다중혈관 관상동맥 환자에서 y-문합을 이용하여 양쪽 내흉동맥만을 사용한 우회술의 조기 성적

In general, Micropower Impulse Radar (MIR) depends on Ultra-Wideband (UWB) transmission systems. UWB technology can supply innovative new systems and products that have an obvious value for radar and communications uses. Important applications include bridge-deck inspection systems, ground penetrating radar, mine detection, and precise distance resolution for such things as liquid level measurement. Most of these UWB inspection and measurement methods have some unique qualities, which need to be pursued. Therefore, in considering changes to Part 15 the FCC needs to take into account the unique features of UWB technology. MIR is applicable to two general types of UWB systems: radar systems and communications systems. Currently LLNL and its licensees are focusing on radar or radar type systems. LLNL is evaluating MIR for specialized communication systems. MIR is a relatively low power technology. Therefore, MIR systems seem to have a low potential for causing harmful interference to other users of the spectrum since the transmitted signal is spread over a wide bandwidth, which results in a relatively low spectral power density.

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Response to FCC 98-208 notice of inquiry in the matter of revision of part 15 of the commission's rules regarding ultra-wideband transmission systems

In this letter, a band-notched ultrawideband (UWB) antenna is presented and the notched-band characteristic is realized by a compact coplanar waveguide (CPW) resonant cell (CCRC). The antenna with a total size of 46 mm $,times,$30 mm operates in a band from 2.67 to over 12 GHz, and shows omnidirectional radiation patterns. Measurements indicate that the antenna presents a notched band from 5.10 to 5.94 GHz for $ VSWR ge 3:1$, which covers the wireless local area network (WLAN) band. The time-domain behaviors and the CCRC are discussed and the group delay is given experimentally. Also, parametric studies are performed numerically in the end.

A Band-Notched Ultrawideband Printed Monopole Antenna

In this letter, pseudo-interdigital stepped impedance resonators (PI-SIRs) are used to design the bandpass filter (BPF) with dual-band response. By tuning the impedance ratio (K) and physical length of SIRs, the BPF has good dual-passband performances at 2.4/5.2GHz and high isolation between the two passbands. It is shown that the dual-band BPF has a smaller area and lower insertion loss in comparison of previous works. Good agreement is shown between the full-wave electromagnetic simulation and the measurement

Compact and Low Loss Dual-Band Bandpass Filter Using Pseudo-Interdigital Stepped Impedance Resonators for WLANs

This study presents a novel microstrip diplexer with a joint T-shaped resonator. The T-shaped resonator has an extremely small frequency ratio using microstrip with practical line width. Additionally, the T-shaped resonator can be used as a frequency selective signal splitter, making it feasible to design a diplexer for a system with two extremely close bands. The diplexer using a joint T-shaped resonator does not require combining circuits and matching networks. A diplexer used in the UMTS-WCDMA system is designed and measured. The proposed diplexer has high isolation and wide stopband in addition to satisfying the passband requirement. A satisfactory agreement between the simulated results and the measured results validate the proposed configuration.

Microstrip Diplexer Design Using Common T-Shaped Resonator

A high performance hairpin line diplexer for the direct sequence ultra-wideband communication is designed and implemented. This microstrip diplexer is mainly composed of two hairpin line wideband bandpass filters and a tapped open stub. The design concept is proposed in detail and has been verified by the experimental results of the fabricated diplexer, including the two isolated wideband bandwidths of 3.1-5.0 GHz and 6.02-10 GHz, low insertion loss and high isolation. Experimental results also show a good agreement with the simulated results.

