LENGTH REDUCTION OF A RECTANGULAR GLOBAL POSITIONING SYSTEM ANTENNA OPERATING AT THE FREQUENCY OF 1.57542 GHz

摘要

A method is disclosed to drastically reduce the length and thus size of a global positioning system rectangular microstrip patch antenna operating in the LI band. This reduction in length to as little as approximately Xg/ 2 1 is accomplished by applying inductive symmetrical transverse inductive slits to the conducting plane of a microstrip patch antenna. The physical slits cut into the conducting plane of a microstrip patch antenna are equivalent to placing an inductor in series with the naturally capacitive shortened microstrip patch, causing series resonance and thus antenna functionality. Experimental testing of a miniaturised microstrip patch antenna prototype showed resonance at 1.58 GHz, an accuracy of 99%, after external fine tuning. The forward voltage reflection co-efficient, measured at that frequency, was -24.5 dB (-2 dB required) whilst the -3 dB bandwidth was 26 MHz (12 MHz minimum required). :1' 2' Figure 1: Transverse Inductive Slit - Electrical Equivalence. 'Wa= 39 mm Figure 2: Prototype - Shape without /, 4 feed line. M3 = -3 dB -M4 = -3 dB (a. 568GHz @ 1594 GHz -10 M1 = -9.687 dB @1 572 Gz M2 = -10.089 dB -20 @ 1.588 GHz 24.5 -30 Centre frequency = 1.58 GHz Figure 3: Prototype physical test sii characteristic.