Matsushita Electric Works, Ltd.

Kazuhiro Matsumoto

Masayuki Matsuo

Takashi Saeki

Hiroshi Chujo

Hideki Oka

Shinsuke Ueda

Naoyuki Noda

Kazunori Matsumoto

This antenna unit is adapted to be connected to an electronic device for transmitting a received radio signal to the electronic device. The antenna unit comprises a noise canceller for canceling noise generated in the electronic device and transmitted to the antenna unit through a ground line. The noise canceller is a conductive stub piece one end of which is electrically connected to an electromagnetic shield of the antenna unit and the other end of which is a free end. The stub piece has a length of about &#xbc; of a wavelength of the radio signal.

Antenna unit

A top loaded antenna unit is provided for concealed mounting within a vehicle below a covering or panel of dielectric material. The antenna unit includes a top load plate, a ground plate disposed in a spaced relation to the top load plate and electromagnetically coupled thereto through a matching element. The antenna unit additionally includes a dielectric member which is disposed in proximity to the top load plate for shifting resonance frequency of the antenna to a predetermined extent. The top load plate and the ground plate are assembled together with the dielectric member into a unitary structure for mounting within the vehicle below the covering or panel of dielectric material, at which condition resonance frequency of the antenna can be free from being affected from the covering or panel of the vehicle but affected solely from the dielectric member of which effect on the frequency shifting is known. Whereby, the antenna can give stable resonance frequency as intended only in consideration of the dielectric member and without being substantially influenced by other outside environments.

Concealedly mounted top loaded vehicular antenna unit

A top loaded antenna comprises a spaced pair of top load plate and a ground plate. A matching element integrally formed with a feedline and a shortline is disposed between the top plate and the ground plate for coupling between the plates, eliminating the necessity of separately and individually coupling the feedline element and shortline element to the plates.

Top loaded antenna

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Hirakata, Japan

Kazuhiro Matsumoto