Fixed dual frequency band antenna

A fixed dual frequency band antenna for use in a radio transceiver device wherein the two frequency bands are not harmonically related and the ratio between center frequencies of the two frequency bands is in the range from about two to about three, the antenna comprising:

• a fixed straight radiating antenna portion terminated by a helical wire radiating antenna portion, the total electrical length of said antenna being approximately three quarters of the wavelength at the center frequency of the higher of the two frequency bands;
• a conductive radiating cap terminating said helical wire portion;
• a conductive antenna base connected to said fixed straight portion at the end opposite said helical wire portion;
• and
• a matching circuit coupled between said radio transceiver device and said base, said matching circuit being arranged to substantially cancel the reactive portion of the impedance of the antenna for both frequency bands and to substantially equalize the resistive portion of the impedance of the antenna to the resistive portion of the output impedance of the radio transceiver device;
• wherein the length of said antenna is such that, together with said matching circuit, the resistive portion of the impedance of the antenna is substantially the same for both frequency bands.