Keng-Chih Lin

Bio: Keng-Chih Lin is an academic researcher from National Taiwan University. The author has contributed to research in topics: Microstrip antenna & Antenna tuner. The author has an hindex of 4, co-authored 8 publications receiving 193 citations.

A 24-GHz 3.9-dB NF low-noise amplifier using 0.18 /spl mu/m CMOS technology

Abstract: 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.

Simple Printed Multiband Antenna With Novel Parasitic-Element Design for Multistandard Mobile Phone Applications

Abstract: A simple printed multiband antenna with parasitic-element design for multi-standard handheld terminals in mobile communications is presented. The proposed antenna performs three resonance modes covering six bands of wireless standards, including GSM, GPS, DCS, PCS, UMTS, and LTE 2300/2500. In geometry, the antenna simply consists of two metal stubs. One is an L-shaped driven stub working as a feeder and an embedded transmission line. The other is a U-shaped parasitic stub working as a radiator. With fully printed and simple configuration, the proposed antenna design is cost effective in manufacturing and easy to optimize for different frequency bands. Parametric studies and the design rule are included. The antenna occupies an area of 18 × 37 mm2 on top of a system board. This communication covers the details of the antenna design, working principle, and the performances of simulation and measurement.

A Simple Printed Compensated Balun for Enhanced Ultra-Wideband Performances

Abstract: This letter presents a printed compensated balun of simple structure for enhanced ultra-wideband performances. The presented design stems from the generic compensated type of Marchand balun with an optimization on selected parameters for the bandwidth enhancement. A simple planar structure based on a 3-metal-layered PCB is proposed to realize the optimal design of the circuit scheme. The proposed balun design was implemented on a standard FR4 PCB and successfully verified with consistent simulation and measurement results. The presented balun achieves ultra wideband performances with a return loss better than 10 dB from 0.45 GHz to 6.85 GHz, a bandwidth ratio of 15:1. Over the entire bandwidth, the magnitude and phase imbalances are within 0.5 dB and 10 °, respectively. To the best of our knowledge, this work performs the largest bandwidth among the printed or planar baluns reported in the literature to date.

A planar multiband antenna with parasitic-element design for multistandard mobile terminals

Abstract: In conclusion, a novel planar PCB multiband antenna with parasitic element is proposed in this paper. Using only two simple radiating elements, the antenna operates with three separate resonant modes, covering six popular communication bands. The antenna area only occupies a small physical space (18 × 37 × 0.6 mm3). This simple planar PCB structure makes the antenna fabrication very cost effective. The proposed antenna performs a stable gain level and omni-directional patterns in the desired bands.

Wideband circularly-polarized aperture antenna arrays utilizing UWB directional coupler

Abstract: A novel wideband CP antenna array using the UWB directional coupler and sequential rotation technique is presented. The proposed antenna array is composed of two rectangular aperture antennas and a directional coupler as the sequential feeding scheme. The coupler was successfully designed and implemented, where two output port signals of 90°±10° phase difference and 3-dB magnitude imbalance were achieved over a ultra wide band 1.5 – 5.3 GHz. The resultant array showed a 10-dB return loss bandwidth in the 1.7–5.5 GHz band (103%) and a 3-dB axial ratio (AR) bandwidth in the 2.2–5.3 GHz band (82%).

Millimeter-Wave Low Power and Miniature CMOS Multicascode Low-Noise Amplifiers with Noise Reduction Topology

Abstract: In this paper, the design and analysis of CMOS multicascode configuration with noise reduction topology are proposed. Two low power and miniature low-noise amplifiers (LNAs) were designed and fabricated for demonstration. One with cascode device was designed at V -band in 65-nm process, and the other with triple-cascode structure was fabricated at Q -band in 0.13-? m technology. To minimize the noise figure and maximize the small-signal gain, inductors are designed and placed between transistors of the cascode and triple-cascode configurations. Based on this approach, the Q-band LNA has a gain of 14.3 dB and a noise figure of 3.8 dB at 38 GHz, with a power consumption of 28.8 mW. The V-band LNA presents a gain of 14.4 dB and a noise figure of 4.5 dB at 54.5 GHz, with a power consumption of 10 mW. The chip size of the V- and Q-band LNAs are 0.55 × 0.45 mm2 and 0.42 × 0.6 mm2, including all the testing pads. Compared with the conventional cascode LNAs, the proposed cascode LNA shows better noise figure and lower power consumption whereas the triple-cascode LNA features higher gain performance.

Electronic device and method for operating the same

Abstract: An NFC-enabled electronic device and a method for operating the same are discussed. The method according to an embodiment includes performing, by the electronic device, tagging with a first external device to establish communication with the first external device; receiving, by the electronic device, at least one of device information and user information from the first external device through the communication; and transmitting, by the electronic device, a remote control signal to at least one second external device, based on the at least one of the device information and the user information.

A Dielectric Resonator-Loaded Minkowski Fractal-Shaped Slot Loop Heptaband Antenna

Abstract: A multiband fractal co-planar waveguide (CPW)-fed slot antenna loaded with a dielectric resonator conforming to multiple wireless standards is presented in this paper. The Minkowski fractal geometry is utilized to generate multiple frequency bands as well as to provide a miniaturized design compared to its Euclidean counterpart. The idea behind placing the dielectric load is to serve a dual purpose of enhancing the impedance bandwidth of the antenna at the upper frequency band as well as improving the overall gain of the antenna. The slot loop acts as a hybrid antenna performing the task of both an antenna as well as a feed mechanism for the dielectric slab to radiate. Design guidelines involving closed form formulae and equivalent model consisting of lumped resonators, distributed resonators and impedance transformers of the dielectric-loaded fractal slot antenna are provided to present an insight into the functioning of the antenna. The reflection coefficient parameters of the antenna yield a close match between the circuit model and those obtained from full wave simulator. The proposed antenna exhibits a heptaband performance with a maximum gain of 3.1 dBi.

A low-power up-conversion CMOS mixer for 22-29-GHz ultra-wideband applications

Abstract: A double-balanced, low-power, and low-voltage dual-gate up-conversion mixer working at K-band is designed and fabricated in the UMC 130-nm logic CMOS process. The mixer achieves a 3-dB conversion-gain bandwidth of 1.8 GHz at the input IF port and a 3-dB conversion-gain bandwidth of 10 GHz at the output RF port. The mixer achieves an output referred 1-dB compression point as high as -5.8 dBm and an output referred third-order intercept point as high as 5.8 dBm, while consuming 8.0 mW from a 1.2-V supply. This study demonstrates that the implementation of low-power mixers operating in the 22-29-GHz band for ultra-wideband automotive radar applications is possible in low-cost and low-voltage logic CMOS technology

Low-Profile Narrow-Frame Antenna for Seven-Band WWAN/LTE Smartphone Applications

Abstract: A small-size low-profile narrow-frame antenna for seven-band WWAN/LTE operations in the internal smartphone applications is proposed. The greatest highlight of this proposed antenna is that its narrow edge has a width of only 5 mm, which is very novel for smartphone applications. Meanwhile, the proposed narrow-frame antenna has a small size of 5 × 40 mm2 and a low profile of 3 mm above the circuit board, which makes it very promising for slim smartphone applications. The proposed antenna is capable of covering GSM850/900/DCS/PCS/UMTS 2100/LTE2300/2500 operating bands. Detailed design considerations of the proposed antenna are described, and both experimental and simulation results are also presented and discussed.