Analysis of a low profile slotted microstrip antenna for cellular mobile radio

The TM/sub 01/ mode of a circular resonant microstrip cavity has been used to produce an omnidirectional vertically polarized antenna with a broadside null. Interlaced circumferential slots were added, resulting in reductions in the resonant frequency of up to 50%. The performance of this antenna when mounted on the roof of an automobile has been analyzed through the application of the geometric theory of diffraction (GTD). Chebychev matching networks have been investigated to implement a broadband impedance match to the antenna.<
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