• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.27 no.5
• /
• pp.424-429
• /
• 2016

This paper presents dual-mode ring-resonator bandpass filter using LUC of artificial-transmission-lines. The conventional ring-resonator bandpass filter has limitation in miniaturization because the conventional ring-resonator is based on a one wavelength operation, and problem due to undesire harmonics. The ring-resonator bandpass filter is miniaturized and show higher order mode rejection by configuring a ring-resonator with LUC of artificial-transmission-lines. The two-stage bandpass filter is designed and fabricated with a ring-resonator and input/output interdigital coupled line. A fabricated filter shows dual-mode, rejection of whole ultra wide band, sharp skirt characteristics and has ring area reduced by 60 % compared to the conventional ring-resonator bandpass filter.

• Journal of the Korean Institute of Telematics and Electronics D
• /
• v.36D no.8
• /
• pp.27-35
• /
• 1999

A radius of ring resonator is determined by the resonant frequency. Resonant frequencies of resonators with the circumference which is integer times of wave length are not same the expected. In this paper, we suggest the design method of a ring resonator with coupling gap, which has the resonant frequency of desire. The equation which can make reduction of the radius of the resonators depending on the gap space is derived by the method of transmission line analysis. The criterion is suggested to determine the radius of the resonator in accordance with relative permittivity. A ring resonator by the proposed method is as small as one-third of basic ring in size and it has the resonant frequency of desire. T-type coupling line is designed to obtain large attenuation of $S_{11}$ at pass-band. These coupling line capacitances are very lower than the gap capacitances, it does not affect the resonant frequency.

• Journal of the Institute of Electronics Engineers of Korea SD
• /
• v.44 no.2
• /
• pp.46-54
• /
• 2007

We have fabricated and characterized MMI (Multimode Interference) coupled ring resonator with the total internal reflection mirrors and the semiconductor optical amplifier for the integration of the WDM (Wavelength Division Multiplexing) system. The TIR (Total Internal Reflection) mirrors were fabricated by self-aligned process and had losses of about 0.71 dB per mirror. Coupling in and out of a resonator was achieved using the extremely small MMI couplers. The MMI length and width used in the experiment were $119{\mu}m$ and $9{\mu}m$, respectively. The resulting FSR (Free Spectral Range) and on-off ratio were approximately 1.333 nm (162 GHz) and 13 dB, respectively.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
• /
• 2002.11a
• /
• pp.82-85
• /
• 2002

본 논문에서는 접지면에 어퍼쳐를 갖는 협대역 hairpin-comb 대역 통과 여파기를 제안하였다. Hairpin-comb 공진기는 두 공진기 사이의 간격이 매우 좁더라도 약한 커플링을 유지하는 특성이 있으므로 협대역 대역통과 여파기 제작시 여파기의 전체적인 크기를 작게 할 수 있는 장점이 있다. 그러나 일반적인 마이크로스트림에서는 공진기 사이가 최소한의 거리가 되더라도 커플링이 너무 미약하여 사용할 수 없다, 그러므로 접지면의 어퍼쳐를 사용하여 약한 커플링을 보상함으로써 일반 마이크로 스트립에서도 협대역을 대역통과 여파기를 제작할 수 있었다. 또한 공진기 사이의 거리변환 없이 어퍼쳐의 크기에 의해서 커플링을 조절함으로써 전체 여파기의 크기를 고정시킨 상태에서 대역폭을 조절할 수 있는 장점이 있다. 본 논문에서는 중심 주파수가 1.78 ㎓ 이고 대역폭이 62MHz(3.5%)인 여파기를 제작하였다.

• Journal of the Institute of Electronics Engineers of Korea SD
• /
• v.44 no.11
• /
• pp.26-35
• /
• 2007

We characterized the properties of the fabricated filter with the total internal reflection mirror (TIR) in the rectangular ring resonator and very small multimode interference (MMI) couplers on an InP material platform for photonic integrated circuits. Coupling power in and out of a resonator is increased by using an optimum MMI length of 110 ${\mu}m$ and a width of 9 ${\mu}m$, respectively. The semiconductor optical amplifier with the length of 120 ${\mu}m$ is integrated in the resonator to compensate the loss of the internal waveguide and the TIR mirror. A free spectral range of approximately 2 nm (244 GHz) is observed with an on-off ratio of 13 dB. The curve fitting also yields the power coupled per pass as 42%. To reach critical coupling at this coupling level would require a round trip loss of about 2.4 dB.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.20 no.2
• /
• pp.129-134
• /
• 2009

In this paper, we proposed a miniaturized Balun-BPF structure using semi-lumped line The conventional Ring Balun-BPF relatively has a big size structure because they consist of two ring resonators, wide line width ring-resonators for low loss and $\lambda/4$transmission line inverters. The ring resonators are miniaturized to 1/4 size by semi-lumped line and we added triangle patches in the ring resonator for compact Balun-BPF structure. The fabricated Balun-BPF is miniaturized to 1/4 size and contains symmetrical output characteristics of balance ports.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.10 no.6
• /
• pp.653-658
• /
• 2015

In this paper, the Square Split Ring Resonator(: SRR) of Defected Ground Structure(: DGS), applicable to MMIC(: Monolithic Microwave Integrated Circuit) design, is proposed. The mathematical method to solve the equivalent parameter of the resonator from the measured results of resonator is introduced in this paper. To verify the method, SRR-DGS resonator with 2.95 GHz center frequency is fabricated, for measuring characteristics and calculating the equivalent parameter. The result from this process is compared with the data of the ADS simulation, and as a result both were identical.

• Korean Journal of Optics and Photonics
• /
• v.20 no.1
• /
• pp.41-47
• /
• 2009

We report the spectral characteristics of Multimode Interferometer (MMI)-coupled semicondoctor square ring resonators. The epitaxial layers of the proposed semiconductor ring resonator consists of $1.55{\mu}m$ GaInAsP-InP multiple quantum wells. The lasing characteristics were observed by varying the structure parameters of the MMI-coupled square ring resonators. It is concluded that the MMI-coupled scheme selects a single spectral lasing mode in the double square ring cavities.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.14 no.1
• /
• pp.20-26
• /
• 2003

This paper presents hairpin-comb bandpass filter using ground aperture. Hairpin-comb resonator maintains the weak coupling though the space between two resonators is very small. This has the good merit that the entire filter size is small for narrowband bandpass filter. The coupling between two hairpin-comb resonators so very weak that can't be applicable to general microstrip. We compensate the coupling by using ground aperture. It makes the hairpin-comb filter possible that can be applicable to general microstrip. Also it has the good merit which adjusts the bandwidth by changing the size of aperture without changing the space. In this paper, we fabricate the bandpass filter, which has 1.78 GHz center frequency and 62 MHz (3.5%) fractional bandwidth.

• Korean Journal of Optics and Photonics
• /
• v.10 no.6
• /
• pp.524-526
• /
• 1999

It is observed that the mode spacing of an cxternal cavity semiconducror laser can be altered dramatically by the insertion of an intracavity etalon. 111e mode spacing is decreased as a function of etalon's reflectivity and this effect is quantitatively explained by an analysis of resonant modes. We abo show that this effect provides a precise and convenient alternative for determining the coating reflectivity of a high reflectivity etalon. talon.