This paper describes the numerical result on Circularly Polarized Printed Array antenna composed of Strips and Slots (CP-PASS) fed by stripline. The basic element consists of a slot and strip element with a "probe". In this paper, the input immittance of the strip element and the slot of CP-PASS are calculated by FDTD method. The calculated result confirms the mutual coupling between these elements, which was experienced in the experiments. In additon, the direction of parallel plate mode propagation was calculated by FDTD method, and we examined the parallel plate mode suppression with the shorting pins and the probe.
Electromagnetic wave-absorbers with thin structure and wide absorbing band using a lossy ferrite materials have been discussed. The system utilizing Ni-Zn ferrite materials were studyed and their matching thickness with matching relative band width were experimented and discussed. The absorption properties of the electromagnetic absorber of 0.45 cm in thickness and 0.66 GHz in bandwidth centered at 0.4 GHz is demonstrated as an experimental example.
We found out the optical coherent detection can be used as the Optical Beat Amplitude detection (OBDA) for the polarization modulation format. We investigated this technique both theoretically and experimentally.
Through an assessment test against interference with FM signals, the perceptible limits of CSO and CTB were -25dB and -34dB for MUSE, -18dB and -3ldB for NTSC respectively. CTB of -40dB and CNR of 32dB can be achieved after 2km transmission on a subscriber's optical fiber of the demand-access CATV system, when 8 channels were loaded on a FP-LD without an optical isolator. Assumed CTB of -4ldB and CNR of 25dB at a channel selector of a hub after 40 channels transmission on a trunk fiber, CTB of -37.5dB and CNR of 24.2dB are obtained at the subscriber's end.