A Hairpin Line Diplexer for Direct Sequence Ultra-Wideband Wireless Communications

This letter presents a tri-band bandpass filter (BPF) with a wide stopband using asymmetric stub-loaded resonators (ASLR). A tri-band filter sample was fabricated by using two ASLRs with coupled I/O ports. By properly tuning the electrical length ratios of the ASLRs ( $\alpha$ and $\gamma$ ), three passbands can be designed at 1.4, 2.4, and 3.5 GHz. The harmonic responses are suppressed effectively by forming an uncoupled section at the end of the ASLRs, and the stopband region is formed from 3.7 to 7 GHz with a rejection level of 30 dB. The measured results of the fabricated tri-band BPF exhibit good agreement with simulated results.

A Tri-Band Bandpass Filter With Wide Stopband Using Asymmetric Stub-Loaded Resonators

In the design of high-speed and high frequency IC’s,the inﬂuence of the substrate on the circuit performance must beconsidered carefully. This work investigates the loss characteristic ofsilicon substrate with different resistivities and distinguishes theoreti-cally and experimentally the dielectric losses into the intrinsic loss ofsilicon (tan D ) and the extrinsic substrate leakage loss (tan L )caused by the ﬁnite conductivity of the substrate. The dielectric re-laxation (cut off) frequency as a function of silicon substrate resistiv-ity are calculated as considering the conditions of substrate noiseisolation and RF passive device design. © 2006 Wiley Periodicals, Inc.Microwave Opt Technol Lett 48: 1773–1776, 2006; Published online inWiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21786 Key words: conductivity; dielectric loss; intrinsic loss; extrinsic loss;tan L 1. INTRODUCTION There is a steady increase in the demand for high-density, low-cost, compact RF front ends, and microwave monolithic integratedcircuits (MMICs) [1] for wireless and portable communication.The integration of a large number of passive components includingthe individual passive devices of transmission lines, inductors,capacitors, or functional passive devices of ﬁlters and antennaswith low loss and minimal crosstalk is as important as the ad-vancement in active transistor technology [2]. However, the low-resistivity substrate used in standard CMOS processing for mostMMICs has limited the integration of high-quality passive com-ponents. There has been a large amount of research, both inindustry and in academia, to overcome the high attenuation of thepassive components on lossy silicon substrate to develop high-quality microwave circuits and modules [2–5]. High resistivitysilicon (HRS) has been proven as a solution for reducing thesubstrate leakage loss and suppressing substrate noise of the pas-sives, and HRS substrates can be realized by MeV proton implan-

Loss characteristics of silicon substrate with different resistivities

This letter presents a design of a compact ultra-wideband (UWB) bandpass filter (BPF), which can exhibit an UWB response from 3.1 to 9.9 GHz with low insertion loss (IL) of 0.8 dB and an extremely broad stopband region from 10.9 to 25.1 GHz with high rejection level of 20 dB. This UWB BPF is simply constructed by using only one single-stage parallel-coupled line and two rectangular stub resonators. In this design, the rectangular stub resonators provide an exciting mode to enhance the desired UWB response and also create tunable transmission zeros to extend a wide stopband by controlling the impedance ratio $(R)$ properly. The filter was fabricated and measured to verify the design concept.

Design of a Compact Ultra-Wideband Bandpass Filter With an Extremely Broad Stopband Region

In this paper, we presented the design of a high performance diplexer for applications of global positioning system (GPS) at 1.575GHz and wireless local area network (WLAN) at 2.4GHz, simultaneously. Two bandpass fllters (BPFs) using the modifled stepped-impedance resonators (SIRs) operated at 1.575GHz and 2.4GHz are the main blocks for the proposed diplexer. By discussing and analyzing the admittance of the even and odd modes, the transmission zero of the modifled SIR can be found, and the

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Cheng-Yuan Hung

Papers

A Hairpin Line Diplexer for Direct Sequence Ultra-Wideband Wireless Communications

A Tri-Band Bandpass Filter With Wide Stopband Using Asymmetric Stub-Loaded Resonators

Loss characteristics of silicon substrate with different resistivities

Design of a Compact Ultra-Wideband Bandpass Filter With an Extremely Broad Stopband Region

Design of a high band isolation diplexer for gps and wlan system using modified stepped-impedance resonators