• The Journal of Korean Institute of Communications and Information Sciences
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• v.40 no.12
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• pp.2461-2468
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• 2015

Sinuous antenna is utilized in a number of application like direction-finding system that require ultra wideband, but because of high input impedance of the antenna, it is difficult to design low-profile antenna and balun. In this study, we used Babinet's principle and proposed linear 2-arm slot sinuous antenna that is divided sinuous 6 cell with equal spacing between the most largest radius $R_1=31.83mm$ and the smallest radius $R_p=1.7mm$ instead of exponential 2-arm strip sinuous antenna for 2-18[GHz] frequency band to obtain low input impedance, and we have studied -10dB bandwidth of antenna when has been fed by $80{\Omega}$ instead of $188{\Omega}$ at feeder point. As a result, we have obtained return loss below than -10dB for about 4-18[GHz] frequency range in the case of slot antenna, but at all frequency band, return loss was above -10dB in the case of strip antenna.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.42 no.2
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• pp.374-382
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• 2017

This paper proposed a 2 stages 2-arm sinuous antenna that operates in frequency range 0.8-6GHz. The proposed antenna's total radius is 60mm, in which 1st stage's radius is 50mm which is designed as self-complementary structure(cell's angle width $90^{\circ}$) with 8 cell, and 2nd stage is composed of non-self-complementary structure with 0.5 cell of cell's angle width $720^{\circ}$ in the radius width 10mm. Measurement's result shows that -10dB return loss starts at 0.807GHz, but 1 stage 2-arm sinuous antenna that use the same radius starts at about 0.878GHz, so proposed the possibility of the miniaturization of the sinuous antenna.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.15 no.6
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• pp.239-244
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• 2015

Recently, Impulse radars using UWB technologies are widely use for measuring distance, or for transmitting uncompressed high resolution videos. However, since the UWB band spans over octave bands, it is not easy to design such a system. Wide band impedance matching is required for antennas and other RF area. In this study, we designed and fabricated sinuous antenna for 3~6 GHz octave band application. We also designed and attached a dielectric lens to improved the directional gain of the antenna. The gain of the antenna was 6~10 dBi. The dielectric lens attached sinuous antenna was used to transmit HD video data. The maximum reach distance was 90 meter with 10mW power.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.26 no.3
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• pp.257-267
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• 2015

This paper presents a ultra-wideband sinuous antenna that operates in a whole frequency range (0.824~5.85 GHz) of Cellular/GSM-800, GSM900, ISM, GPS, DCS/GSM1800, PCS/GSM1900, WCDMA/UMTS/IMT2000, WiBro, WLAN and WiMax. The proposed antenna, which is composed of two sinuous arms, is designed as a self-complementary structure in order to have frequency-independent characteristics. It also uses a wideband balun of Klopfenstein taper structure to match to $50{\Omega}$. Experimental results show that the -10 dB return loss bandwidth of the proposed antenna is 5.24 GHz that ranges from 0.76 to 6 GHz, which covers all the frequency bands of the various wireless services. Within the entire operating frequency range, the measured radiation patterns in both E-plane and H-plane show nearly constant bidirectional broadside beams and the maximum antenna gain is measured to fall between 2.32~6.01 dBi.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2014.10a
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• pp.484-487
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• 2014

In this paper, We describe antenna characteristics for efficiently detecting human signs using small, planar and low power antenna. Then we can measure biological signals including respiration, heart rate, blood pressure, and blood sugar, using UWB (Ultra Wide Band) pulses, while does not contact the human body. The antenna need stable and wideband impedance characteristic, because it use gaussian pulse signal. Usually it has trade-off between wideband impedance and gain. But we don't considered array type antennas because we want to need small size. Generally the antennas that classified as frequency independent satisfy our requirements. Frequency independent antennas include spiral, log-periodic, sinuous, and etc. These antennas are possible to have shape planar type. In this paper, We tested these kind antenna's characteristics in center frequency 5 GHz, Especially circular patch and sinuous antenna designed and analyzed.

• Journal of Advanced Navigation Technology
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• v.22 no.2
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• pp.123-132
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• 2018

In this paper, we design and fabricate a dual liner polarization sinuous antenna with improved cross polarization isolation (XPI). The proposed antenna is composed of four arm radiators for generating dual linear polarization and excited by wideband microstrip balun with Klopfenstein taper structure. Also, two-step cylindrical cavity structure is applied to reduce back radiation. Honeycomb-typed absorbing material is inserted into the cavity to reduce performance degradation by reflected wave. To enhance cross polarization isolation in low frequency band, resistors are adapted between outer arm and the rim of cavity. We confirmed that the fabricated antenna can be applied for polarization measurement due to improved XPI in the low band.