpitts topology for lower phase noise than its cross-coupled counterpart. Moreover, the Colpitts oscillator adopts only PMOS to achieve a better phase noise performance because PMOS has less 1/f noise than NMOS. The VCO operates from 4.9 to 5.5 GHz with more than 11% tuning range. The measured phase noise at 600-kHz offset is -117 dBc/Hz at 5.2 GHz. The QVCO dissipates 10.8 mW at 1.8 V and achieves a good FOM of 185 dB.

A UWB low-power and low-noise amplifier is proposed. The UWB LNA achieves better than 14.5-dB gain with 10.8-mW power consumption. The measured minimum noise figure is 3.1 dB and lower than 5.4 dB in the desired band. This MMIC is implemented in a commercial 0.35-/spl mu/m SiGe BiCMOS technology and occupies total chip size of only 0.74 mm/sup 2/ including all testing pads.

This paper reviews our recent research effort on low-power low-noise amplifier for ultra-wideband applications. Two modified distributed amplifiers and one LNA using inductive-peaking technique for low-power UWB applications were developed. The two modified distributed amplifiers, consuming 5.4- and 6.4-mW dc power, have 10- and 12-dB small-signal gain, respectively. The NF is lower than 6.5 dB from 3.1 to 10.6 GHz. The inductive peaking LNA provides a gain of better than 14.5 dB and a NF of lower than 5.4 dB under 10.8-mW power consumption

A wide tuning range and low noise CMOS quadrature voltage-controlled oscillator (QVCO) using 0.18-mum 1P6M standard CMOS process is proposed in this paper. The VCO is realized employing switchable capacitors, so as to work in dual band and increase operation frequency. Moreover, the dual band operation could decrease the tuning sensitivity in each band and hence lower the phase noise. The VCO operates from 5.14 to 6.3 GHz with more than 20% tuning range. The measured phase noise at 1-MHz offset is -120.2 dBc/Hz at 5.5 GHz with VCO cores drawing total current of 8 mA at 1.8 V supply and the output power is about 1.5 dBm

A differential transimpedance amplifier combined with a positive feedback compensation circuit tolerates 1.5pF parasitic capacitance from ESD protection in 0.35 /spl mu/m SiGe BiCMOS. A 2.5Gb/s receiver demonstrates 15k/spl Omega/ transimpedance gain and DR from -3 to -23.5dBm while consuming 21mW from a 3V supply.

An offset-compensation method uses a peak detector and multiple tap feedback to achieve 1000/spl times/ improvement in settling time compared to prior art. Measurement results for a 3.125 Gbit/s limit amplifier with 42dB gain implemented in a 0.18 /spl mu/m CMOS process are presented.