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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
> Journal Vol & Issue
Journal of electromagnetic engineering and science
Journal Basic Information
Journal DOI :
The Korean Institute of Electromagnetic Engineering and Science
Editor in Chief :
Volume & Issues
Volume 5, Issue 4 - Dec 2005
Volume 5, Issue 3 - Sep 2005
Volume 5, Issue 2 - Jun 2005
Volume 5, Issue 1 - Mar 2005
Selecting the target year
A Simple If In-Phase Combiner and Its Performance for Point-to-Point Radio Relay System with Space Diversity
Suh Kyoung-Whoan ;
Journal of electromagnetic engineering and science, volume 5, issue 1, 2005, Pages 1~7
The implementation of a simple analog in-phase combiner is presented for a high capacity radio relay system with space diversity. It provides good performance in terms of simple hardware and easy control, and measured results are in good agreement with simulated ones. To suggest practical applications, signatures with/without diversity are measured for STM-1 signal of 64-QAM radio relay system combined with a 13-tap equalizer, and they provided more than 25 dB fade depth at 10
BER under the frequency selective fading condition.
An InGaP/GaAs HBT Monolithic VCDRO with Wide Tuning Range and Low Phase Noise
Lee Jae-Young ; Shrestha Bhanu ; Lee Jeiyoung ; Kennedy Gary P. ; Kim Nam-Young ;
Journal of electromagnetic engineering and science, volume 5, issue 1, 2005, Pages 8~13
The InGaP/GaAs hetero-junction bipolar transistor(HBT) monolithic voltage-controlled dielectric resonator oscillator(VCDRO) is first demonstrated for a Ku-band low noise block down-converter(LNB) system. The on-chip voltage control oscillator core employing base-collector(B-C) junction diodes is proposed for simpler frequency tuning and easy fabrication instead of the general off-chip varactor diodes. The fabricated VCDRO achieves a high output power of 6.45 to 5.31 dBm and a wide frequency tuning range of ]65 MHz( 1.53
) with a low phase noise of below -95dBc/Hz at 100 kHz offset and -115 dBc/Hz at ] MHz offset. A]so, the InGaP/GaAs HBT monolithic DRO with the same topology as the proposed VCDRO is fabricated to verify that the intrinsic low l/f noise of the HBT and the high Q of the DR contribute to the low phase noise performance. The fabricated DRO exhibits an output power of 1.33 dBm, and an extremely low phase noise of -109 dBc/Hz at 100 kHz and -131 dBc/Hz at ] MHz offset from the 10.75 GHz oscillation frequency.
A Technique for Broadbanding the CPW-Fed Bow-Tie Slot Antenna
Kim Sung-Hak ; Wen Lijun ; Ko Han-Woong ; park Dong-Hee ; Ahn Bierng-Chearl ;
Journal of electromagnetic engineering and science, volume 5, issue 1, 2005, Pages 14~20
In this paper, a technique is presented for broadbanding the bow-tie slot antenna fed by a CPW(coplanar waveguide). The bandwidth performance of existing bow-tie slot designs is greatly enhanced by optimizing the slot shape and properly adjusting the characteristic impedance of the coplanar waveguide feeding the slot. To connect the 50-ohm input coaxial line to the CPW feed line, a linear taper in the CPW is employed. The designed antenna shows a 3.5
10.0 GHz impedance bandwidth, a 3.5
6.0 GHz pattern bandwidth, and a 5.5
7.5 dBi gain over 3.5
6.0 GHz. Above 6.0 GHz, the antenna radiation pattern appreciably deviates from the typical dipolar pattern.
Efficient Design of Waveguide Filters Reducing Modal Interference through Cross-Shaped Slots
Kahng Sungtek ;
Journal of electromagnetic engineering and science, volume 5, issue 1, 2005, Pages 21~25
In this paper, a new method is suggested to improve the frequency responses of dual-mode waveguide-filters that employ cross-shaped slots. In accordance with this method, regarding one cross-shaped slot between two cavities, the horizontal(vertical) mode in one cavity can be designed to influence far less the vertical(horizontal) mode in cavity. Therefore, it improves the overall performances. A 4th-order dual-mode filter is taken as an example and it validates the method.
