Showing papers on "L band published in 1972"

Improved coupled-line microstrip circuit for L and S band oscillators

Abstract: The coupled-bar microstrip circuit described here utilises a TRAPATT diode, and is ideally suited for systems applications such as i.f.f. transponder-transmitter sources and airborne altimeter sources. It is compact and rugged and allows high-efficiency operation. This circuit has delivered 150 W with 30% efficiency at L band, 150 W with 26% efficiency at 3.5 GHz, and 120 W with 19% efficiency at 3.85 GHz. The devices were operated with 0.5 μs pulses up to 1% duty cycle in a near jitterfree operation.

Simultaneous L-band and VHF ionospheric fading effects at the geomagnetic equator

Abstract: Simultaneous observations of ionspheric fading of 1550 MHz and 136 MHz radio waves from the ATS-5 spacecraft were recorded on the geomagnetic equator at Ancon, Peru. The observations were made during a period around the 1971 spring equinox; they show fades as great as 27 db at 136 MHz, and 6 db at 1550 MHz. The general characteristics of the scintillation signatures at the two frequencies are discussed with emphasis on comparison of the two frequencies with respect to rates and depths of fades. Typical statistical distributions of signal levels are also presented from which time availabilities of the signals relative to the median levels can be derived.

Multipath propagation study for L-band, over-ocean, satellite-aircraft communication link

Abstract: The results are presented of a study of multipath propagation between an aeronautical relay satellite in synchronous earth orbit and an aircraft flying over the ocean. An analytical model for the reflected power is developed and the results of a computer solution are compared with an approximate solution obtained through integration by the method of steepest descent. The computer solution is shown to differ considerably from the approximate solution. Both methods are compared with the limited experimental results available.