Abstract: A dual-mode mobile terminal, which can access synchronous and asynchronous mobile communication systems, includes a key input panel and a controller. The key input panel includes a call switching key for switching between calls from the two systems and a call end key for ending calls from the two systems. While the terminal performs communication of one call received from one of the two systems in a general communication mode over a communication channel currently established by the one system, the controller determines whether an incoming call is received from the other system. If the incoming call is received, the controller notifies the user of receipt of the incoming call. If the call switching key is pressed, the controller prepares a communication environment for communication of the incoming call, allowing the user to perform the communication of the incoming call while maintaining the currently established communication channel.

Abstract: A pseudomorphic high electron mobility transistor (PHEMT) power device formed on a double planar doped epitaxial substrate and capable of operating with a single voltage source and a method for manufacturing the PHEMT power device are provided. The PHEMT power device includes: an epitaxial substrate including a GaAs buffer layer, an AlGaAs/GaAs superlattice layer, an updoped AlGaAs layer, a first doped silicon layer, a first spacer, an InGaAs electron transit layer, a second spacer, a second doped silicon layer having a different doping concentration from the first doped silicon layer, a lightly doped AlGaAs layer, and an undoped GaAs cap layer stacked sequentially on a semi-insulating GaAs substrate; a source electrode and a drain electrode formed on and in ohmic contact with the undoped GaAs cap layer; and a gate electrode formed on the lightly doped AlGaAs layer to extend through the undoped GaAs cap layer.

Abstract: A pseudomorphic high electron mobility transistor (PHEMT) power device formed on a double planar doped epitaxial substrate and capable of operating with a single voltage source and a method for manufacturing the PHEMT power device are provided. The PHEMT power device includes: an epitaxial substrate including a GaAs buffer layer, an AlGaAs/GaAs superlattice layer, an updoped AlGaAs layer, a first doped silicon layer, a first spacer, an InGaAs electron transit layer, a second spacer, a second doped silicon layer having a different doping concentration from the first doped silicon layer, a lightly doped AlGaAs layer, and an undoped GaAs cap layer stacked sequentially on a semi-insulating GaAs substrate, a source electrode and a drain electrode formed on and in ohmic contact with the undoped GaAs cap layer; and a gate electrode formed on the lightly doped AlGaAs layer to extend through the undoped GaAs cap layer.

Abstract: The dialogic style RF guidance system comprises multiple stationary base-sets established at the destination and the hand-held apparatus carried along by the visually handicapped people. This provides safe and efficient guidance to visually handicapped people in reaching their destinations, and more conveniently communicates with the base-set and simultaneously receives the message from the base-set through the microphones or external speakers.