Small size antenna for broad-band ultra high frequency

摘要

A small size broad-band ultra high frequency antenna including a dielectric substance in the sleeve of an antenna body whereby approximating resonance frequency of the sleeve portion to resonance frequency of the body of the antenna so that a double-tuning circuit is formed thereby causing the impedance characteristics of the antenna to have double-peak characteristics within the working frequency band. The antenna further includes an impedance matching transformer for matching the impedance of the antenna to the characteristic impedance of a feeder line connected to the antenna, the matching transformer being composed of a coaxial type impedance transducer which has an opposite reactance component sufficient to offset the reactance component of the antenna and has the characteristic impedance convertible to the feeder line impedance.