• Title/Summary/Keyword: Sideband Suppression

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Design and Fabrication of 5.5GHZ SSB optical modulator with polarization reversed structure (LiINbO3 기판의 분극반전을 이용한 5.5 GHz 대역 SSB 광변조기의 설계 및 제작)

  • Jeong, W.J.;Kim, W.K.;Yang, W.S.;Lee, H.M.;Lee, H.Y.;Kwon, S.W.
    • Korean Journal of Optics and Photonics
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    • v.17 no.2
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    • pp.175-180
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    • 2006
  • A single sideband(SSB) modulator operating at 5.5 GHz was fabricated by polarization inversion techniques. The dimension of domain inversion in a $LiINbO_3$ Mach-Zehnder structure was precisely controlled so that the RF signal applied on two Mach-Zehnder arms gives rise to $90^{\circ}$ effective phase difference. The single sideband suppression was maximized by optimization of the polarization status of the optical input and by the DC bias value. The fabricated device showed the center frequency of 5.8 GHz and the maximum sideband suppression of 33dB, where the bandwidth of 15 dB sideband suppression ranged over a 2.5 GHz span. The optical phase delay could be regulated by the DC bias voltage, fur example, the enhanced optical modulation sideband was distinctively switched from the upper sideband to the lower sideband by changing the DC bias voltage from 1.9 V to -10.6 V.

Implementation of Wideband SSM with Excellent Sideband and Carrier Suppression (우수한 측파대 및 반송파 억압을 갖는 광대역 단측파대 믹서의 구현)

  • Kim, In-Seon;Park, Young-Ju;Kim, Jang-Pyo;Jeon, Jeong-Il;Kim, Moo-Hoi
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.22 no.12
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    • pp.1097-1106
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    • 2011
  • In this paper, we present design method of wideband single-sideband mixer(SSM) with excellent sideband suppression and carrier suppression. We proposed SSM with 4-band split structure for uniform output flatness. From circuit simulation of this structure using Microwave OfficeTM, we got satisfactory results. We realized a SSM based on this results, then we experimented. The measured results show excellent agreements with the simulated results. We compared with two SSM's(target SSM(M Co. SM0218LC1CDC SSM) and our SSM) as well. The presented SSM is 3.35 times bigger, but sideband suppression is 3 dBc better and carrier suppression is 8 dBc better than those of comparative SSM, respectively.

Ring Resonator Based Band-pass Filter with Enhanced Sideband Suppression (사사이드밴드 억압비가 향상된 링 공진기형 대역통과 필터)

  • Kyoung, Un-Hwan;Kim, Gun-Duk;Lee, Sang-Shin;Eo, Yun-Seong
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.45 no.6
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    • pp.8-12
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    • 2008
  • A ring resonator based band-pass filter enabling enhanced sideband suppression was proposed and demonstrated. It is composed of a single-ring based band-pass section combined with a band-rejection section based on two different coupled rings. The sideband region of the transfer characteristics of the first band-pass filter section was selectively suppressed by means of the band-rejection section without causing any excessive insertion loss. As a result, the overall transfer characteristics of the proposed filter was unproved so that its sideband suppression was elevated to allow for sharper roll-off and narrower bandwidth. In this work, a conventional single-ring band-pass filter and a proposed filter including the band-rejection section were designed and fabricated. As for the achieved device performance, with the center frequency at about 4 GHz, the sideband suppression ratio was increased as much as 8 dB and the 3-dB bandwidth was reduced from 98 MHz to 48 MHz by about 51% with no remarkable excessive insertion loss as expected. And the quality factor of the device was increased by about 105%.

Thirty-two-tupling frequency millimeter-wave generation based on eight Mach-Zehnder modulators connected in parallel

  • Xinqiao Chen;Siyuan Dai;Zhihan Li;Wenyao Ba;Xu Chen
    • ETRI Journal
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    • v.46 no.2
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    • pp.194-204
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    • 2024
  • A new method is proposed to generate a 32-tupling frequency millimeter wave (MMW) with eight Mach-Zehnder modulators (MZMs) connected in parallel. Theoretical analyses and simulation experiments are conducted. The optical sideband suppression ratio (OSSR) of the obtained ±16th order optical sidebands are 61.54 dB and 61.42 dB, and the radio frequency spurious suppression ratios (RFSSRs) of the generated 32-tupling frequency MMW are 55.52 dB and 55.27 dB based on the theoretical analysis and simulation experiments, respectively; these outcomes verified the feasibility of the new method. The main parameters used to affect the stability of the generated signal are the modulation index and extinction ratio of MZM. Their effects on the OSSR and RFSSR of the generated signals are investigated when they deviate from their designed values. Compared with the other proposed methods for the generation of 32-tupling frequency MMW by MZM, our method has the best spectral purity and stability, and it is expected to have important MMW over fiber applications.

Ring Resonator Based Band-pass Filter with Enhanced Sideband Suppression (사이드밴드 억압비가 향상된 링 공진기형 대역통과 필터)

  • Kyoung, Un-Hwan;Kim, Gun-Duk;Lee, Sang-Shin;Eo, Yun-Seong
    • Proceedings of the IEEK Conference
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    • 2008.06a
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    • pp.195-196
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    • 2008
  • A ring resonator based band-pass filter enabling enhanced sideband suppression was proposed and demonstrated. It is composed of a single-ring based-pass section combined with a band-rejection section based on two different coupled rings. As for the achieved device performance, bandwidth was reduced from 98 MHz to 48 MHz by about 51% with no remarkable excessive insertion loss as expected. And the quality factor of the device was increased by about 105%.

