A Coarse Frequency Offset Estimation Based on the Differential Correlation in DAB Systems

Han Jong Kim,Jong Ho Paik,Cheol Hee Park,Young Hwan You,Min Chul Ju,Jin Woong Cho 한국전자파학회JEES 2001 Journal of Electromagnetic Engineering and Science Vol.1 No.1

Miniaturization of SIW-Based Linearly Polarized Slot Antennas for Software-Defined Radar

Jun Yong Han,Seong Sik Yoon,Jae Wook Lee 한국전자파학회JEES 2016 Journal of Electromagnetic Engineering and Science Vol.16 No.4

Two substrate integrated waveguide (SIW)-based antennas for the application of software-defined radar are proposed and investigated herein. It is usually well known that SIWs are easily integrated, lightweight, have low insertion loss, and low interference levels compared to conventional microstrip structures. The primary function of the proposed antennas is to transmit continuous waves for indoor motion detection, with the lowest amount of loss and an appropriate amount of gain. Moreover, the results of this study show that the size of the antenna can be reduced significantly (i.e., by about 40%) by applying a meander line structure. The operating frequencies of the proposed antennas are both within the industrial, scientific, and medical band (i.e., 2.4–2.4835 GHz). Measured results of return loss are -16 dB and -20 dB at 2.435 GHz and 2.43 GHz, respectively, and the measured gain is 8.2 dBi and 5.5 dBi, respectively. Antenna design and verification are undertaken through commercially available full electromagnetic software.

Novel New Approach to Improve Noise Figure Using Combiner for Phase-Matched Receiver Module with Wideband Frequency of 6–18 GHz

Yuseok Jeon,Sungil Bang 한국전자파학회JEES 2016 Journal of Electromagnetic Engineering and Science Vol.16 No.4

This paper proposes the design and measurement of a 6–18 GHz front-end receiver module that has been combined into a one- channel output from a two-channel input for electronic warfare support measures (ESM) applications. This module includes a limiter, high-pass filter (HPF), power combiner, equalizer and amplifier. This paper focuses on the design aspects of reducing the noise figure (NF) and matching the phase and amplitude. The NF, linear equalizer, power divider, and HPF were considered in the design. A broadband receiver based on a combined configuration used to obtain low NF. We verify that our receiver module improves the noise figure by as much as 0.78 dB over measured data with a maximum of 5.54 dB over a 6–18 GHz bandwidth; the difference value of phase matching is within 7° between ports.

Low-Profile Planar Inverted-F Antenna for Ultrawideband Applications

Junsik Yun,Jaehoon Choi 한국전자파학회JEES 2016 Journal of Electromagnetic Engineering and Science Vol.16 No.4

In this paper, a low-profile planar inverted-F antenna (PIFA) for ultrawideband (UWB) applications is proposed. The antenna consists of a PIFA and a ground plane with a slot. The addition of the slot not only improves the impedance matching of the PIFA but also forms an additional resonance. Therefore, the proposed antenna has a wideband characteristic covering the full UWB frequency range (3.1 GHz to 10.6 GHz) and a stable and nearly omnidirectional radiation pattern. The antenna also has a smaller volume and thickness compared to previous UWB PIFAs.

A CMOS 180-GHz Signal Source with an Integrated Frequency Doubler

Jungsoo Kim,Myeong-Gyo Seo,Jae-Sung Rieh 한국전자파학회JEES 2016 Journal of Electromagnetic Engineering and Science Vol.16 No.4

Development of a V-Band Millimeter-Wave Source Module

Jae-Yong Kwon,Dong-Joon Lee,Aditia Nur Bakti,Windi Kurnia Perangin Angin 한국전자파학회JEES 2016 Journal of Electromagnetic Engineering and Science Vol.16 No.4

KRISS-V, a V-band millimeter-wave source module for a primary RF power standard and calibration system developed by the Korea Research Institute of Standards and Science is here presented. The output power of KRISS-V is several times higher than that of commercial amplifier/multiplier chains and is highly stable (the standard deviations of output power are less than 0.01% in the worst case). The spectral purity of KRISS-V is high enough to consider it a single-tone signal generator. We also added programmable attenuation capability to KRISS-V for remote power control. Moreover, the in-house source module is cost-effective and adaptable to various measurement schemes. The structure of the model as well as detailed component information are introduced so that it can be reproduced.

