Abstract: The present invention provides a power integrated device including a detection circuit and a determination circuit. The detection circuit detects whether first and second connection ports are coupled to a power source and produce first and second valid signals, respectively, and detect whether the power source coupled to the first and second connection ports meet first or second predetermined power values and produce first and second power spec signals, respectively. The determination circuit produces a system power-control signal according to the first valid signal, the second valid signal, the first power spec signal and the second power spec signal to turn on or turn off the power integrated device.

Abstract: The present invention provides a power integrated device including a detection circuit and a determination circuit. The detection circuit detects whether first and second connection ports are coupled to a power source and produce first and second valid signals, respectively, and detect whether the power source coupled to the first and second connection ports meet first or second predetermined power values and produce first and second power spec signals, respectively. The determination circuit produces a system power-control signal according to the first valid signal, the second valid signal, the first power spec signal and the second power spec signal to turn on or turn off the power integrated device.

Abstract: A transceiver with a receive/transmit fast switch function according to the invention is disclosed. In the transceiver, a frequency generator is used to generate a carrier signal which is fed into a transmitter and a receiver. Furthermore, a frequency transfer circuit and a frequency synthesizer are used to generate first, second and third local oscillation signals which are fed into the transmitter and the receiver. When transmitting a signal, the transmitter receives the carrier signal and the first local oscillation signal. The carrier signal is up converted by a mixer and then transmitted by the antenna. Inversely, when receiving a signal, the receiver receives the signal from the antenna, the receive signal is down converted in coordination with the second and third local oscillation signals and then outputted. Moreover, the receive signal can be demodulated into an FSK signal by a discriminator.

Abstract: A wireless LAN RF module uses parasitic element compensation devices in an antenna select circuit to improve port isolation. In addition, various combinations of RC filter networks and spurious radiation attenuators are incorporated into the Quad Demod/Mod and Synthesizer ;/circuits to provide suppression of EMI susceptibility and radiation throughout the RF module.

Abstract: A wireless LAN RF module uses a low power transistor switchable voltage divider circuit to control the bias input of a GaAs MESFET output power amplifier. This bias control circuit provides stable, high speed on-off switching of the power amplifier stage by applying low power bias voltages to the MESFET gate input, rather than by interrupting the high power MESFET drain to Vdd circuit.

Abstract: A broad-band microstrip antenna implemented using a dielectric base as its main body is disclosed. The base has two sides where the dual-mode resonator is located on the first side, while the grounded plane is located on the second side of the dielectric base. The dual-mode resonator has a high-frequency resonator and a low-frequency resonator, which are partially positioned in parallel. Due to the electric-magnetic effects, these two resonators are mutually coupled to significantly increase the operating bandwidth. In addition, there is a feed line on the first side of the dielectric base, which connects to the dual-mode resonator to provide signal transmission. In addition, there is a grounded mask in the antenna, which is located on the first side of the dielectric base, to provide sheltering for the feed line, and connect to the grounded plane to form a closed area to provide a more complete radiation field pattern.