Patent ID: 7176839

Claim:
An antenna unit adapted to be connected to an electronic device for transmitting a received radio signal to the electronic device, said antenna unit comprising: an antenna configured to receive a radio signal; a signal processing module configured to convert the radio signal received by said antenna into signal data to be transmitted to the electronic device; a substrate configured to carry said antenna and said signal processing module, said substrate having a circuit ground forming a ground of said signal processing module; a terminal interface configured to have an array of terminals for electrical connection with the electronic device, said terminal interface including a ground line leading from a ground terminal provided in the array of terminals to the circuit ground; an electromagnetic shield configured to surround said signal processing module so as to electromagnetically isolate the signal processing module from the antenna, said electromagnetic shield being electrically connected to the circuit ground; a case made of insulating resin, said case being configured to accommodate said antenna, said substrate, said signal processing module, said terminal interface, and said electromagnetic shield while exposing said array of terminals; wherein said antenna unit includes a noise canceller for canceling noise generated in the electronic device and transmitted to the circuit ground through the ground line, said noise canceller comprising a conductive stub piece one end of which is electrically connected to said electromagnetic shield and the other end of which is a free end, said stub piece having a length of about ¼ of a wavelength of the radio signal.