• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.14 no.5
• /
• pp.249-254
• /
• 2014

In this paper, minimizing of a parabolic edge planar monopole antenna by scaling method is presented. With the aid of a matching step and discontinuous CPW, the antenna easily adjusts the impedance matching. We used an FR4 dielectric substrate with a dielectric constant of 4.4. The dimensions of the antenna are $26mm{\times}31mm{\times}1.6mm$. A return loss value of more than 10dB was found in the 2.37GHz to 10.52GHz (8.15GHz) range of the antenna fed by the discontinuous CPW. The radiation pattern is about the same as that of the dipole antenna at all frequencies. Configuration elements of the antenna except feed part were reduced into the same rate. So, the size of the antenna was decreased and a broadband property was maintained. Therefore, the self-complementary characteristic of the antenna was confirmed. While satisfying the UWB band, having the smallest size in the antenna miniaturized by scaling;when scale was 0.6. The dimensions of the antenna are $15.6mm{\times}18.6mm{\times}1.6mm$. The return loss was more than 10 dB of the measured result in the range of 3.07GHz to 12.59GHz (9.52GHz).

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.14 no.2
• /
• pp.157-167
• /
• 2003

In this paper, to reduce the resonant length of patch, microstrip patch antenna of linear polarization which is suppressed at two radiation edges is designed and fabricated at the frequency of 1.575 GHz. The result is like that the resonant length of patch is 45 mm and the length reduction effect is 43.8 % when it is compared with that(80 mm) of plane type. The gain is 4.4 dBd and -3 dB beamwidths are 112$^{\circ}$ and 66$^{\circ}$ in the E-plane and H-plane, respectively. Also, to reduce the size of patch, microstrip patch antennas those are suppressed at four radiating comers are designed and fabricated at the same frequency in the linear and circular polarization, respectively. For linear polarization, at the 1.2 of width/length(W/L) ratio, the patch area is 53 mm $\times$ 63.6 mm and the size reduction effect is 56.1 % when compared with that(80 mm $\times$ 96 mm) of plane type. The gain is 4.3 dBd and the -3 dB beamwidths are 120$^{\circ}$ and 78$^{\circ}$ in the E-plane and H-plane, respectively. For circular polarization, the patch size(54.2 mm $\times$ 61.5 mm) is reduced by 47.2 % than that(76 mm $\times$ 83 mm) of plane type. -3 dB beamwidth of horizontal polarization in the z-x plane and vortical polarization in the y-z plane are 108$^{\circ}$ and 93$^{\circ}$, respectively and this means the increasement in both planes by 52$^{\circ}$ and 27$^{\circ}$ than those of plane type. The maximum gain is 2.5 dBd in the horizontal polarization in the z-x plane. Axial ratio is 1.5 dB at 1.575 GHz and the 2 dB axial ratio bandwidth(ARBW) is 20 MHz(1.3 %).

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.18 no.1
• /
• pp.1-13
• /
• 1989

The present study was designed to examine the effect of dietary fish oil on blood pressure and lipid status of serum. Weanling SHRs and normotensive Wistars were fed a diet containing 5%(w/w) mackerel oil(MO), soybean oil(SO) or beef tallow(BT) for 8 weeks. Growth rate was not significantly different among three dietary groups, but that of SHRs was silightly lower than that of Wistars. SHRs showed higher systolic blood pressure than Wistar rats from the beginning and become hypertensive (over 150mmHg) after 6 week s of feeding period. The MO group of SHRs showed the lowest blood pressure at the 8th week of feeding period but that of Wistars showed similar values with other groups. Tissue weights of liver, heart and kidney were not different amongdietary aroups in Wistars and SHRs. However, heart and kidney weights of SHRs were significantly higher than those of Wistars. Microscopic examination revealed that endomysium of heart tissue and urinary space of kidney were narrowed in SHRs. Serum total and HDL-cholesterol showed similar values among three different dietary fat groups but triglyceride levels were significantly low in MO groups. HDL-cholesterol levels of SHRs were lower than those of Wistars, as well as the fractions of total HDL, the sum of HDL and $HDL_{2+3}$, while VLDL fractions were higher in SHRs. MO groups had the lower values of $HDL_1,\;HDL_{2+3}$ratio than SO and BT groups. Major dietary fatty acids were more or less incorporated into serum phospholipid and triglyceride, resulting in the characteristic fatty acid profile of each dietary group. Incorporation of $C_{18:2}({\omega}_6)$ in SO groups were pronounced, but the degree of incorporation was lower in SHRs. In Mo groups, $C_{22:6}({\omega}_3)$ levels were inreased in triglyceride. It is suggested that these changes in serum lipid fatty acid composition are related to the different patterns of serum lipid by alteration of dietary fats.