http://nopr.niscpr.res.in/handle/123456789/36649 2026-10-09T18:37:08Z http://nopr.niscpr.res.in/handle/123456789/36799 Title: Characteristics & Design of High-gain Dielectric Circular Antennas Operated in X-Band Authors: Jamwal, K K S; Dhar, Atula Abstract: Characteristics of measured gain, VSWR, beam-width and the gain beam-width product (<i>Gθ²</i>) of circular dielectric rod antennas employing polymers are presented. Experimental parametric studies are made of antenna length <i>L</i>, diameter <i>D</i>₁ taper geometry, radiating-end diameter <i>D</i>₂ and the feed design to achieve optimized gain characteristics. Parametric curves are presented to show that for optimized gain performance the Hansen-Woodyard condition is in fair agreement with experiments. Design analysis is included for designing optimized gain circular dielectric antennas in the X-band frequencies (8.5-11.5GHz). The antenna gain beam-width products are also examined. Page(s): 126-128 1982-06-01T00:00:00Z http://nopr.niscpr.res.in/handle/123456789/36798 Title: Direction of Semi-diurnal Anisotropy in Relation to Interplanetary Magnetic Fields Authors: Agrawal, S P; Pathak, S P Abstract: A comparison of the direction of the maximum flux of the second harmonic of the daily variation of cosmic ray intensity observed at Deep River (<i>ɸ</i>₂), with the direction of the interplanetary magnetic field (<i>ɸ</i>_B), has been made for each day during 1973-75. The results show that, in general, the direction of <i>ɸ</i>₂ is perpendicular to <i>ɸ</i>_B, which is in agreement with the earlier observations as well as with the theoretical predictions. Page(s): 124-125 1982-06-01T00:00:00Z http://nopr.niscpr.res.in/handle/123456789/36797 Title: An Experimental Arrangement for Satellite RB Signal Amplitude Measurements Using Rotating Antenna Authors: Bardoloi, P; Rahman, K; Devi, M; Barbara, A K Abstract: A system to record amplitude variation and scintillation of R B sign al from a geostationary satellite is described. It uses the same rotating antenna of a radio phase meter used for Faraday rotation. Here, the received sign all for one complete rotation of the antenna is sample date four equidistant positions and these are averaged to obtain the amplitude of the signal. A further development in the set-up is also made to measure the ellipticity of the received signal. Page(s): 122-123 1982-06-01T00:00:00Z http://nopr.niscpr.res.in/handle/123456789/36796 Title: Comparison of Percentage Occurrence of Es at Karachi & Islamabad under Magnetic Conditions Authors: Majeed, Tariq Abstract: Generally, in fall the percentage occurrence of Es (when <i>f_o</i>Es <img src='http://www.niscair.res.in/jinfo/greaterequal.gif' border=0> 2 MHz) under quiet magnetic condition exceeds that under disturbed magnetic condition both at Karachi and Islamabad. However, the situation is reversed in winter. Page(s): 120-121 1982-06-01T00:00:00Z