• 한국전자파학회:학술대회논문집
• /
• 한국전자파학회 2005년도 종합학술발표회 논문집 Vol.15 No.1
• /
• pp.367-370
• /
• 2005

In this paper, we made a Singly Fed patch which is the fittest at the feeding part. And we found out return loss and radiation pattern about dielectric rod array antenna which has six's passive element to shape FTEP(Flat-topped element pattern) after we analyzed the characters of singly dielectric rod antenna. We show the conclusion that has the optimum return loss and more flat radiation pattern.

• 한국전자파학회:학술대회논문집
• /
• 한국전자파학회 2005년도 종합학술발표회 논문집 Vol.15 No.1
• /
• pp.323-328
• /
• 2005

The paper describes a meander antenna using magneto-dielectric composite for 433.92 MHz band. The antenna with magneto-dielectric material in this paper is suggested for miniaturization of antenna size. The return loss of meander antenna is achieved by optimizing the permittivity, $\varepsilon_r$=1.71-j0.004 and permeability, $\mu_r$=2.39+j2.58. Over all dimension of the antenna is $51\times11\times1.6mm$. The return loss and gain are -41 dB, -5dBi, respectively at 433.92 MHz.

• 한국전자파학회논문지
• /
• 제14권2호
• /
• pp.104-110
• /
• 2003

광대역에서 동작되는 간단한 180$^{\circ}$ MMIC 위상변위기를 제안하였다. 제안된 회로는 1개의 Lange 커플러와 2개의 PIN 다이오드만으로 구성되어 있다. 2-6 GHz 대역에서 측정된 위상변위기는 최대 위상오차가 13$^{\circ}$이며 3.2 dB의 최대 삽입손실과 6.3 dB의 최소 반사손실을 보였다.

• Journal of electromagnetic engineering and science
• /
• 제7권1호
• /
• pp.42-46
• /
• 2007

This paper presents a linear amplitude equalizer developed to secure the linearity of the slope of the amplitude over the frequency band ranging $2\sim18\;GHz$. The circuit model is featured by the resistor placed between each pair of a transmission-line and a stub. The design includes finding the values of resistors and stubs to have the optimal linear slope and return loss performances. The measured data show the acceptable performances of the slope variation and return loss over $2\sim18\;GHz$.

• Journal of electromagnetic engineering and science
• /
• 제8권3호
• /
• pp.96-99
• /
• 2008

This paper describes a $0.13-{\mu}m$ CMOS RF switch for $3{\sim}5$ GHz UWB band(mode 1). It can improve isolation characteristics between ports by using deep n-well RF devices while their source and body terminals are separated. From the measurement results, the proposed T/R switch is comparative to the on-wafer probing measurement results of the series-shunt T/R switches. When the proposed T/R switch operates as Tx mode, measured insertion loss from Tx to output port is less than 1.5 dB and isolation between Tx and Rx is more than 27 dB for $3{\sim}5$ GHz. Return loss for the Tx port is more than -10 dB and input P1dB is +10 dBm.

• 한국전자파학회논문지
• /
• 제8권3호
• /
• pp.289-296
• /
• 1997

본 논문에서는 대표적인 희절공식들을 살펴보고, 쐐기 형태의 구조물에 대한 희절손실 예측치를 비교해 모았다. 또한 시뮬레이션 결과를 측정치와 비교, 분석하였다. 은 산란체가 의절체 부근에 존재하는 실제 환경에서 수직편파에 대한 의절손실은 단순한 knife-edge 공식이 측정치와 잘 일치하였다. 일치하였다.

• 전기학회논문지
• /
• 제57권11호
• /
• pp.2127-2130
• /
• 2008

In this paper, a tunable bandpass filter with mutual inductive coupling circuits is newly designed and demonstrated for UHF TV tuner ranged from Ch.14(473MHz) to Ch.69(803MHz) applications. Conventional HF tuning circuit with an electromagnetic bandpass filter has several problems such as large size, high volume and high cost, since the electromagnetic filter is comprised of several passive components and air core inductors to be assembled and controlled manually. To address these obstacles, peaking chip inductor was newly applied for constructing the mutual inductive coupling circuit. The proposed circuit was newly and optimally designed, since the chip inductor showed lower components Q-value than the air core inductor. A varactor diode has been also used to fabricate the proposed tunable bandpass filter for RF tuning circuit. The fabricated tunable filter exhibited low insertion loss of approximately -3dB, high return loss of below -10dB, and large tuning bandwidth of 330MHz.

• Journal of electromagnetic engineering and science
• /
• 제15권4호
• /
• pp.206-212
• /
• 2015

This paper introduces new wideband antenna-filter-antenna (AFA) uniform arrays that can be utilized as frequency selective surfaces (FSS) with low loss and sharp roll-off response, which are highly desirable characteristics for millimeter wave applications. The design adopts a simple 3-layer single polarization structure consisting of two patch antennas and a resonator. Both simulations and measurements are used to characterize the performances of the proposed design. Overall results show 18.5% 10-dB bandwidth. For the targeted band the insertion loss is less than 0.2 dB. Possible applications include quasi-optical amps, grid mixers and radomes for aircraft radar antennas.

• 한국전자파학회:학술대회논문집
• /
• 한국전자파학회 2003년도 종합학술발표회 논문집 Vol.13 No.1
• /
• pp.140-144
• /
• 2003

To investigate failure analysis of surface acoustic wave (SAW) filter for radio frequency, high temperature storage test was carried out. The failure criteria were insertion loss at passband and rejection level at stopband. As a result, the insertion loss at passband increase about 4 dB was due to damages of interdigital transducer (IDT). That is caused by poor adhesion between metal electrode(AI) and piezoelectric substrate and defects on a manufacturing process. This result indicates that good adhesion between electrode and ceramic substrate is important factor And also we investigated the demage factors of electrode. Screen possible of saw filter using high temperature storage test(HTOL) in the manufacturing phase be presented.

• 한국전자파학회:학술대회논문집
• /
• 한국전자파학회 2003년도 종합학술발표회 논문집 Vol.13 No.1
• /
• pp.256-259
• /
• 2003

In this paper, a design of multi-layered BPF(bandpass filter) using LTCC(Low Temperature Co-fired Ceramic) process by a lumped-elements is proposed for SOP(system-on-a-chip) of wireless communication systems. The proposed BPF improved a characteristic of rejection band to build an attenuation pole caused by structurally adjacent co-inductance and coupling. The simulation data shows a bandwidth of 90MHz from a center frequency of 2.4GHz, a return loss of 27dB, an insertion loss of 3.2dB, and an attenuation of at least 20dBc at $f_0{\pm}250MHz$. Simulations have used serenade circuit simulation and HFSS EM simulation.