Analysis of the characteristics of microstrip antennas in the decimeter wave range

Graphic dependences allowing one to promptly estimate the basic parameters of microstrip antennas (MSAs) are obtained for two frequency zones of decimeter wavelength range with central frequencies of 1600 MHz and 406 MHz, in which the equipment of satellite positioning systems (GPS, GLONASS, GALILEO, BEIDOU) and the COSPAS-SARSAT emergency radio beacon equipment operate. The influence of cuts in the MSA radiator that form a slow-wave structure (SWS) on the resonance frequency and frequency bandwidth of the antenna are studied. A technique of designing an MSA with circularly polarized radiated waves and this SWS is proposed, and the double impedance frequency band expansion is reached. The obtained bandwidth data are compared with theoretical limit values calculated from specified relation-ships that take into account the dissipative loss in the radiator. The MSA radiation efficiency is estimated.