Synthesis of Bulk Medium with Negative Permeability Using Ring Resonators

Bomson Lee,Gunyoung Kim 한국전자파학회JEES 2016 Journal of Electromagnetic Engineering and Science Vol.16 No.2

This paper presents simple expressions for the effective permeability of bulk metamaterial consisting of ring resonators (RRs) or split ring resonators (SRRs) based on the convenient geometrical factors of the structure compared with wavelength. The resonant frequency dependence of the medium permeability, including loss effects, is analyzed in detail. Inverting the analysis equations, useful design (or synthesis) equations are derived for a systematic design process with some examples. This paper may particularly be useful for the design of a bulk metamaterial with a specific negative relative permeability at a desired frequency. The loss of metamaterials consisting of RRs (or SRRs) is also analyzed over a wide frequency band from 10 MHz to 10 THz.

Optimum Array Configuration to Improve Null Steering Time for Mobile CRPA Systems

Hosung Choo,Seung Mo Seo,Jong-Chul Hyun,Gangil Byun 한국전자파학회JEES 2016 Journal of Electromagnetic Engineering and Science Vol.16 No.2

This paper proposes an optimum array configuration to improve null steering time for mobile controlled reception pattern antenna (CRPA) systems. The proposed array consists of a single reference element at the center and nine auxiliary elements arranged in a circular array. The array radius and the vertical positions of the center element are optimized using a genetic algorithm in conjunction with a constrained least-mean-square algorithm. The results demonstrate that the proposed array is suitable for mobile CRPA systems without significant side nulls in satellite directions.

Proposal of an Algorithm for an Efficient Forward Link Adaptive Coding and Modulation System for Satellite Communication

Sung-Yong Hong,Hyun-Ho Kim,Deock-Gil Oh,Joon-Gyu Ryu 한국전자파학회JEES 2016 Journal of Electromagnetic Engineering and Science Vol.16 No.2

This paper proposes the algorithm for forward link adaptive coding and modulation (ACM) and the detailed design for a satellite communication system to improve network reliability and system throughput. In the ACM scheme, the coding and modulation schemes are changed by as much as the channel can provide depending on the quality of the communication link. To implement the forward link ACM system in the Ka-band, channel prediction and modulation/coding decision methods are proposed and simulated. The parameters of the adaptive filter predictor based on the least mean square are optimized, the minimum mean square error of the channel predictor is 0.0608 when step size and the number of filter tap are 0.0001 and 4, respectively. A test-bed is set up to verify the forward link ACM system, and a test is performed using a Ka-band satellite (i.e., Communication, Ocean, and Meteorological Satellite [COMS]). This test verifies that the ACM scheme can increase the system throughput.

Numerical Implementation of Representative Mobile Phone Models for Epidemiological Studies

Elisabeth Cardis,Hyung-Do Choi,Seon-Eui Hong,Byungje Lee,Sooyung Lee,Yonghyun Yoon,Ae-Kyoung Lee 한국전자파학회JEES 2016 Journal of Electromagnetic Engineering and Science Vol.16 No.2

This paper describes an implementation method and the results of numerical mobile phone models representing real phone models that have been released on the Korean market since 2002. The aim is to estimate the electromagnetic absorption in the human brain for casecontrol studies to investigate health risks related to mobile phone use. Specific absorption rate (SAR) compliance test reports about commercial phone models were collected and classified in terms of elements such as the external body shape, the antenna, and the frequency band. The design criteria of a numerical phone model representing each type of phone group are as follows. The outer dimensions of the phone body are equal to the average dimensions of all commercial models with the same shape. The distance and direction of the maximum SAR from the earpiece and the area above –3 dB of the maximum SAR are fitted to achieve the average obtained by measuring the SAR distributions of the corresponding commercial models in a flat phantom. Spatial peak 1-g SAR values in the cheek and tilt positions against the specific anthropomorphic mannequin phantom agree with average data on all of the same type of commercial models. Second criterion was applied to only a few types of models because not many commercial models were available. The results show that, with the exception of one model, the implemented numerical phone models meet criteria within 30%.