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A CMOS Frequency Synthesizer Block for MB-OFDM UWB Systems

  • Kim, Chang-Wan;Choi, Sang-Sung;Lee, Sang-Gug
    • ETRI Journal
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    • v.29 no.4
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    • pp.437-444
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    • 2007
  • A CMOS frequency synthesizer block for multi-band orthogonal frequency division multiplexing ultra-wideband systems is proposed. The proposed frequency synthesizer adopts a double-conversion architecture for simplicity and to mitigate spur suppression requirements for out-of-band interferers in 2.4 and 5 GHz bands. Moreover, the frequency synthesizer can consist of the fewest nonlinear components, such as divide-by-Ns and a mixer with the proposed frequency plan, leading to the generation of less spurs. To evaluate the feasibility of the proposed idea, the frequency synthesizer block is implemented in 0.18-${\mu}m$ CMOS technology. The measured sideband suppression ratio is about 32 dBc, and the phase noise is -105 dBc/Hz at an offset of 1 MHz. The fabricated chip consumes 17.6 mA from a 1.8 V supply, and the die-area including pads is $0.9{\times}1.1\;mm^2$.

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A Flexible and Tunable Microwave Photonic Filter Based on Adjustable Optical Frequency Comb Source

  • Tran, Thanh Tuan;Seo, Dongsun
    • Journal of IKEEE
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    • v.19 no.1
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    • pp.27-32
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    • 2015
  • A flexible and tunable microwave photonic filter based on adjustable optical frequency comb source is demonstrated. We use a combination of a dual parallel Mach Zehnder modulator and an intensity modulator to generate fifteen comb lines with proper weights to implement a desired filter. The optical comb weights, corresponding to the tap coefficients of the filter, are flexibly changed by adjusting the operation parameters of the modulators. The achieved bandwidth and stopband attenuation of the tunable filter are 0.7 GHz and 20 dB, respectively. In addition, we overcome the undesired low frequency suppression appeared in a conventional scheme by applying a dual parallel Mach Zehnder modulator for single sideband suppressed carrier modulation.

Suppression of Current Harmonics with Triple Delta Sourced Winding and Novel Connection of Common-mode Filter (4권선 변압기의 삼중 델타 전원 연결과 새로운 커먼-모드 필터 연결방법을 이용한 전류 고조파 저감)

  • Ohn, Sungjae;Sul, Seung-Ki
    • Proceedings of the KIPE Conference
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    • 2015.07a
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    • pp.245-246
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    • 2015
  • 본 논문에서는 삼중 델타 전원과 새로운 커먼-모드 필터 결선을 통해 스위칭에 의한 고조파를 저감하는 방법을 제안한다. PWM에 의해 생성되는 측대파 고조파(Sideband harmonics) 위상을 분석함으로써, 인터리빙 운전 시 삼중 델타 전원 연결과 제안된 커먼모드 필터가 측대파 고조파 전류를 크게 저감할 수 있음을 보인다. 3개의 고정자 권선을 가지는 영구자석 전동기를 이용하여 제안된 필터의 유효성을 검증하였다.

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Phase Noise Characterization with Optical Carrier Suppression Level on Continuous Wave in the Ranges of Millimeter Waves Generated by Photomixing of Optical Double Sideband-Suppressed Carrier(DSB-SC) (광 반송파가 억압된 양측 대역 방식의 광 혼합을 통하여 발생된 밀리미터파 대역 연속파에서 광 반송파 억압 레벨에 따른 위상 잡음 특성 분석)

  • Kim, Sung-Il;Kang, Kwang-Yong
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.20 no.9
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    • pp.974-982
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    • 2009
  • Photomixing techniques beating two optical signals with different wavelengths and strong correlations are also very useful techniques to make a continuous wave(CW) signals in the range of millimeter(mm) and terahertz(THz) frequencies. An optical double sideband-suppressed carrier(DSB-SC) technique is one of the popular techniques to generate two optical signals with different wavelengths and strong correlations. DSB-SC signals with strong correlations are generated by a CW modulation of an optical carrier with a local oscillator and an optical modulator. In the previous parers related the DSB-SC for producing the CW signals within the range of mm and THz frequencies, there have been no reports why the optical carrier should suppress. In order to clear that, we have analyzed and measured the characteristics of the mm-wave CW signals made by the DSB-SC photomixing in this paper. From our analysis and measurement results, compared with the case of the DSB with the maximized optical carrier, the power and phase noise have improved about 23.9 dB and 21 dBc/Hz(@ 1 MHz offset frequency) in the case of the DSB with the minimized optical carrier (that is to say, the DSB-SC). Consequently, it is evident reason that the optical carrier should sufficiently suppress to obtain the mm-wave CW signals with the high power and low noise. This paper has given very helpful data to make mm- and THz-wave CW signals using photomixing techniques with the DSB-SC because the reason why the optical carrier should be suppressed is reported in this paper based on the numerical and experimental results.

A 14-band MB-OFDM UWB CMOS LO Generator (CMOS 공정을 이용한 14개 LO 신호를 발생시키는 MB-OFDM UWB용 LO 생성 회로 블록 설계)

  • Seo, Yong-Ho;Shin, Sang-Woon;Kim, Chang-Wan
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.47 no.11
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    • pp.65-71
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    • 2010
  • This paper presents a 14-band LO generator architecture for MB-OFDM UWB systems using 3.1 GHz~10.6 GHz frequency band. The proposed LO generator architecture has been consisted of only one PLL and the fewest nonlinear components to generate 14 LO signals with high purity while consuming low dc power consumption. In addition, major spurious generated from the LO generator have been located in the out of UWB band. The proposed LO generator has been implemented in a $0.13-{\mu}m$ CMOS technology and consumes a dc power consumption of 93~103 mW from a 1.5 V supply. The simulation results show an in-band spurious suppression ratio of more than 41 dBc and a band-switching time of below 3 nsec.