Portable communication terminal

A cylindrical balance/unbalance transformer fitted around an antenna-side end of a coaxial cable for connecting a pair of antennas to a transmitting/receiving circuit, the first one of the antennas being used at a first frequency and the second one of the antennas being used at a second frequency higher than the first frequency, comprising:

• a first dielectric cylinder having a length corresponding to the first frequency;
• a second dielectric cylinder having a length corresponding to the second frequency, the second dielectric cylinder being coaxially fitted in the first dielectric cylinder;
• and
• a conductor cylinder coaxially fitted in the first dielectric cylinder and arranged beneath the second dielectric cylinder.

A portable communication terminal comprising:

• an antenna printed circuit board mounted on a main printed circuit board provided with a transmitting/receiving circuit;
• a pair of antennas mounted on the antenna printed circuit board, the first one of the antennas being used at a first frequency and the second one of the antennas being used at a second frequency higher than the first frequency;
• a coaxial cable for connecting the first and second antennas to the transmitting/receiving circuit;
• and
• a cylindrical balance/unbalance transformer fitted around an antenna-side end of the coaxial cable and usable at multiple frequencies, the balance/unbalance transformer including a first dielectric cylinder having a length corresponding to the first frequency, a second dielectric cylinder having a length corresponding to the second frequency, and a conductor cylinder, the second dielectric cylinder and the conductor cylinder being coaxially fitted in the first dielectric cylinder, wherein the antenna printed circuit board and the balance/unbalance transformer are electrically suspended from the main printed circuit board.