Phase Offset Enumeration Method with Error Detection and Its Application to Synchronization of PN Sequences
Song Young-Joan ;
Journal of electromagnetic engineering and science, volume 5, issue 1, 2005, Pages 26~30
It is important to know phase offsets of PN(Pseudo Noise) sequences in spread spectrum communications since the acquisition is equivalent to making a phase offset between a receiving PN sequence and a PN sequence of local PN generator be identical. In this paper, a phase offset enumeration method for PN sequences with error detection, and its application to the synchronization are proposed. The phase offset enumeration for an n-tuple PN sequence and its error detection are performed when one period of the sequence is received. Once the phase offset of the receiving sequence is calculated, we can easily accomplish the synchronization by initializing shift registers of a local PN generator according to the phase offset value. The mean acquisition time performance of the proposed scheme was derived analytically. Since this synchronization scheme can be realized by using simple circuit and acquires very rapid acquisition in high SNR but shows performance degradation in low SNR, it can be especially useful in indoor and office environments.
Low Profile Dual-Polarized Antenna for SDARS Application
Hong Young-Pyo ; Kim Jung-Min ; Jeong Soon-Chul ; Kim Dong-Hyun ; Yook Jong-Gwan ;
Journal of electromagnetic engineering and science, volume 5, issue 1, 2005, Pages 31~35
This paper presents low form factor dual polarized antenna incorporating low profile annular ring patch antenna having 90
phase delay element for circular polarization(CP) and a reactive-loaded monopole linear polarized(LP) antenna. Both types of receiving antennas operate in the same frequency region from 2.320 GHz to 2.345 GHz, while different polarizations are used to take advantage of polarization diversity. The proposed CP antenna has good broadside radiation patterns, while the LP antenna reveals monopole-like radiation patterns. The gains of the antennas are measured to be 1.93 dBi and 2.24 dBi for CP and LP, respectively.
Optimal Position of Optical Phase Conjugator for Compensation of Distorted WDM Signals with Initial Frequency Chirp
Lee Seong-Real ; Choi Byung-Ha ; Chung Myung-Rae ;
Journal of electromagnetic engineering and science, volume 5, issue 1, 2005, Pages 36~42
In this paper, the optimal position of optical phase conjugator(OPC) excellently compensating distorted WDM channels with initial frequency chirp due to both chromatic dispersion and self phase modulation(SPM) is numerically investigated. Highly-nonlinear dispersion shifted fiber(HNL-DSF) is used as a nonlinear medium of OPC in order to widely compensate WDM signal band. It is confirmed that if the OPC position was shifted from mid-way of total transmission length dependence on the initial frequency chirp as well as modulation format and fiber dispersion coefficient, it is possible to cancel the performance degradation owing to the initial frequency chirp. Using proposed configuration, it is possible to remove all in-line dispersion compensator, reducing span losses and system costs in the long-haul broadband WDM systems.
Applications of a Chirping and Tapering Technique on Photonic Band-Gap(PBG) Structures for Bandwidth Improvement
Tong Ming-Sze ; Kim Hyeong-Seok ; Chang Tae-Gyu ;
Journal of electromagnetic engineering and science, volume 5, issue 1, 2005, Pages 43~47
Microwave or optical photonic band-gap(PBG) structures are conventionally realized by cascading distributive elements in a periodic pattern. However, the frequency bandwidth obtained through such plainly periodic arrangement is typically narrow, corporate with a relatively high rejection side-lobe band. To alleviate such problems, a design involving a chirping and tapering technique is hence introduced and employed. The design has been applied in both a planar stratified dielectric medium as well as a strip-line transmission line structure, and results are validated when compared with the corresponding conventional PBG structure.