Abstract: A method for combining an internal insulating sleeve and an external insulating sleeve of an antenna for a communication instrument, including the steps: a coil and positioning and electric connecting members are mounted in the internal insulating sleeve; the internal and external insulating sleeves are slipped one over the other, the internal insulating sleeve has a connecting section partially exposed to the outside; the internal and external insulating sleeves are closed to form a joint between them with a radial thickness for melting; the internal and the external insulating sleeves are sent into a melting machine in which the temperature for melting is set, and a transient electrical turning on for melting is done to combine the internal and external insulating sleeves integrally. The structural strength and durability of the antenna thus is largely increased.

Abstract: A gain structure of a stretchable antenna for mobile phones and especially of an antenna for minimized mobile phones, wherein, a quarter-wave coil antenna is built in a hole of a connecting member on the top of a mobile phone, one end of the coil antenna is pressed against a metallic conductive block in the connecting member; a spring sheet has its top folded end fixed on the metallic conductive block, and has the other end thereof extended in a hole provided on the top of the mobile phone to abut on an internal electric circuit board under a pressing force. A quarter-wave rod antenna is connected to the connecting member to be freely movable in and out of it. When the rod antenna is stretched out, a metallic bottom end sleeve thereof is pressed into the metallic conductive block to make electric connection therewith, this can increase gain in signal receiving and emitting of the minimized mobile phone.