الباب الرابع: شعر نازك الملائكة وبروین شاکر (دراسة مقارنة)

Impact of Covid-19 on Interest Rates

The global economy is experiencing a crisis due to the Covid-19 pandemic, the stock market index has collapsed. The rupiah exchange rate against the USA dollar weakened this was due to the large number of foreign investors leaving the Indonesian financial market, the stock market plummeted. The banking sector can carry out an economic stimulus given restructuring authority for all credit or financing without requiring restrictions on the credit ceiling or type of debtor, especially debtors for MSMEs and informal workers. The economic stimulus that needs to be maximized is prundential monetary and macro policies through lowering interest rates and maintaining stability in the rupiah exchange rate. Budget relocation is also enforced to maintain the availability of basic foodstuffs for the community, which has increased due to panic buying or market panic. Also providing assistance to increase people's purchasing power.

Reflect Arrays for High Gain Applications

This research work focuses on design and analysis of low-cost, single-layer broadband reflectarrays for X-band applications. Traditionally, parabolic reflectors and phased arrays were introduced to obtain the high gain. The disadvantages associated with traditional antenna types include: narrow bandwidth, high fabrication cost and complex feed networks. Recently, reflectarray antennas have been developed to overcome the disadvantages associated with parabolic reflectors and phased arrays. High gain reflectarray antennas are typically employed in radars, satellite communication and direct broadcasting applications. Four different type of delay-lines integrated reflectarray elements which include: single circular delay-line, pair of circular delay-lines, quad-meander and T-shape delay-lines are designed to obtain a broad linear phase range, high gain and good aperture efficiency. The reflectarray unit element performance is investigated in terms of phase range, Transverse Electric (TE) and Transverse Magnetic (TM) modes and far-field radiation patterns. The reflectarray unit element is analyzed by using circuit model technique and equivalent circuit results are verified through High Frequency Structure Simulator (HFSS™). The circuit model technique replaces the lengthy full-wave simulation of FEM method. This method provides fast and accurate calculation of electromagnetic parameters i.e. magnitude and phase range. The unit element shape and configurations are used to extract the lumped parameters and reflection characteristics. The reflectarray antenna system contains a feed horn antenna and an arrangement of phase shifting array elements. A hybrid Finite Element Boundary Integral (FEBI) method is used for electromagnetic modeling of reflectarray antenna system. The FEBI method provides accurate electromagnetic analysis of complex and medium-to-large sized structures. The reflectarray far-field radiation characteristics are obtained by using the hybrid FEBI method. The reflectarray antenna system model comprises of feed horn antenna and array of phase shifting elements. The feed horn antenna and array elements are designed separately. The effect of the incident angle, feed-to-diameter ratio and transmission modes can easily be considered in the FEBI based system simulations. The proposed reflectarray prototypes are fabricated and measured on a low-cost FR-4 substrate. The reflectarray antenna measurements are made in anechoic chamber. A gain of more than 20 dBi is realized for the proposed reflectarray configurations. The simulated and measured cross polarizations and side-lobe-levels are below -20 dB in all design configurations. More importantly, simulated results are in good agreement with the measured results.